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Title: The Art of Paper-Making - A Practical Handbook of the Manufacture of Paper from Rags, Esparto, Straw, and Other Fibrous Materials, Including the Manufacture of Pulp from Wood Fibre
Author: Watt, Alexander
Language: English
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      Text enclosed by underscores is in italics (_italics_).

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THE ART OF PAPER-MAKING


      *      *      *      *      *      *

_WORKS BY THE SAME AUTHOR._


  Just ready. Fourth Edition, Revised and Enlarged. Crown 8vo,
  7s. 6d. cloth.

  THE ART OF SOAP-MAKING: A Practical Handbook of the Manufacture
  of Hard and Soft Soaps, Toilet Soaps, &c. Including many New
  Processes, and a Chapter on the Recovery of Glycerine from Waste
  Leys. With numerous Illustrations.

"Really an excellent example of a technical manual, entering as
it does, thoroughly and exhaustively, both into the theory and
practice of soap manufacture. The book is well and honestly done,
and deserves the considerable circulation with which it will
doubtless meet."--_Knowledge._


  Second Edition. Crown 8vo, 9s. cloth.

  THE ART OF LEATHER MANUFACTURE: Being a Practical Handbook, in
  which the Operations of Tanning, Currying, and Leather Dressing
  are fully Described, and the Principles of Tanning Explained, and
  many Recent Processes Introduced. With numerous Illustrations.

"A sound, comprehensive treatise on tanning and its accessories....
The book is an eminently valuable production."--_Chemical Review._


  Just Published. Third Edition, revised and much enlarged. 600 pp.,
  crown 8vo, 9s. cloth.

  ELECTRO-DEPOSITION: A Practical Treatise on the Electrolysis of
  Gold, Silver, Copper, Nickel, and other Metals and Alloys. With
  descriptions of Voltaic Batteries, Magneto and Dynamo-Electric
  Machines, Thermopiles, and of the Materials and Processes
  used in every Department of the Art, and several Chapters on
  ELECTRO-METALLURGY. With numerous Illustrations.

"Eminently a book for the practical worker in electro-deposition.
It contains minute and practical descriptions of methods, processes
and materials, as actually pursued and used in the workshop.
Mr. Watt's book recommends itself to all interested in its
subjects."--_Engineer._


  Just Published. Ninth Edition, enlarged and revised, 12mo, 4s. cloth.

  ELECTRO-METALLURGY: Practically Treated. Ninth Edition, Enlarged
  and Revised, with Additional Matter and Illustrations, including
  the most recent Processes.

"From this book both amateur and artisan may learn
everything necessary for the successful prosecution of
electro-plating."--_Iron._


  CROSBY LOCKWOOD & SON, 7, Stationers' Hall Court, London, E.C.

      *      *      *      *      *      *


THE ART OF PAPER-MAKING

A Practical Handbook of the Manufacture
of Paper from Rags, Esparto, Straw, and
Other Fibrous Materials, Including
the Manufacture of Pulp from
Wood Fibre

With a Description of the Machinery and Appliances used

To Which Are Added
Details of Processes for Recovering Soda from
Waste Liquors

by

ALEXANDER WATT

Author of "The Art of Soap-Making," "Leather Manufacture,"
"Electro-Metallurgy," "Electro-Deposition," etc., etc.



[Illustration: Capio Lumen (Publisher's colophon)]

London
Crosby Lockwood and Son
7, Stationers' Hall Court, Ludgate Hill
1890
[All rights reserved]

London:
Printed By J. S. Virtue and Co., Limited.
City Road.



PREFACE.


In the present volume, while describing the various operations
involved in the manufacture of paper, the Author has endeavoured to
render the work serviceable as a book of reference in respect to
the processes and improvements which have from time to time been
introduced, and many of which have been more or less practically
applied either at home or abroad.

The recovery of soda from waste liquors has been fully dealt with,
and the details of several applied processes explained.

Special attention has also been directed to some of the more
important methods of producing pulp from wood fibre, since it
is highly probable that from this inexhaustible source the
paper-maker will ultimately derive much of the cellulose used in
his manufacture. Indeed it may be deemed equally probable, when
the processes for disintegrating wood fibre, so largely applied
in America and on the Continent, become better understood in this
country, that their adoption here will become more extensive than
has hitherto been the case.

To render the work more readily understood alike by the practical
operator and the student, care has been taken to avoid, as far as
possible, the introduction of unexplained technicalities; at the
same time it has been the writer's aim to furnish the reader with a
variety of information which, it is hoped, will prove both useful
and instructive.

It is with much pleasure that the Author tenders his sincere thanks
to Mr. Sydney Spalding, of the Horton Kirby Mills, South Darenth,
for his kind courtesy in conducting him through the various
departments of the mill, and for explaining to him the operations
performed therein. To Mr. Frank Lloyd he also acknowledges his
indebtedness for the generous readiness with which he accompanied
him over the _Daily Chronicle_ Mill at Sittingbourne, and for
the pains he took to supply information as to certain details
at the Author's request. His best thanks are also due to those
manufacturers of paper-making machinery who supplied him with many
of the blocks which illustrate the pages of the book.

  BALHAM, SURREY, _January, 1890_.



CONTENTS.


  CHAPTER I.
  _CELLULOSE._

        PAGE

  Cellulose--Action of Acids on Cellulose--Physical Characteristics
      of Cellulose--Micrographic Examination of Vegetable Fibres--
      Determination of Cellulose--Recognition of Vegetable Fibres by
      the Microscope                                                   1


  CHAPTER II.
  _MATERIALS USED IN PAPER-MAKING._

  Raw Materials--Rags--Disinfecting Machine--Straw--Esparto Grass--
      Wood--Bamboo--Paper Mulberry                                     9


  CHAPTER III.
  _TREATMENT OF RAGS._

  Preliminary Operations--Sorting--Cutting--Bertrams' Rag-cutting
      Machine--Nuttall's Rag-cutter--Willowing--Bertrams' Willow
      and Duster--Dusting--Bryan Donkin's Duster or Willow--Donkin's
      Devil                                                           19


  CHAPTER IV.
  _TREATMENT OF RAGS_ (_continued_).

  Boiling Rags--Bertrams' Rag-boiler--Donkin's Rag-boiler--Washing
      and Breaking--Bertrams' Rag-engine--Bentley and Jackson's
      Rag-engine--Draining--Terrance's Drainer                        29


  CHAPTER V.
  _TREATMENT OF ESPARTO._

  Preliminary Treatment--Picking--Willowing Esparto--Boiling
      Esparto--Sinclair's Esparto Boiler--Roeckner's Boiler--Mallary's
      Process--Carbonell's Process--Washing Boiled Esparto--Young's
      Process--Bleaching the Esparto                                  40


  CHAPTER VI.
  _TREATMENT OF WOOD._

  I. CHEMICAL PROCESSES--Watt and Burgess's Process--Sinclair's
      Process--Keegan's Process--American Wood-pulp System--Aussedat's
      Process--Acid Treatment of Wood--Pictet and Brélaz's Process--
      Barre and Blondel's Process--Poncharac's Process--Young and
      Pettigrew's Process--Fridet and Matussière's Process            53


  CHAPTER VII.
  _TREATMENT OF WOOD_ (_continued_).

  Sulphite Processes--Francke's Process--Ekman's Process--Dr.
      Mitscherlich's Process--Ritter and Kellner's Boiler--
      Partington's Process--Blitz's Process--M'Dougall's Boiler for
      Acid Processes--Graham's Process--Objections to the Acid or
      Sulphite Processes--Sulphite Fibre and Resin--Adamson's
      Process--Sulphide. Processes--II. MECHANICAL PROCESSES--
      Voelter's Process for preparing Wood-pulp--Thune's Process      68


  CHAPTER VIII.
  _TREATMENT OF VARIOUS FIBRES._

  Treatment of Straw--Bentley and Jackson's Boiler--Boiling the
      Straw--Bertrams' Edge-runner--M. A. C. Mellier's Process--
      Manilla, Jute, &c.--Waste Paper--Boiling Waste Paper--Ryan's
      Process for Treating Waste Paper                                80


  CHAPTER IX.
  _BLEACHING._

  Bleaching Operations--Sour Bleaching--Bleaching with Chloride
      of Lime--Donkin's Bleach Mixer--Bleaching with Chlorine Gas
      (Glaser's Process)--Electrolytic Bleaching (C. Watt's Process)--
      Hermite's Process--Andreoli's Process--Thompson's Process--
      Lunge's Process--Zinc Bleach Liquor--Alum Bleach Liquor--New
      Method of Bleaching                                             89


  CHAPTER X.
  _BEATING OR REFINING._

  Beating--Mr. Dunbar's Observations on Beating--Mr. Arnot on
      Beating Engines--Mr. Wyatt on American Refining Engines--The
      Beating Engine--Forbes' Beating Engine--Umpherston's Beating
      Engine--Operation of Beating--Test for Chlorine--Blending      101


  CHAPTER XI.
  _LOADING.--SIZING.--COLOURING._

  Loading--Sizing--French Method of preparing Engine Size--Zinc
      Soaps in Sizing--Colouring--Animal or Tub Sizing--Preparation
      of Animal Size--American Method of Sizing--Machine Sizing--
      Double-sized Paper--Mr. Wyatt's Remarks on Sizing              114


  CHAPTER XII.
  _MAKING PAPER BY HAND._

  The Vat and Mould--Making the Paper--Sizing and Finishing          129


  CHAPTER XIII.
  _MAKING PAPER BY MACHINERY._

  The Fourdrinier Machine--Bertrams' Large Paper Machine--Stuff
      Chests--Strainers--Revolving Strainer and Knotter--
      Self-cleansing Strainer--Roeckner's Pulp Strainers--The
      Machine Wire and its Accessories--Conical Pulp-Saver--The
      Dandy-Roll--Water-Marking--De la Rue's Improvements in
      Water-Marks--Suction Boxes--Couch Rolls--Press Rolls--
      Drying Cylinders--Smoothing Rolls--Single Cylinder Machines    133


  CHAPTER XIV.
  _CALENDERING, CUTTING, AND FINISHING._

  Web-Glazing--Glazing Calender Damping Rolls--Finishing--Plate
      Glazing--Donkin's Glazing Press--Mr. Wyatt on American
      Super-Calendering--Mr. Arnot on Finishing--Cutting--Revolving
      Knife Cutter--Bertrams' Single-sheet Cutter--Packing the
      finished Paper--Sizes of Paper                                 154


  CHAPTER XV.
  _COLOURED PAPERS._

  Coloured Papers--Colouring Matters used in Paper-making--American
      Combinations for Colouring--Mixing Colouring Materials
      with Pulp--Colouring Paper for Artificial Flowers--Stains
      for Glazed Papers--Stains for Morocco Papers--Stains for
      Satin Papers                                                   165


  CHAPTER XVI.
  _MISCELLANEOUS PAPERS._

  Waterproof Paper--Scoffern and Tidcombe's Process--Dr. Wright's
      Process for preparing Cupro-Ammonium--Jouglet's Process--
      Waterproof Composition for Paper--Toughening Paper--Morfit's
      Process--Transparent Paper--Tracing Paper--Varnished Paper--
      Oiled Paper--Lithographic Paper--Cork Paper--New Japanese
      Paper--Blotting Paper--Parchment Paper--Mill and Cardboard--
      Making Paper or Cardboard with two Faces by ordinary
      Machine--Test Papers                                           174


  CHAPTER XVII.
  _MACHINERY USED IN PAPER-MAKING._

  Bentley and Jackson's Drum-Washer--Drying Cylinders--Self-acting
      Dry Felt Regulator--Paper Cutting Machine--Single-web
      Winding Machine--Cooling and Damping Rolls--Reversing or
      Plate-glazing Calender--Plate-planing Machine--Roll-bar
      Planing Machine--Washing Cylinder for Rag Engine--Bleach Pump--
      Three-roll Smoothing Presses--Back-water Pump--Web-glazing
      Calender--Reeling Machine--Web-ripping Machine--Roeckner's
      Clarifier--Marshall's Perfecting Engine                        184


  CHAPTER XVIII.
  _RECOVERY OF SODA FROM SPENT LIQUORS._

  Recovery of Soda--Evaporating Apparatus--Roeckner's Evaporator--
      Porion's Evaporator--Yaryan's Evaporator--American System
      of Soda Recovery                                               204


  CHAPTER XIX.
  _DETERMINING THE REAL VALUE OR PERCENTAGE
  OF COMMERCIAL SODAS, CHLORIDE OF LIME, ETC._

  Examination of Commercial Sodas--Mohr's Alkalimeter--Preparation
      of the Test Acid--Sampling Alkalies--The Assay--Estimation of
      Chlorine in Bleaching Powder--Fresenius' Method--Gay-Lussac's
      Method--The Test Liquor--Testing the Sample--Estimation of
      Alumina in Alum Cake, &c.                                      221


  CHAPTER XX.
  _USEFUL NOTES AND TABLES._

  Preparation of Lakes--Brazil-wood Lake--Cochineal Lake--Lac
      Lake--Madder Lake--Orange Lake--Yellow Lake--Artificial
      Ultramarine--Twaddell's Hydrometer--Imitation Manilla from
      Wood-pulp--Testing Ultramarines--Strength of Paper             235

  TABLES.--Dalton's Table showing the Proportion of Dry Soda in
      Leys of different Densities--Table of Strength of Caustic Soda
      Solutions at 59° F. = 150° C. (Tünnerman)--Table showing
      the Specific Gravity corresponding with the Degrees of Baumé's
      Hydrometer--Table of Boiling Points of Alkaline Leys--Table
      showing the Quantity of Caustic Soda in Leys of different
      Densities--Table showing the Quantity of Bleaching Liquid
      at 6° Twaddell (specific gravity 1·030) required to be added to
      Weaker Liquor to raise it to the given Strengths--Comparative
      French and English Thermometer Scales--Weights and
      Measures of the Metrical System--Table of French Weights
      and Measures                                                   241

  LIST OF WORKS RELATING TO PAPER MANUFACTURE                        246



THE ART OF PAPER-MAKING.



CHAPTER I.

_CELLULOSE._

  Cellulose.--Action of Acids on Cellulose.--Physical
  Characteristics of Cellulose.--Micrographic Examination of
  Vegetable Fibres.--Determination of Cellulose.--Recognition of
  Vegetable Fibres by the Microscope.


=Cellulose.=--Vegetable fibre, when deprived of all incrusting or
cementing matters of a resinous or gummy nature, presents to us the
true fibre, or _cellulose_, which constitutes the essential basis
of all manufactured paper. Fine linen and cotton are almost pure
cellulose, from the fact that the associated vegetable substances
have been removed by the treatment the fibres were subjected to in
the process of their manufacture; pure white, unsized, and unloaded
paper may also be considered as pure cellulose from the same cause.
Viewed as a chemical substance, cellulose is white, translucent,
and somewhat heavier than water. It is tasteless, inodorous,
absolutely innutritious, and is insoluble in water, alcohol, and
oils. Dilute acids and alkalies, even when hot, scarcely affect
it. By prolonged boiling in dilute acids, however, cellulose
undergoes a gradual change, being converted into _hydro-cellulose_.
It is also affected by boiling water alone, especially under high
pressure, if boiled for a lengthened period. Without going deeply
into the chemical properties of cellulose, which would be more
interesting to the chemist than to the paper manufacturer, a few
data respecting the action of certain chemical substances upon
cellulose will, it is hoped, be found useful from a practical point
of view, especially at the present day, when so many new methods of
treating vegetable fibres are being introduced.


=Action of Acids on Cellulose.=--When concentrated sulphuric acid
is added very gradually to about half its weight of linen rags
cut into small shreds, or strips of unsized paper, and contained
in a glass vessel, with constant stirring, the fibres gradually
swell up and disappear, without the evolution of any gas, and a
tenacious mucilage is formed which is entirely soluble in water.
If, after a few hours, the mixture be diluted with water, the
acid neutralised with chalk, and after filtration, any excess
of lime thrown down by cautiously adding a solution of oxalic
acid, the liquid yields, after a second filtration and the
addition of alcohol in considerable excess, a gummy mass which
possesses all the characters of _dextrin_. If instead of at once
saturating the diluted acid with chalk, we boil it for four or
five hours, the _dextrin_ is entirely converted into grape sugar
(_glucose_), which, by the addition of chalk and filtration, as
before, and evaporation at a gentle heat to the consistence of
a syrup, will, after repose for a few days, furnish a concrete
mass of crystallised sugar. Cotton, linen, or unsized paper, thus
treated, yield fully their own weight of gum and one-sixth of
their weight of grape sugar. Pure cellulose is readily attacked
by, and soon becomes dissolved in, a solution of oxide of copper
in ammonia (_cuprammonium_), and may again be precipitated in
colourless flakes by the addition of an excess of hydrochloric
acid, and afterwards filtering and washing the precipitate.
Concentrated boiling hydrochloric acid converts cellulose into a
fine powder, without, however, altering its composition, while
strong nitric acid forms nitro-substitution products of various
degrees, according to the strength of the acid employed. "Chlorine
gas passed into water in which cellulose is suspended rapidly
oxidises and destroys it, and the same effect takes place when
hypochlorites, such as hypochlorite of calcium, or bleaching
liquors, are gently treated with it. It is not, therefore, the
cellulose itself which we want the bleaching liquor to operate
upon, but only the colouring matters associated with it, and care
must be taken to secure that the action intended for the extraneous
substances alone does not extend to the fibre itself. Caustic
potash affects but slightly cellulose in the form in which we have
to do it, but in certain less compact conditions these agents
decompose or destroy it."--_Arnot._[1]


=Physical Characteristics of Cellulose.=--"The physical condition
of cellulose," says Mr. Arnot, "after it has been freed from
extraneous matters by boiling, bleaching, and washing, is of great
importance to the manufacturer. Some fibres are short, hard,
and of polished exterior, while others are long, flexible, and
barbed, the former, it is scarcely necessary to say, yielding
but indifferent papers, easily broken and torn, while the papers
produced from the latter class of fibres are possessed of a great
degree of strength and flexibility. Fibres from straw, and from
many varieties of wood, may be taken as representatives of the
former class, those from hemp and flax affording good illustrations
of the latter. There are, of course, between these extremes all
degrees and combinations of the various characteristics indicated.
It will be readily understood that hard, acicular[2] fibres do not
felt well, there being no intertwining or adhesion of the various
particles, and the paper produced is friable. On the other hand,
long, flexible, elastic fibres, even though comparatively smooth
in their exterior, intertwine readily, and felt into a strong
tough sheet.... Cotton fibre is long and tubular, and has this
peculiarity, that when dry the tubes collapse and twist on their
axes, this property greatly assisting the adhesion of the particles
in the process of paper-making. In the process of dyeing cotton,
the colouring matter is absorbed into the tubes, and is, as will
be readily appreciated, difficult of removal therefrom. Papers made
exclusively of cotton fibre are strong and flexible, but have a
certain sponginess about them which papers made from linen do not
possess."

Linen--the cellulose of the flax-plant--before it reaches the hands
of the paper-maker has been subjected to certain processes of
steeping or _retting_, and also subsequent boilings and bleachings,
by which the extraneous matters have been removed, and it therefore
requires but little chemical treatment at his hands. "Linen fibre,"
Arnot further observes, "is like cotton, tubular, but the walls of
the tubes are somewhat thicker, and are jointed or notched like a
cane or rush; the notches assist greatly in the adhesion of the
fibres one to another. This fibre possesses the other valuable
properties of length, strength, and flexibility, and the latter
property is increased when the walls of the tubes are crushed
together under the action of the beating-engine." From this fibre
a very strong, compactly felted paper is made; indeed, no better
material than this can be had for the production of a first-class
paper. Ropes, coarse bags, and suchlike are made from hemp, the
cellulose or fibre of which is not unlike that of flax, only it is
of a stronger, coarser nature. Manilla[3] yields the strongest of
all fibres. Jute, which is the fibre or inside bark of an Indian
plant (_Corchorus capsularis_), yields a strong fibre, but is very
difficult to bleach white. Esparto fibre holds an intermediate
place between the fibres just described and those of wood and
straw.... The fibre of straw is short, pointed, and polished, and
cannot of itself make a strong paper. The nature of wood fibre
depends, as may readily be supposed, upon the nature of the wood
itself. Yellow pine, for example, yields a fibre long, soft, and
flexible, in fact very like cotton; while oak and many other woods
yield short circular fibres which, unless perfectly free from
extraneous matters, possess no flexibility, and in any case are not
elastic.


=Micrographic Examination of Vegetable Fibres.=--The importance
of the microscope in the examination of the various fibres that
are employed in paper manufacture will be readily evident from
the delicate nature of the cellulose to be obtained therefrom.[4]
Amongst others M. Girard has determined, by this method of
examination, the qualities which fibres ought to possess to suit
the requirements of the manufacturer. He states that absolute
length is not of much importance, but that the fibre should be
slender and elastic, and possess the property of turning upon
itself with facility. Tenacity is of but secondary importance, for
when paper is torn the fibres scarcely ever break. The principal
fibres employed in paper-making are divided into the following
classes:--

  1. _Round, ribbed fibres_, as hemp and flax.

  2. _Smooth_, or _feebly-ribbed fibres_, as esparto, jute,
  phormium (New Zealand flax), dwarf palm, hop, and sugar-cane.

  3. _Fibro-cellular substances_, as the pulp obtained from the
  straw of wheat and rye by the action of caustic ley.

  4. _Flat fibres_, as cotton, and those obtained by the action of
  caustic ley upon wood.

  5. _Imperfect substances_, as the pulp obtained from sawdust.
  In this class may also be included the fibre of the so-called
  "mechanical wood pulp."


=Determination of Cellulose.= For the determination of cellulose
in wood and other vegetable fibres to be used in paper-making
Müller recommends the following processes:[5] 5 grammes weight
of the finely-divided substance is boiled four or five times in
water, using 100 cubic centimètres[6] each time. The residue is
then dried at 100° C. (212° Fahr.), weighed, and exhausted with
a mixture of equal measures of benzine and strong alcohol, to
remove fat, wax, resin, &c. The residue is again dried and boiled
several times in water, to every 100 c.c. of which 1 c.c. of strong
ammonia has been added. This treatment removes colouring matter and
pectous[7] substances. The residue is further bruised in a mortar
if necessary, and is then treated in a closed bottle with 250 c.c.
of water, and 20 c.c. of bromine water containing 4 c.c. of bromine
to the litre.[8] In the case of the purer bark-fibres, such as flax
and hemp, the yellow colour of the liquid only slowly disappears,
but with straw and woods decolorisation occurs in a few minutes,
and when this takes place more bromine water is added, this being
repeated until the yellow colour remains, and bromine can be
detected in the liquid after twelve hours. The liquid is then
filtered, and the residue washed with water and heated to boiling
with a litre of water containing 5 c.c. of strong ammonia. The
liquid and tissue are usually coloured brown by this treatment. The
undissolved matter is filtered off, washed, and again treated with
bromine water. When the action seems complete the residue is again
heated with ammoniacal water. This second treatment is sufficient
with the purer fibres, but the operation must be repeated as often
as the residue imparts a brownish tint to the alkaline liquid. The
cellulose is thus obtained as a pure white body; it is washed with
water, and then with boiling alcohol, after which it may be dried
at 100° C. (212° Fahr.) and weighed.


=Recognition of Vegetable Fibres by the Microscope.=--From
Mr. Allen's admirable and useful work on "Commercial Organic
Analysis"[9] we make the following extracts, but must refer the
reader to the work named for fuller information upon this important
consideration of the subject. In examining fibres under the
microscope, it is recommended that the tissues should be cut up
with sharp scissors, placed on a glass slide, moistened with water,
and covered with a piece of thin glass. Under these conditions:--

_Filaments of Cotton_ appear as transparent tubes, flattened and
twisted round their axes, and tapering off to a closed point at
each end. A section of the filament somewhat resembles the figure
8, the tube, originally cylindrical, having collapsed most in the
middle, forming semi-tubes on each side, which give the fibre,
when viewed in certain lights, the appearance of a flat ribbon,
with the hem of the border at each edge. The twisted, or corkscrew
form of the dried filament of cotton distinguishes it from all
other vegetable fibres, and is characteristic of the matured pod,
M. Bauer having found that the fibres of the unripe seed are
simply untwisted cylindrical tubes, which never twist afterwards
if separated from the plant. The matured fibres always collapse
in the middle as described, and undergo no change in this respect
when passing through all the various operations to which cotton is
subject, from spinning to its conversion into pulp for paper-making.

_Linen_, _or Flax Fibre_, under the microscope, appears as hollow
tubes, open at both ends, the fibres being smooth, and the inner
tube very narrow, and joints, or _septa_,[10] appear at intervals,
but are not furnished with hairy appendages as is the case with
hemp. When flax fibre is immersed in a boiling solution of equal
parts of caustic potash and water for about a minute, then removed
and pressed between folds of filter-paper, it assumes a dark yellow
colour, whilst cotton under the same treatment remains white or
becomes very bright yellow. When flax, or a tissue made from it,
is immersed in oil, and then well pressed to remove excess of
the liquid, it remains translucent, while cotton, under the same
conditions, becomes opaque.

_New Zealand Flax_ (_Phormium tenax_) may be distinguished from
ordinary flax or hemp by a reddish colour produced on immersing
it first in a strong chlorine water, and then in ammonia. In
machine-dressed New Zealand flax the bundles are translucent and
irregularly covered with tissue; spiral fibres can be detected in
the bundles, but less numerous than in Sizal. In Maori-prepared
phormium the bundles are almost wholly free from tissue, while
there are no spiral fibres.

_Hemp Fibre_ resembles flax, and exhibits small hairy appendages at
the joints. In Manilla hemp the bundles are oval, nearly opaque,
and surrounded by a considerable quantity of dried-up cellular
tissue composed of rectangular cells. The bundles are smooth, very
few detached ultimate fibres are seen, and no spiral tissue.

_Sizal_, _or Sisal Hemp_ (_Agave Americana_), forms oval fibrous
bundles surrounded by cellular tissue, a few smooth ultimate fibres
projecting from the bundles; is more translucent than Manilla, and
a large quantity of spiral fibres are mixed up in the bundles.

_Jute Fibre_ appears under the microscope as bundles of tendrils,
each being a cylinder, with irregular thickened walls. The
bundles offer a smooth cylindrical surface, to which the silky
lustre of jute is due, and which is much increased by bleaching.
By the action of hypochlorite of soda the bundles of fibres
can be disintegrated, so that the single fibres can be readily
distinguished under the microscope. Jute is coloured a deeper
yellow by sulphate of aniline than is any other fibre.



CHAPTER II.

_MATERIALS USED IN PAPER-MAKING._

  Raw Materials.--Rags.--Disinfecting Machine.--Straw.--Esparto
  Grass.--Wood.--Bamboo.--Paper Mulberry.

In former days the only materials employed for the manufacture of
paper were linen and cotton rags, flax and hemp waste, and some
few other fibre-yielding materials. The reduction of the excise
duty, however, from 3d. to 1½d. per lb., which took effect in the
first year of Her Majesty's reign--namely, in 1837--created a
greatly increased demand for paper, and caused much anxiety amongst
manufacturers lest the supply of rags should prove inadequate
to their requirements. Again, in the year 1861 the excise duty
was totally abolished, from which period an enormously increased
demand for paper, and consequently paper material, was created
by the establishment of a vast number of daily and weekly papers
and journals in all parts of the kingdom, besides reprints of
standard and other works in a cheap form, the copyright of which
had expired. It is not too much to say, that unless other materials
than those employed before the repeal of the paper duty had been
discovered, the abolition of the impost would have proved but of
little service to the public at large. Beneficent Nature, however,
has gradually, but surely and amply, supplied our needs through the
instrumentality of man's restless activity and perseverance.

The following list comprises many of the substances from which
cellulose, or vegetable fibre, can be separated for the purposes of
paper-making with advantage; but the vegetable kingdom furnishes
in addition a vast number of plants and vegetables which may also
be used with the same object. We have seen voluminous lists of
fibre-yielding materials which have been suggested as suitable
for paper-making, but since the greater portion of them are never
likely to be applied to such a purpose, we consider the time wasted
in proposing them. It is true that the stalks of the cabbage tribe,
for example, would be available for the sake of their fibre, but
we should imagine that no grower of ordinary intelligence would
deprive his ground of the nourishment such waste is capable of
_returning to the soil_, by its employment as manure, to furnish
a material for paper-making. Again, we have seen blackberries,
and even the pollen (!) of plants included in a list of paper
materials, but fortunately the manufacturer is never likely to be
reduced to such extremities as to be compelled to use materials of
this nature.


Raw Materials.

  Cotton rags.

  Cotton wool.

  Cotton waste.

  Cotton-seed waste.

  Linen rags.

  Linen waste.

  Hemp waste.

  Manilla hemp.

  Flax waste, etc.

  Jute waste, etc.

  China grass.

  Bamboo cane.

  Rattan cane.

  Banana fibre.

  Straw of wheat, etc.

  Rushes of various kinds.

  New Zealand flax.

  Maize stems, husks, etc.

  Esparto grass.

  Reeds.

  Woods of various kinds, especially white non-resinous woods, as
  poplar, willow, etc.

  Wood shavings, sawdust, and chips.

  Barks of various trees, especially of the paper mulberry.

  Peat.

  Twigs of common broom and heather.

  Mustard stems after threshing.

  Buckwheat straw.

  Tobacco stalks.

  Beetroot refuse from sugar works.

  Megass, or "cane trash"--refuse of the sugar cane after the juice
  has been extracted.

  Fern leaves.

  Tan waste.

  Dyers' wood waste.

  Old bagging.

  Old bast matting.

  Hop-bines.

  Bean stalks.

  Old canvas.

  Old rope.

  Gunny bags.

  Waste paper.

  Binders' clippings, etc.

  Old netting.

  Sailcloth.

  Sea grass (_Zostera marina_).

  Fibrous waste resulting from pharmaceutical preparations.

  Potato stalks.

  Stable manure.

  Silk cocoon waste.

  Oakum.

  Flax tow.

  Rag bagging.

  Leather waste.

  Tarpaulin. Etc., etc.


=Rags.=--Linen and cotton rags are imported into Great Britain
from almost all the countries of Europe, and even from the distant
states of South America, British South Africa, and Australasia. The
greater proportion, however, come from Germany. The rags collected
in England chiefly pass through the hands of wholesale merchants
established in London, Liverpool, Manchester, and Bristol, and
these are sorted to a certain extent before they are sent to the
paper-mills. By this rough sorting, which does not include either
cleansing or disinfecting, certain kinds of rags which would be
useless to the paper-maker are separated and sold as manure.
Woollen rags are not usually mixed with cotton rags, but are
generally kept apart to be converted into "shoddy." The importance
of disinfecting rags before they pass through the hands of the
workpeople employed at the paper-mills cannot be over-estimated,
and it is the duty of every Government to see that this is
effectually carried out, not only at such times when cholera and
other epidemics are known to be rife in certain countries from
which rags may be imported, but at all times, since there is no
greater source of danger to the health of communities than in the
diffusion of old linen and cotton garments, or pieces, which are
largely contributed by the dwellers in the slums of crowded cities.

Respecting the disinfecting of rags, Davis[11] thus explains the
precautions taken in the United States to guard against the dangers
of infection from rags coming from foreign or other sources.
"When cholera, or other infectious or contagious diseases exist
in foreign countries, or in portions of the United States, the
health officers in charge of the various quarantines in this
country require that rags from countries and districts in which
such diseases are prevalent shall be thoroughly disinfected before
they are allowed to pass their stations. Rags shipped to London,
Hull, Liverpool, Italian, or other ports, and re-shipped from such
ports to the United States, are usually subjected to the same rule
as if shipped direct from the ports of the country in which such
diseases prevail. It is usually requisite that the disinfection
shall be made at the storehouse in the port of shipment, by boiling
the rags several hours under a proper degree of pressure, or in a
tightly-closed vessel, or disinfected with sulphurous acid, which
is evolved by burning at least two pounds of roll sulphur to every
ten cubic feet of room space, the apartment being kept closed
for several hours after the rags are thus treated. Disinfection
by boiling the rags is usually considered to be the best method.
In the case of rags imported from India, Egypt, Spain, and other
foreign countries where cholera is liable to become epidemic, it
is especially desirable that some efficient, rapid, and thorough
process of disinfecting should be devised. In order to meet the
quarantine requirements, it must be thorough and certain in its
action, and in order that the lives of the workmen and of others
in the vicinity may not be endangered by the liberating of active
disease-germs, or exposure of decaying and deleterious matters, and
that the delay, trouble, and exposure of unbaling and rebaling may
be avoided, it must be capable of use upon the rags while in the
bale, and of doing its work rapidly when so used."


=Disinfecting Machine.=--To facilitate the disinfecting of rags
while in the bale, Messrs. Parker and Blackman devised a machine,
for which they obtained a patent in 1884, from which the following
abstract is taken.

Formerly rags and other fibrous materials were disinfected by being
subjected to germ-destroying gases or liquids in enclosed chambers,
but in order to render the disinfecting process effectual, it was
found necessary to treat the material in a loose or separated
state, no successful method having been adopted for disinfecting
the materials while in the bale. "This unbaling and loosening or
spreading of the undisinfected material is absolutely unsafe and
dangerous to the workmen, or to those in the vicinity, because of
the consequent setting free of the disease germs, and the exposing
of any decaying or deleterious matters which may be held in the
material while it is compressed in the bale. The unbaling and
necessary rebaling of the material for transportation also involves
much trouble and expense and loss of time. Large and cumbrous
apparatus is also necessary to treat large quantities of material
loosened or opened out as heretofore."

[Illustration: Fig. 1.]

It is specially necessary that rags coming from Egypt and other
foreign countries should be thoroughly disinfected by some rapid
and effectual means, which, while not endangering the health of
workmen employed in this somewhat hazardous task, will fully meet
all quarantine requirements. The apparatus devised by Messrs.
Parker and Blackman,[12] an abridged description of which is given
below, will probably accomplish this much-desired object.

[Illustration: Fig. 2.]

In the illustration, Fig. 1, A is the disinfecting chamber. At one
end is an opening A^1, and a door B, hinged at its lower edge and
adapted to be swung up, so as to close the opening tightly. For
supporting and carrying the bale C of material to be placed in the
chamber is a carriage C^1, consisting of a platform supported upon
wheels or castors _c c_. While the carriage is wholly within
the chamber A, as shown in Fig. 2, these wheels rest upon the
false bottom B^2; when the carriage is rolled back and out of the
chamber, as shown in Fig. 1, they roll upon the upper face of door
B swung down. The carriage is provided with a clamping device D
to hold the bale firmly and immovably. To cause the carriage to
move into and out of the chamber, the inventors provide upon the
under side of the platform a fixed sleeve E, interiorly threaded to
fit the screw E^1, journalled at one end near the opening in the
chamber end in a stationary block E^2 fixed upon the false bottom
B^2. From this end the screw extends along under the carriage
through the screw sleeve and to the other end of the chamber. A
collar _e_^2 on the screw bears against the inner end of this
journal-bearing, and upon the end of the shank _e_ bearing against
the other end of the journal is fixed a pinion F, which is to be
driven in either direction as desired. Above this journal-bearing
is a series of similar bearings (five being shown), G G, passing
through the wall of the chamber. Of these the middle one is in
a line with the centre of the bale, supported and held on the
carriage. The others are arranged at the corners of a square.
Journalled in these bearings are the hollow shanks H H of the
hollow screws I I pointed at I^1 I^1. Each screw is perforated,
_i i_, between the threads _i_^1 _i_^1 from the fixed collar K K.
Upon the tubular shanks H H of the screws are fixed the gear-wheels
L L. At a short distance from the end of the chamber, A is the
hollow chamber or receptacle M, into which is to be forced the
disinfectant liquid or gas. The tubular shanks H H of the screws
project through the wall M, passing through stuffing-boxes _m m_,
and their bores communicate with the interior of the chamber, the
shank of the middle screw being continued through the opposite
wall and a stuffing-box, its solid or projecting end being provided
with two fixed pulleys, N N, and a loose pulley O. When a gaseous
disinfectant is used, it can be forced by any desired means through
the pipe S into the chamber. Where a liquid disinfectant is used,
an elevated tank R containing the fluid may be used. As most
fibrous materials, and especially rags, are baled so as to be in
layers, it is preferable so to place the bale upon the carriage
that the perforated screws may penetrate the material at right
angles to the layers by which the gas or liquid issuing through the
holes in the screws passes in all directions throughout the mass
within the bale.

In the upper part of chamber A are perforated shelves V V, upon
which, if desired, the material can be spread out and subjected to
disinfecting gas or vapour. On the top of the chamber is a tank
W nearly filled with disinfecting liquid. A passage W^1 extends
from upper part of the chamber up into the tank above the level of
the liquid therein, and is then carried at its end down below the
surface of the liquid. At its other end the tank is provided at its
top with a discharge opening X and a suitable pipe X^1, forming a
continuation of the opening; by this means all foul and deleterious
vapours or gases passing out of the closed chamber A through the
passage W must pass through the disinfecting liquid in the tank
before escaping through the opening X and stack X^1 into the air,
and are thus rendered harmless.

When a sufficient amount of the disinfectant has been forced into
and through the bale, the disinfectant is turned off, and cold dry
air can be forced through chamber M, and out through the nozzles
and bale, whereby the material within the bale becomes cooled and
dried, and all the foul air from the chamber A driven out, so that
it may be opened and entered with safety. Any suitable disinfectant
may be used with this apparatus, as, for example, sulphurous acid,
in gas or solution, superheated steam, carbolic acid, or any
solution or vapour containing chlorine.


=Straw.=--Very large quantities of this material are used in the
manufacture of paper, but more especially for newspapers, the straw
from wheat and oats being mostly employed. Although the percentage
of cellulose in straw is about equal to that of esparto, the severe
treatment it requires to effectually remove the silicious coating
by which the fibre is protected, and to render the knots amenable
to the action of the bleach, greatly reduces the yield of finished
pulp. Many processes have been introduced for the treatment of
straw for paper-making, but the most successful of them appear to
be modifications of a process introduced in 1853 by MM. Coupier and
Mellier.


=Esparto Grass.=--This important fibrous material is largely
imported from Algeria, Spain, and other countries, and constitutes
one of the most valuable fibre-yielding materials with which the
manufacturer has to deal. Some idea of the amount of esparto and
other fibres which find their way to our shores may be gleaned
from the fact that while the import of cotton and linen rags in
the year 1884 was 36,233 tons, of the value of £487,866, that of
esparto and other fibres amounted to 184,005 tons, of the value of
£1,125,553.


=Wood.=--As a paper-making material, the fibre obtained from
various kinds of wood now holds an important position, since
the sources of supply are practically inexhaustible. The first
practical process for manufacturing pulp from wood fibre was
perfected and introduced by the author's father, the late Mr.
Charles Watt, who, in conjunction with Mr. H. Burgess, obtained
a patent for the invention on August 19th, 1853. The process was
afterwards publicly exhibited at a small works on the Regent's
Canal, when the Earl of Derby (then Lord Stanley), many scientific
men and representatives of the press, were present, and expressed
themselves well satisfied with its success. Specimens of the wood
paper, including a copy of the _Weekly Times_ printed thereon,
were exhibited, as also some water-colour drawings which had
been produced upon paper made from wood pulp. Failing to get the
process taken up in England, an American patent was applied for and
obtained in 1854, which was subsequently purchased; but with the
exception of an instalment, the purchase-money was never paid to
the inventor! Thus the process "got" into other hands, the original
inventor alone being unbenefited by it.

It has been repeatedly stated,[13] no doubt unwittingly, that a
person named Houghton first introduced the wood paper process into
this country; but considering that his patent was not obtained
until 1857, or four years after the process above referred to was
patented and publicly exhibited in England, it will be seen that
the statement is absolutely without foundation. The first knowledge
Mr. Houghton received concerning wood as a paper-making material
was from the author's father, and he (Mr. Houghton), in conjunction
with Mr. Burgess, introduced the Watt and Burgess process into
America in the year 1854. These are the facts.


=Bamboo= (_Bambusa vulgaris_).--The leaves and fresh-cut stems of
this plant are used for paper material, but require to pass through
a preliminary process of crushing, which is effected by suitable
rolls, the second series of crushing rolls being grooved or
channelled to split or divide the material, after which the stems
are cut to suitable lengths for boiling.


=Paper Mulberry= (_Broussonetia papyrifera_).--The inner bark of
this tree, and also some other basts, have long been used by the
Japanese and Chinese in the manufacture of paper of great strength,
but of extreme delicacy.



CHAPTER III.

_TREATMENT OF RAGS._

  Preliminary Operations.--Sorting.--Cutting.--Bertrams' Rag-cutting
  Machine.--Nuttall's Rag-cutter.--Willowing.--Bertrams' Willow and
  Duster.--Dusting.--Bryan Donkin's Duster or Willow.--Donkin's
  "Devil."


=Preliminary Operations.=--Before the rags are submitted to the
various processes which constitute the art of paper-making, they
are subjected to certain preliminary operations to free them
from dirty matters, dust, and even sand, which is sometimes
fraudulently introduced into rags to increase their weight. This
preliminary treatment may be classified under the following heads,
namely:--Sorting; Cutting; Willowing; Dusting.


=Sorting.=--The rags being removed from the bags or bales in which
they are packed, require first to be sorted according to the nature
and quality of the fabrics of which they are composed; thus linen,
cotton, hemp, wool, &c., must be carefully separated from each
other; the thickness of the substance, its condition as to the
wear it has undergone, and the colour of the material, all these
considerations are taken into account by the women and girls who
are employed in the operation of sorting. The finer qualities are
set aside for writing-paper, inferior sorts being used separately,
or mixed, according to the requirements of the manufacturer.
Blue rags are generally separated from the rest and kept for the
manufacture of blue paper, but most of the other coloured rags
require bleaching. In sorting rags, a good deal of judgment and
skill are required to avoid mixing the better qualities with
those of an inferior class, which would occasion loss in the
manufacture. It is also important that those of inferior colour
should not be mixed with the finer qualities, which would be liable
to affect the colour and deteriorate the quality of the paper.
Paper manufacturers generally classify the rags obtained from home
sources, that is, from different parts of the United Kingdom, under
the following heads:--

HOME RAGS.

  New cuttings.
  Linen pieces.
  Cotton pieces.
  Fines (whites).
  Superfines (whites).
  Outshots (whites).
  Seconds (whites).
  Thirds (whites).
  Colours or prints.
  Blues.
  Gunny, clean.
  Gunny, dirty.
  Rope (white).
  Rope (hard).
  Rope, bagging, etc.

Foreign rags are distinguished as below:--

BELGIAN RAGS.

  White linens.
  Mixed fines (linens and cottons).
  Grey linens.
  Strong linens.
  Extra fine linens.
  Blue linens.
  Superfine white cottons.
  Outshot cottons.
  Seconds.
  Half jute and linen.
  Light prints.
  Mixed prints.
  Blue cottons.
  Fustians.
  Black calicoes.
  White hemp, strings, and rope.
  Tarred hemp, strings, and rope.
  Jute spinners' waste.
  Jute waste.

_New._

  White linens.
  Grey linens.
  Blue linens.
  Unbleached cottons.
  White linens and cottons.
  Print cuttings (free from black).
  Blacks.
  Fustians.

FRENCH RAGS.

  French linens.
  White cotton.
  Knitted cotton.
  Blue cotton.
  Coloured cotton.
  Black cotton.
  Marseilles whites.
  Light prints.
  Mixed prints.
  New white cuttings.

GERMAN RAGS.

  S. P. F. F. F.
  S. P. F.
  F. F.
  F. G.
  L. X. F.
  L. F. R. blue.
  C. S. P. F. F. F.
  C. F. B. blue.
  C. F. X. coloured.

TRIESTE.

  P. P. white linen (first).
  P. white linen (second).
  S. fine greys.
  X. coloured cottons.

LEGHORN.

  P. L. linens.
  P. C. cottons.
  S. C.
  T. C.

TURKEY AND BEYROUT.

  Bright reds.

ALEXANDRIA.

  Whites.
  Blues.
  Colours.

BALTIC AND RUSSIAN.

  S. P. F. F.
  S. P. F.
  L. F. B.
  F. G.
  F. F.
  B. G.
  L. F. X.

Woollen rags are only used to a very moderate extent in blotting
and filtering papers and also in coarse papers and wrappers. Many
attempts have been made to bleach woollen rags, but the severity
of the treatment required invariably ended in a destruction of the
fibrous substances mingled with them. It is customary to dispose
of such material for re-making into common cloths, and for shoddy.
Rags collected in large cities, in consequence of the frequent
bleachings they have been subjected to, are considerably weakened
in fibre, tearing easily, and are therefore subject to loss in
process of manufacture into pulp. Country rags, being coarser and
greyer because less bleached, are stronger in fibre and give a
better body to the paper. In sampling rags it is necessary to take
precautions against the fraudulent "tricks of the trade," which
are often resorted to to cheat the manufacturer. Samples should
be taken from the interior of the bags or bales, to ascertain
if the material in the interior is equal in quality with that at
the outside--that is to say, that the quality is fairly averaged
throughout. It may also be found that the rags have been purposely
wetted to increase their weight. If such is found to be the case, a
few handfuls should be weighed, and then dried in a warm room, and
afterwards re-weighed, when if the loss exceeds 5 to 7 per cent. it
may be assumed that the rags have been fraudulently wetted. It is
generally found, however, that the merchants in the principal towns
transact their business honourably and are therefore reliable.

The sorting is generally performed by women, who not only separate
the various qualities of the rags, which they place in separate
receptacles, but also remove all buttons, hooks and eyes,
india-rubber, pins and needles, &c., and loosen all seams, hems
and knots. The rags are next carefully looked over by women called
_over-haulers_, or over-lookers, whose duty it is to see that the
previous operations have been fully carried out in all respects.
Usually there is one over-hauler to every eight or ten _cutters_.


=Cutting.=--In some mills it is preferred to have the rags cut
into pieces from 2 to 4 inches square, but the actual size is not
considered of much importance. The chief object is to have them in
such a condition that they may be thoroughly cleansed in subsequent
operations, and able to float throughout the water in the
rag-engine, without twisting round the roller. If the rag pieces
are smaller than is required to effect this it tends to create a
loss of fibre in the operations of willowing and dusting.

[Illustration: Fig. 3.]

The process of cutting is performed by hand or by machinery. When
the rags are cut by hand, the operation, which is accomplished by
women, is conducted as follows:--The cutter takes her place in
front of an oblong box, as in Fig. 3, covered with coarse wire
netting, containing three threads per inch, through which dust,
&c., passes to a receptacle beneath; in the centre is fixed, in
a slanting position, a large-bladed knife of peculiar form, with
its back towards the operator, who is surrounded by a number of
boxes, corresponding with the number of the different qualities of
rags; these are lined at the bottom with coarse wire gauze. In the
operation of cutting, if any foreign substances, such as buttons,
hooks, &c., which may have escaped the sorters are found, these are
at once removed. The rags as they are cut are put into baskets to
be conveyed to the rag-engine room. In some mills rags are cut by
machinery, but hand cutting is usually adopted for the better kinds
of paper, as it is obvious that the machine would not be able to
reject, as is the case in hand cutting, unpicked seams and other
irregularities which may have escaped observation by the sorters
and overhaulers. Machine cutting is, therefore, generally adopted
for the materials which are to be used for the coarser papers.
There are several rag-cutting machines in use, of which one or two
examples are given below.


[Illustration: Fig. 4.]

=Bertrams' Rag-Cutting Machine.=--The engraving, Fig. 4, represents
a machine manufactured by Messrs. Bertrams, Limited, of St.
Katherine's Works, Edinburgh, to whose courtesy we are indebted
for this and other illustrations of their machinery, which have
been reproduced in outline from their illustrated catalogue. The
machine, which is suitable either for rags or ropes, has three
revolving knives, and one dead knife, which is rendered reversible
to four edges, and has self-acting feed gear, side frames, drum,
and other connections of substantial construction; it is wood
covered, and furnished with sheet-iron delivery spout. The
material passes into the machine along the table at _a_, where it
passes between the dead knife _c_ and the knives _b_ fixed to the
revolving drum _d_. The cut rags fall into a receptacle beneath the
drum.


=Nuttall's Rag Cutter.=--Another type of rag cutter, and which is
also suitable for cutting bagging, sailcloth, tarpaulin, Manilla
and other fibres, is Nuttall's Rag Cutter, a drawing of which is
shown in Fig. 5. This machine is manufactured by Messrs. Bentley
and Jackson, of Bury, near Manchester, and is generally known as
the "Guillotine Rag Cutter," from the principle of its action,
which is that of chopping the material. The machine is adopted at
many mills, and a large-sized machine has recently been put down at
the _Daily Telegraph_ mills, Dartford. A medium-sized machine will
cut about one ton of rags in an hour.


[Illustration: Fig. 5.]

=Willowing.=--In some mills the cut rags are conveyed to a machine
called the "willow," which in one form of machine consists of
two cast-iron cylinders, 2½ feet in diameter and 3½ feet wide,
provided with numerous iron teeth, which project about 4 inches.
These cylinders are placed one behind the other, and beneath them
is a semi-circular screw, and above them a cover of the same
form. This cover is also furnished with teeth, and is so adjusted
that the teeth in the cylinders pass those in the cover at a
distance of ½ to ¾ of an inch. In front are a pair of rollers and
revolving apron, which carry the rags into the cylinders, which
rotate rapidly; and the rags, which are thrown by the first into
the second cylinder, are allowed to remain in them for about 20
seconds, when a sliding door, which rises three times per minute,
allows the rags to be discharged into a duster. Each time the
sliding door opens the revolving apron moves forward and recharges
the willow with a fresh supply. The rags, after being beaten and
teazed in the willow, are considerably loosened in texture, and
a good deal of dust and gritty matters fall through the screen
beneath.

[Illustration: Fig. 6.]

Fig. 6 represents a combined willow and duster, specially
useful for waste rags and jute, but may be used for all fibres,
manufactured by Bertrams, Limited, the main features of which are
thus described:--"There are two drums, which have malleable-iron
cross-bars and teeth, and malleable-iron harp motion below for
escape of dust. The framework of the willow is of cast iron, and
the sides are filled in with cast-iron panel doors, the top being
covered in with sheet iron. The gear is arranged so that the willow
will deliver to the duster or otherwise by self-acting motion
continuously or intermittently. The feed to the willow can also be
made continuous or intermittent. The drums, framework, panels, and
casing being made of iron, the chance of fire from the friction of
its working is reduced to a minimum. The duster, as a rule, is 12
feet long, about 5 feet in diameter, and has eight longitudinal
bars of cast iron fitted between the front and end revolving
rings. These bars are fitted with malleable-iron spikes, pitched
and so arranged that the rags or fibres are delivered at the exit
end automatically. The outside of the duster can be lined with
wire-cloth, perforated zinc, iron, etc. It is driven by outside
shafts and friction gear, so that there is no internal shaft to
interfere with the delivery of the fibres."


[Illustration: Fig. 7.]

=Dusting.=--In Fig. 7 is shown a rag-dusting machine, manufactured
by Messrs. Bryan Donkin and Co., of Bermondsey, London. The
cylinder of this machine, which is conical in form, to enable the
rags to travel from one end to the other, whence they are ejected,
revolves, as also does a second cylinder of a skeleton form, but
in the opposite direction. Each cylinder is fitted with knives, or
spikes--those of the outer cylinder projecting towards the centre;
the knives of the centre cylinder being attached to its exterior
surface: when the machine is in motion the two sets of blades pass
each other so that when the rags come between them the action is
that of scissors. When the rags are ejected at the end of the
cylinder, they pass into another cylinder of wire, through which
the dust falls and leaves them in a fairly clean condition, when
they are lowered through a trap-door to the boiling room below.


[Illustration: Fig. 8.]

=Donkin's "Devil."=--For removing the dust and dirt from coarse
and very dirty rags, oakum, rope, etc., the presence of which
would seriously injure the quality of the paper, a still more
powerful machine has been introduced, called the "devil," which is
constructed on the same principle as the willow, but revolves at a
lower speed. The revolving axle of this machine is conical, and is
provided with teeth, arranged in a spiral form. The case in which
it rotates is fed continuously, instead of intermittently; and
although it facilitates the subsequent treatment of the fibre, it
is said to be wasteful, while also consuming a considerable amount
of power. A machine, or "devil," for cleaning rags or half stuff is
manufactured by Messrs. Donkin and Co., a representation of which
is shown in Fig. 8.



CHAPTER IV.

_TREATMENT OF RAGS_ (_continued_).

  Boiling Rags.--Bertrams' Rag Boiler.--Donkin's Rag Boiler.--
  Washing and Breaking.--Bertrams' Rag Engine.--Bentley and
  Jackson's Rag Engine.--Draining.--Torrance's Drainer.


=Boiling Rags.=--To remove greasy matters, and also to dissolve out
the cementing substances from the stems of flax and shell of the
cotton, the rags are next boiled in a solution of caustic soda,
caustic lime, or a mixture of carbonate of soda and lime. The
boiling has also the effect of loosening the dirt contained in the
rags, whereby the colour of the material is greatly improved, while
at the same time it is rendered more susceptible to the action of
the bleaching agent. Strong linen rags will sometimes lose from
one-third to one-fifth of their weight by the process of boiling.
The vessels for boiling rags are of various construction, and have
been the subject of numerous ingenious patents. These boilers
are either cylindrical or spherical, and are also stationary or
rotary--the latter form being devised for the purpose of keeping
the caustic alkali solution freely diffused throughout the mass of
fibre during the boiling.


[Illustration: Fig. 9.]

=Bertrams' Rag Boiler.=--An illustration of a spherical boiler, as
manufactured by Bertrams, Limited, of Edinburgh, is given in Fig.
9. The shell of this boiler is made from malleable iron, is 8 feet
in diameter and 9 feet deep. The boiler is constructed on what is
termed the "vomiting" principle, by which a free circulation of the
alkaline liquor is constantly maintained. These boilers are made
to withstand any pressure of steam, but the size given is usually
worked at from 35 to 45 lbs. pressure, and carries about 30 cwt. of
dry esparto.


[Illustration: Fig. 10.]

=Donkin's Rag Boiler.=--The spherical boiler of Messrs. Bryan
Donkin and Co. is shown in Fig. 10. Being of a spherical form, it
is twice as strong as a cylindrical boiler of the same diameter
and thickness. The plates used are, notwithstanding, of the usual
substance, thus rendering it perfectly safe, durable, and suitable
for high-pressure steam. The spherical shape also allows the rags
to fall out by themselves when the boiler is revolving with the
cover off. Within the boiler are strainers to carry off the dirt,
and lifters to agitate the rags during the process of either
boiling or washing. To avoid cement, or even lead joints, the
gudgeons and the boiler are turned true in the lathe to fit each
other, the joints being simply made with red lead. These boilers
are usually about 8 feet in diameter, and are capable of boiling
from 20 cwt. to 25 cwt. of rags. The idea of giving motion to the
boiler, so as to insure a perfect mixture of the rags and the
caustic liquor, is of American origin, and was first introduced
into this country by Messrs. Bryan Donkin and Co. It is usual to
fix the boiler so that it can be fed with rags through a trap in
the floor above, while the boiler is in a vertical position and the
lid removed. The trunnions are hollow, to admit the introduction
of steam, alkaline ley, or water, and its rotary motion, which is
about three times in two minutes, is given by the gearing on the
left of the illustration.

The alkalies used for boiling rags are either caustic soda, soda
ash, slaked lime, made into a cream and sifted, or a mixture of
slaked lime and carbonate of soda. A description of the preparation
of caustic soda ley will be found in another chapter. It has been
customary at most of the larger paper-mills to purchase their
caustic soda direct from the alkali manufacturers, who supply
it in a solid form enclosed in iron drums, hermetically closed,
which are broken and the contents removed and dissolved when
required for use. As to the strength of caustic soda liquor to be
used for boiling rags, this is regulated according to the nature
and condition of the material, and the quality of the paper it
is intended for (see p. 34). For the finest papers the caustic
soda should be perfectly pure, and as there are various grades of
this chemical substance sold by the alkali makers, only the purer
qualities are used for the better kinds of paper. The proportion
of caustic soda per cwt. of rags varies to the extent of from 5 to
10 per cent. of the former to each cwt. of the latter, the coarser
materials, of course, requiring more alkali than those of finer
quality. In cases where rags are boiled in an open boiler--as
was formerly the case--a much larger proportion of caustic soda
would be required than when the boiling is conducted under high
pressures, as is now very generally the custom. In boiling the
finer qualities of rags, less pressure of steam is required than
for the coarser qualities, and the heat being proportionately
lower, there is less destruction of the fibre. Some paper-makers
prefer to boil the rags with caustic lime only, in which case the
lime, after being slaked in the usual way, is mixed with water
until it attains a milky consistence, when it is passed through a
sieve to separate any solid particles which may be present. About
the same percentage of lime may be used as in the former case.

When a mixture of lime and carbonate of soda is used, a method
much adopted on the Continent, the lime should be well screened
from lumps before being mixed with the soda. The usual method
of preparing this mixture is as follows:--A wooden tank, 15
feet long, 5 feet wide, and 4 feet deep is divided into three
compartments, each of which has a false bottom perforated with
½-inch holes to keep back lumps, stones, pieces of coal, etc.,
which frequently abound in the lime. The fresh lime is put into the
first compartment, where it is slaked with water in the usual way;
the resulting powder is then put into the next compartment together
with sufficient water, where it is agitated until converted into
what is technically termed "milk of lime." In the partition which
separates the second from the third division is a movable sluice,
through which the milk of lime flows into the third compartment; in
this is fitted a revolving drum, similar to the drum-washer of the
breaking-engine, through which the milk of lime which flows from
the sluice becomes strained, and is lifted in the same way as water
is lifted by the drum-washer of the breaking-engine, and is thence
discharged through a pipe into the rag boilers; an additional
straining can be effected by placing a fine wire strainer over
the mouth of this pipe leading to the boiler, which will prevent
objectionable particles from entering the boiler. Each compartment
is provided with a large waste pipe, through which, by the aid of a
sufficient supply of water, all impurities which have been rejected
by the drum are carried away. The soda solution is prepared by
dissolving the required proportion in water, and the resulting
liquor, after careful straining, is introduced into the boiler to
which the charge of rags has been given; the head of the boiler is
then fixed in its position and steam turned on, until a pressure of
about 20 to 30 lbs. to the square inch is attained, and the boiling
kept up for two to six hours, according to the quality of the rags.
By the Continental system of boiling rags, for No. 1 stuffs, 216
lbs. of lime and 114 lbs., of 48 per cent., soda ash are used for
every 4,000 lbs. of rags; for Nos. 3 and 5 stuffs, 324 lbs. of lime
and 152 lbs. of soda ash are used; and for No. 4 stuff 378 lbs. of
lime and 190 lbs. of soda ash, and the boiling in each case is kept
up for twelve hours, under a pressure of 30 lbs., the operation
being conducted in boilers which revolve horizontally.

In boiling the finest qualities of rags, it is considered
preferable to boil with lime alone, which is believed to be less
injurious to delicate fibres than caustic soda. Dunbar[14] gives
the following proportions of 70 per cent. caustic soda per cwt. of
rags:--

S. P. F. F. F. is boiled with lime alone, then washed in the
boiler, and again boiled with 2 per cent. of soda ash.

  S. P. F. F. is boiled with 12 lbs. of (70%) caustic soda per cwt.
  S. P. F          "      "  14      "    "        "          "
  Fines            "      "   7      "    "        "          "
  Seconds          "      "   6      "    "        "          "
  L. F. X.         "      "  20      "    "        "          "
  C. L. F. X.      "      "  27      "    "        "          "
  C. C. L. F. X.   "      "  30      "    "        "          "
  F. F.            "      "  15      "    "        "          "

These are all boiled at a pressure of from 20 to 25 lbs. for 10
hours, in stationary boilers without vomit, and also in boilers
revolving horizontally. In some mills, where the best qualities of
paper are made, iron boilers are objected to, as small particles
of oxide of iron are apt to become dislodged from the interior of
the boiler, and produce discolouration of the paper. In such cases
wooden vats, with mechanical stirrers, are employed; sometimes a
jacketed boiler is used.


[Illustration: Figs. 11 and 12.]

=Washing and Breaking.=--The removal of the dirty water resulting
from the boiling is effected in the washing and breaking engine, or
"rag engine," as it is commonly called, which is constructed on the
same principle as the beating engine, but is provided with an extra
drum, called the _drum-washer_, which, being covered with wire
gauze, allows the washing waters to escape without permitting the
fibrous stuff to pass through. The rag engine, having been invented
by a Dutchman, acquired, and still retains, the name of the
_Hollander_, and although it has been considerably improved upon,
its principle is still retained in the modern engines, of which
there are many different forms. The ordinary rag engine, Figs. 11
and 12, consists of a cast-iron trough A, about 10 feet long, 4½
feet wide, and 2½ feet deep, and rounded at the ends, and is firmly
bolted to a wooden foundation. It is provided with a partition
termed the _midfeather_ B, of such a length as to have the trough
of uniform width round it. A cylinder, or _roll_, C, furnished with
a series of steel knives, rotates in one of the divisions formed
by the midfeather, and the floor of the trough in this division is
inclined in such a manner as to cause the pulp, as it travels, to
pass under the roll. Beneath the roll is the _bed-plate_, which
is fitted with a series of steel knives _c c_ similar to those on
the exterior of the roll. The distance between the knives of the
roll and the bed-plate is regulated by levelling screws, which
are so adjusted that both ends of the roll are raised at the same
time, which is a great improvement upon the older types of breaking
engines in which only one end of the roll was raised, whereby the
knives became unequally worn. By the present method of regulating
the distance between the respective sets of knives, any required
degree of fineness can be given to the fibrous substances treated.
The roll is generally caused to rotate at a speed of about 230
revolutions per minute, causing the water and rags to circulate in
the engine and to be constantly under the action of the knives. In
the other division F F of the trough is the drum-washer H, which,
being covered with fine gauze wire, allows the water to enter, but
keeps back the fibrous material. The ends of the drum are formed
of two discs of wood, generally mahogany, upon which the coarse
gauze is fastened as a backing, and this is covered with the fine
wire gauze. The interior of the drum is sometimes furnished with a
series of buckets, which conduct the water to a trough in the axis
of the drum, by which it is led away. This is also accomplished by
dividing the interior of the cylinder into compartments by means of
a partition. The drum-washer is so arranged that it can be wholly
raised out of the trough, which is necessary in certain parts of
the operation, when the removal of the liquid is not required; or
it can be partially raised, or otherwise, according to requirement.
The floor of the compartment containing the roll C is inclined at
D, so as to cause the pulp to pass directly under the roll, and at
D′ is the _backfall_, over which the pulp travels to the opposite
side of the midfeather.

In working the rag engine, it is first partly filled with water,
and then set in motion; the boiled stuff is then gradually put
in, and a constant supply of clean water is run in from a cistern
provided with means of preventing sand or other impurities from
finding their way into the engine. It is of the utmost importance
that the water should be abundant and of good quality, more
especially as the material (rags) is mostly required for making
the finer qualities of paper. In this respect the county of Kent
and a few other localities on the chalk formation are considered
specially suitable for this particular manufacture.

With respect to the driving of the engines, this was formerly
effected by what is called _toothed gearing_, but cog-wheels were
afterwards replaced by iron spur-wheel gearing, which enabled
manufacturers to drive four or more engines from one source of
power, by continuing the line of shafting and spur-wheels; but even
with small rolls the wear and tear on this system was considerable,
while it was quite inadequate to the driving of a number of
large rolls of 30 inches in diameter, such as are now used. The
introduction of belt-gearing, by Messrs. G. and W. Bertram, proved
to be a great improvement on the older system, and it is found that
the rags are broken not only more uniformly, but in less time, as
the rolls work more steadily on the plates than with any system of
wheel-gearing, while the various working parts of the engine last
longer than when subjected to the vibrating action of wheel-gearing.


[Illustration: Fig. 13.]

=Bertrams' Rag Engine.=--This engine, of which a drawing is shown
in Fig. 13, may be used either as a washing and breaking engine,
potcher, or beater. It is provided with double lifting gear, and
has "all sweeps, curves, and angles" of the most improved design
to save lodgments and ensure steady and thorough travelling of
the pulp. The drum-washer is shown lifted by rack and pinion and
worm gear, and empties down the midfeather direct to mouthpiece.
The emptying can be done by spout and pipe, or by a chamber cast
on the engine, down back or front side, as well as through the
midfeather; but it is not advisable that it should be emptied down
the midfeather if the rag engine is to be used as a beater.


[Illustration: Fig. 14.]

=Bentley and Jackson's Rag Engine.=--This form of engine is shown
in Fig. 14. The trough is of cast-iron, and made whole, and the
engine can be obtained of any required dimensions. The trough is
provided with a sand-well, cast-iron grate, and cock in front of
the roll, and a sand-well, cast-iron grate, and brass valve on
the back of the midfeather, a brass let-off valve and a brass
waste-water valve. The bottom of the trough is "dished," to prevent
the stuff from lodging. There are two movable bridge trees, fitted
with pedestals and brass steps, and wrought-iron lifting links
and screws, worm-wheels, worms, cross-shaft and hand-wheel for
simultaneously lifting the roll on both sides. The roll is covered
by a polished pitch-pine cover. The drum-washer may have either
iron or wooden ends, has strong copper brackets, and is covered
with brass backing and covering wires, mounted on a wrought-iron
shaft, and carried by cast-iron stands, fitted with improved
lifting gear, driving-wheels, and pulley.

When the engine is set in motion by the revolving shaft or spindle,
the combined action of the knives of the roll and bed-plate causes
the rags, which circulate in the water, to be gradually cut into
small fragments, and the operation is kept up until the rags are
converted into what is technically termed _half-stuff_. While
this process is going on, fresh water is constantly supplied by a
pipe at the end of the washing-engine; and when it is found that
nothing but clear water escapes from the drum-washer, this is
raised, and the spindle bearing the roll is lowered, so as to bring
the respective knives closer together, to enable them to cut the
reduced material still finer.


=Draining.=--When the material is sufficiently _broken_, as it is
termed, the engine is then emptied by means of its valves, and
the contents run into large vats or _drainers_, furnished with
perforated zinc floors, in which it is allowed to drain thoroughly;
and in order to remove the water more effectually, the pulp is
afterwards pressed, either by an extractor or a centrifugal
drainer, which dries it sufficiently for gas-bleaching, or for
treatment in the _potcher_ or _poacher_. This is a larger engine
than the washer, and instead of the cylinder and bars, has a
hollow drum which carries on its periphery a number of cast-iron
paddles, which thoroughly agitate the pulp, and thus render it
more susceptible of being freely and uniformly acted upon by the
bleaching agent. The drum-washer of this engine should have a finer
wire than is used for the breaker.


=Torrance's Drainer.=--This machine, which has been extensively
used, is manufactured by Messrs. J. Bertram and Son, of Edinburgh.
It consists of a perforated cylindrical box, enclosed in a fixed
case, which revolves at about two hundred and fifty revolutions per
minute. The machine is capable of treating about 4 cwt. of pulp per
hour.



CHAPTER V.

_TREATMENT OF ESPARTO._

  Preliminary Treatment.--Picking.--Willowing Esparto.--Boiling
  Esparto.--Sinclair's Esparto Boiler.--Roeckner's
  Boiler.--Mallary's Process.--Carbonell's Process.--Washing Boiled
  Esparto.--Young's Process.--Bleaching the Esparto.


=Preliminary Treatment: Picking.=--Esparto is imported in bales or
trusses, tightly compressed by hydraulic presses, and bound with
twisted bands of the same material, much in the same manner as hay,
except that which comes from Tripoli, which is bound with iron
bands. The bands being cut, the loosened material is then spread
out upon tables, partly covered with iron, or galvanised-iron,
netting, to allow earthy matter or sand to pass through to a
receptacle beneath. Here it is carefully picked by women and girls,
who remove all roots, other kinds of grass, weeds, and heather.
The material thus cleansed from impurities is transferred to the
boiling-room. This careful preliminary treatment has been found
necessary, since pieces of root and other vegetable matters which
may be present are liable to resist the action of the bleaching
liquor to a greater extent than the grass itself, and therefore
produce specks, or "sheave" as they are termed at the mill, in the
manufactured paper.

At some mills, however, as at the Horton Kirby Mills of Messrs.
Spalding and Hodge, at South Darenth, for example, the cleaning
of esparto is admirably effected by means of a willow, or
esparto-cleaner, constructed by Messrs. Masson, Scott, and
Bertram, which entirely supersedes the system of hand-picking.
Having recently visited the mill referred to, we were enabled,
through the courtesy of Mr. Sydney Spalding, to witness the
action of this willow, which appeared to perform its functions
with perfect uniformity, and to clean the grass most effectually.
The _rationale_ of the operation of willowing esparto may be thus
described:--


=Willowing Esparto.=--A bale of the grass is unbound at a short
distance from the machine, and the grass, which is in the form of
small bundles or sheaves, tied with bands of the same material,
is thrown by a woman on to a table or platform placed by the side
of the willow, and a second woman, standing near the hopper of
the machine, takes the bundles, a few at a time, and drops them
into the hopper. The machine being in motion, in a few moments
the grass, freed from its bands and dirty matters, appears in a
perfectly loose condition at the wider end of the drum, and passes
upward along a travelling-table to a room above, in the floor of
which are the man-holes of a series of esparto boilers. During the
passage of the loosened fibre, women standing on steps or platforms
at the sides of the travelling-table are enabled to examine the
material, and to remove any objectionable matters that may be
present. Beneath the drum of the machine is a pipe, through which
the dust and dirty matters are drawn away by means of a fan.


=Boiling Esparto.=--In the boiling-room at the mill referred to
is a series of vertical stationary boilers, each about twenty
feet high, and capable of holding about three tons of grass. The
man-holes of these boilers pass through the floor of a room above,
being nearly level with it, into which the cleaned esparto is
conveyed, as described, by the travelling-table of the willowing
machine. In this room is a series of compartments in which the
willowed esparto is stored until required for boiling, when it is
fed into the boilers by means of two-pronged forks provided for the
purpose. The boiler being partially charged with caustic ley at
14° Twad., the esparto is introduced, and steam also, by which the
esparto becomes softened, and thus a larger quantity of the fibre
can be charged into the vessel. When the full charge of ley and
esparto have been introduced the head of the boiler is securely
fixed by means of its bolts, and steam then turned on until a
pressure of about 20 lbs. to the square inch has been reached,
which pressure is kept up for about three hours, when the steam
is shut off and the blow-off tap opened. When the steam is blown
off, the spent liquor is run off, and hot water then run into the
boiler, steam again turned on, and the boiling kept up for about
twenty minutes to half an hour, at the end of which time the steam
is shut off and the blow-pipe opened. As soon as the steam has
blown off, the washing water is run off by the bottom pipe, and the
grass allowed to drain as thoroughly as possible. A door at the
lower end of the boiler is then opened, and the grass emptied into
trucks and conveyed to the washing-engines.


[Illustration: Fig. 15.]

[Illustration: Fig. 16.]

=Sinclair's Esparto Boiler.=--Another form of boiler, known as
Sinclair's boiler, of the vertical cylindrical type, is shown in
Figs. 15 and 16. It is constructed on what is termed the "vomiting"
principle, but without the central vomiting-pipes generally used,
and is fitted with one or more vomiting-pipes close to the side,
two diametrically opposite pipes being used by preference. Steam
jet pipes, with upwardly-directed nozzles, are fitted into the
vomiting-pipes at points a little above the bends, between the
vertical and horizontal parts. The liquid or ley thrown up the
vomiting-pipes by the action of the steam is delivered from the
upper ends of the pipes over a diaphragm or plate fixed near the
top of the boiler, and the liquid is retained at a certain depth
on the diaphragm by a number of small tubes fixed in it, and the
liquid becomes well heated by the steam before overflowing down
the tubes, which tubes also serve to distribute it uniformly
over the fibrous materials in the boiler. A casing is formed at
the bottom of the boiler, and in some cases extended more or
less up the sides, and is supplied with steam, which should be
superheated, or of high pressure. With this arrangement the heat
in the boiler is maintained without the excessive condensation of
steam and consequent dilution and weakening of the liquors which
occurs in ordinary boilers. Figs. 15 and 16 are horizontal and
vertical sections of one form of this boiler. The boiler is made
with a vertical cylindrical shell, 1; with a flat top, 2; and
flat bottom, 3; and there is an inner or second bottom, 4; the
space between it and the bottom, 3, being for steam to assist in
heating the contents of the boiler. At a little distance above
the inner bottom, 4, there is the usual perforated horizontal
diaphragm, 5, down through which the liquid or ley drains from
the fibre. Two diametrically opposite vertical vomiting-pipes, 6,
are formed by the attachment of curved plates to the cylindrical
shell, 1, and these vomiting-pipes, 6, have their upper ends above
a horizontal diaphragm, 7, attached by stays to the boiler top,
2. This diaphragm is perforated, and short tubes, 8, are fixed in
the perforations so as to project upwards, by which arrangement
the liquid, rising up the vomiting-pipes, 6, lies on the diaphragm
to the depth of the tubes, 8, and overflows down through them all
equally, so as to be uniformly distributed over the materials in
the boiler. Steam jet nozzles, 9, are fitted in the lower parts of
the vomiting-pipes, being supplied with steam by pipes, 10, from
one of which a branch, 11, supplies steam to the double bottom,
3, 4. The steam jets cause the liquid to be drawn from under the
perforated diaphragm, 5, and thrown up the pipes, 6, whereby a
constant circulation of the liquid through the fibre is maintained.
The liquors are drawn off by the pipe, 15. In another form of
boiler Mr. Sinclair employs vomit-pipes formed of thin steel
plates riveted to opposite sides of the boiler, and the liquid
which drains through the perforated double bottom is forced upward
through the vomit-pipes to the perforated plates above, through
which it distributes over the material in fine jets. The boiler
is capable of holding from 2 to 3 tons of esparto, and under a
pressure of from 40 to 50 lbs. the boiling occupies about two hours.


[Illustration: Fig. 17.]

=Roeckner's Boiler.=--This boiler, of which an illustration of
two in series is given in Fig. 17, has been extensively adopted
by paper manufacturers. It will be noticed that the vomit-pipe A
is placed outside the boiler, and the steam enters at the cock B,
forcing the liquor up the vomit-pipe A and distributing it over
the esparto. A pipe C is used for heating the liquor by means of
waste steam at the commencement of the operation. The grass is fed
into the boiler at the opening D. At E E are gauges for showing
the height of the liquor in the boiler, F F F are pipes for the
supply of steam, strong ley, and water, and the door G is for the
discharge of the boiled grass. Each boiler is capable of holding 3
tons of esparto, and the boiling is completed in about two and a
half hours, at a pressure of from 35 to 40 lbs. per square inch.
It is said that the boiler effects a saving both in time and the
amount of soda used.


=Mallary's Process.=--By this process the inventor says that he
obtains the fibre in greater length, and gets rid of the gummy
and resinous matters in a more economical way than by the present
system. The materials used form a species of soap, with which and
with the addition of water, the esparto is boiled. To carry out his
process, he places in a boiler a suitable quantity of water, to
which caustic soda, or a ley of the required strength to suit the
nature of the fibre, is added; magnesite, or carbonate of magnesia,
in the proportion of about 2 per cent. of the fibrous material, or
a solution of sulphate of magnesia, is then added and mixed with
the ley. He next adds "an improved saponaceous compound" to produce
the required result, and when the boiling is completed, the stuff
is treated as ordinary stock, to be applied for paper-making or
other uses. The proportions are as follows:--2 gallons of petroleum
or its products, 1 gallon of mustard oil, 10 to 15 lbs. of caustic
soda, and 1 per cent. of boracic acid. These are placed in a copper
and heated for 1 to 2 hours, until properly saponified. From 3 to
6 gallons of the "saponaceous compound" are added to the ley and
magnesite, previously placed in the boiler with the fibre, and the
boiling is kept up for the usual length of time, when the fibre
will be found "beautifully soft, and the greater portion of the
gum, silica, and resinous matters removed, or so softened as to
be no hindrance to the perfect separation of the fibres, whilst
the strength, silkiness, and softness are preserved in all their
natural integrity." Considering that caustic soda ley "of the
required strength" forms an essential part of this process, we
should imagine that the auxiliaries mentioned would scarcely be
necessary.


=Carbonell's Process.=--In this process, devised by M. Carbonell,
of Paris, 200 lbs. of raw esparto are placed in a wooden vat
furnished with a perforated steam-pipe, 20 lbs. of soda and 30
lbs. of quicklime being mixed with it: the vat is then supplied
with cold water until the esparto is completely covered. Steam is
then turned on, and the materials boiled for 4 hours. The spent
liquor is then drained off, and the esparto submitted to hydraulic
pressure. It is afterwards washed and broken in a rag engine, and
in about 15 minutes is reduced to half-stuff. 20 lbs. of chloride
of lime dissolved in water are then introduced, and the cylinder
kept in motion as usual. In another vessel, lined with lead, 1¼
lb. of sulphuric acid is dissolved in 3 lbs. of water, and this
gradually added to the pulp, which immediately assumes a reddish
colour; but in the course of about three quarters of an hour it
becomes perfectly white, when the pulp is ready for the paper-maker.

In the boiling of esparto, several important points have to
be considered. The kind of esparto to be treated is the first
consideration, since this grass differs materially in character in
the different countries from which it is imported. Spanish esparto
is considered the best for paper-making, as it is stronger in
fibre and yields a whiter pulp than other varieties. Of the African
espartos there are several varieties, which are known respectively
as Oran, Tripoli, Sfax, Gabes, and Susa. Of these, the first-named
(Algerian esparto) is held in highest estimation amongst
paper-makers, since it more closely resembles Spanish esparto than
the other varieties, though not so hard and stiff as the latter.
These grasses usually have a length of about 10 to 12 inches.
Tripoli esparto has an entirely different growth, being sometimes
as long as 2½ or 3 feet, and proportionately stouter, and is also
softer than Oran esparto, which is not so hard as the Spanish
variety. Tripoli esparto does not yield a strong paper by itself,
but in conjunction with Oran esparto gives more favourable results.
Sfax and Gabes espartos have a closer resemblance to Oran than
Tripoli, but are not so strong as Oran, being green and spongy, and
not so dry as the latter variety. Susa esparto of good quality is
said to equal Oran, but not to yield so high a percentage of fibre.

The next important consideration is to determine the percentage
of caustic alkali which should be used per hundredweight of the
particular variety of esparto to be treated, and we cannot do
better than give the following proportions recommended by Mr.
Dunbar.

  Fine Spanish   18 to 20 lbs. of 70 per cent. caustic soda per cwt.
  Medium Spanish 16 to 18      "         "           "          "
  Fine Oran            18      "         "           "          "
  Medium Oran    16 to 17      "         "           "          "
  Susa                 18      "         "           "          "
  Tripoli        19 to 20      "         "           "          "
  Sfax           20 to 21      "         "           "          "

Mr. Dunbar says that the above figures "insure a first-class boil,
with the steam pressure of 25 lbs. and not exceeding 30 lbs., but
are liable to alteration according to circumstances--such as the
form of boilers, quality of the water for boiling purposes, and
steam facilities, which ought at all times to be steady and uniform
to get the absolute regularity required."

Respecting the strength of caustic ley used for boiling esparto, as
indicated by Twaddell's hydrometer, this appears to range from 7°
to 15°, some preferring to boil with stronger liquors than others.
The time occupied in boiling also varies at different mills, and
depends greatly upon the character of the boiler used. We are
informed that a Sinclair boiler will turn out, on an average,
three boils in twenty-four hours, including filling, boiling,
discharging, &c., the boiling occupying about four hours for each
batch of grass.

The boiling being completed, the liquor is run off into tanks, to
be afterwards treated for the recovery of the soda, and the esparto
is then subjected to a second boiling with water only for about 20
minutes. The liquor from the second boiling is sometimes thrown
away, even when the soda from the first liquor is recovered; but
a more economical method is to use this liquor, in lieu of water,
strengthened with soda for a first boiling; or to mix it with the
first liquors and evaporate the whole together. The second boiling
being finished, the steam is turned off, and water then run in and
steam again turned on for a short time, and the water then run off
and the esparto allowed to drain thoroughly. The boiled grass is
then discharged into trucks which convey it to the washing engines.

The liquor resulting from the boiling of esparto, which is of a
dark brown colour, contains nearly all the soda originally used,
but it also contains silicious, resinous, and other vegetable
matters which it has dissolved out of the grass, the silica
taking the form of silicate of soda. The esparto liquor, which
was formerly allowed to run to waste, polluting our rivers to a
serious extent, is now treated by several ingenious methods for
the recovery of the soda with considerable advantage alike to the
manufacturer and the public. The process consists essentially
in boiling down the liquor to dryness, and incinerating the
residue. During the process of incineration the carbonaceous
matter extracted from the grass is converted into carbonic acid,
which, combining with the soda, reconverts it into carbonate of
soda, which is afterwards causticised with lime in the usual way,
and the caustic soda thus obtained is again used in the boiling
of esparto. Although one or other of the "recovery" processes is
adopted at a good many of our paper-mills, the recovery of the
soda is by no means universal as yet, but the time will doubtless
soon arrive when the economical advantages of the process will
be fully recognised. Indeed, we know it to be the fact that some
manufacturers are watching, with keen interest, the progress of
some of the newer systems of soda recovery, with the full intention
eventually of adopting one or other of them.


=Washing Boiled Esparto.=--This operation is usually performed in
engines similar to those used in washing rags, but in some mills
the boiled grass is washed in a series of tanks, so arranged
that water flows in at one end of the series, thence passing
in succession through each batch of grass in the other tanks,
and finally issues at the farthest end of the series as a very
concentrated liquor. By this arrangement there is great economy
of water, while at the same time no loss of fibre occurs. The
concentrated washing liquors thus obtained may be evaporated,
and the alkali recovered, which would be an undoubted saving,
since these liquors obtained in the ordinary way by washing in
the boilers are generally run off as waste. The engines used for
washing esparto and converting it into half-stuff are generally of
large size, and capable of treating a ton of boiled esparto. In
this engine, however, there is no bed-plate, as the action of the
roll alone is sufficient to reduce the boiled and softened esparto
to half-stuff. A drum-washer is also furnished to the engine, which
carries off the dirty washing water, while an equivalent proportion
of clean water is kept constantly running into the engine from
an elbowed pipe at its end. In charging the washing-engine, it
is first about three parts filled with water, when the washing
cylinder is lowered, and the esparto is then put in, care being
taken not to introduce more of the material than will work freely
under the action of the roll; if the mass be too stiff, portions
of the material may be imperfectly washed. While the washing is in
progress, the workman, armed with a wooden paddle, constantly stirs
the esparto, clearing it away from the sides of the engine, so that
none of the material may escape a perfect washing. At the bottom of
the engine is a "sand-trap," covered with perforated zinc, through
which any sand or other solid particles which may be present
escape. When the washing is complete, the fresh water supply is
shut off, and the drum-washer allowed to run until enough water has
been removed to make room for the bleaching liquor.


=Young's Process.=--By this process the boiled and strained esparto
is passed through elastic covered rollers, so adjusted as to split
up and squeeze out the dissolved matters or liquid from the fibres,
thus leaving them clean and open for the access of the bleaching
liquor.


=Bleaching the Esparto.=--It is usual to bleach esparto in the
washing engine, for which purpose a tank of bleaching liquor of
the required strength (about 6° T. for Spanish) is placed close to
the engine, which is provided with a pipe leading to the engine
and another pipe proceeding from the tank in which the bleaching
liquor is stored. The supply tank is furnished inside with a gauge,
divided into inches--each inch representing so many gallons of
liquor--by means of which the workman is enabled to regulate the
quantity of bleaching liquor he is instructed by the manager or
foreman to introduce into the engine. About half an hour after
the bleach has become well incorporated with the fibre, sulphuric
acid in the proportion of six ounces of the acid (which must be
well diluted with water) to each hundredweight of the fibre.
The dilute acid should be added gradually, and the proportions
given must not be exceeded. The bleaching being completed, the
half-stuff is next treated in a machine termed the _presse-pâte_,
which not only cleanses the material from sand and dirt, but also
separates all knots and other imperfections from the fibre in a
most effectual and economical manner. Indeed, we were much struck
with the excellent working of this machine at Messrs. Spalding and
Hodge's mill, at South Darenth, and the remarkably fine quality
of the finished pulp obtained through its agency. The presse-pâte
was formerly used in the preparation of pulp from straw, but its
advantages in the treatment of esparto are now fully recognised.
The apparatus and method of working it may be thus briefly
described:--

The machine is on the principle of the _wet end_ of a paper
machine, and consists of several stone chests for holding the
bleached half-stuff, in which are fitted agitators to keep the
stuff in suitable condition. From these chests the stuff is pumped
into a mixing box, and from thence over a series of sand traps made
of wood, and with slips of wood fixed in the bottom, in which any
sand present is retained. The stuff then passes into a series of
strainers, which, while allowing the clean fibre to pass through,
retain all impurities, such as knots, &c., and the clean stuff is
allowed to flow on to the wire-cloth in such a quantity as to form
a thick web of pulp. A greater portion of the water escapes through
the wire-cloth, but a further portion is removed by the passage
of the pulp across two vacuum boxes, connected with four powerful
vacuum pumps, which renders the half-stuff sufficiently dry to
handle; but to render it still more so, it now passes between couch
rolls, and is either run into webs, or, as is sometimes the case,
it is discharged into boxes, the web of pulp thus treated being
about an inch in thickness.



CHAPTER VI.

_TREATMENT OF WOOD._

  Chemical Processes.--Watt and Burgess's Process.--Sinclair's
  Process.--Keegan's Process.--American Wood Pulp
  System.--Aussedat's Process.--Acid Treatment of Wood.--Pictet
  and Brélaz's Process.--Barre and Blondel's Process.--Poncharac's
  Process.--Young and Pettigrew's Process.--Fridet and Matussière's
  Process.


The advantages of wood fibre as a paper material have been fully
recognised in the United States and in many Continental countries,
but more especially in Norway, Sweden, and Germany, from whence
large quantities of wood pulp are imported into this country. There
is no doubt that our home manufacturers have recently paid much
attention to this material, and it is highly probable that wood, as
an inexhaustible source of useful fibre, will at no distant date
hold a foremost rank. Indeed, the very numerous processes which
have been patented since the Watt process was first made known,
indicate that from this unlimited source of fibre the requirements
of the paper-maker may be to a large extent satisfied, provided, of
course, that the processes for reducing the various suitable woods
to the condition of pulp can be economically and satisfactorily
effected. The great attention which this material has received at
the hands of the experimentalist and chemist--the terms not being
always synonymous--shows that the field is considered an important
one, as indeed it is, and if successfully explored will, it is to
be hoped, yield commensurate advantages both to inventors and the
trade.

The object of the numerous inventors who have devised processes
for the disintegration of wood fibre--that is, the separation of
cellulose from the intercellular matters in which the fibres are
enveloped--has necessarily been to dissolve out the latter without
injury to the cellulose itself, but it may be said that as yet the
object has not been fully attained by either of the processes which
have been introduced. To remove the cellular matter from the true
fibre or cellulose, without degrading or sacrificing a portion of
the latter, is by no means easy of accomplishment when practised
on an extensive scale, and many processes which present apparent
advantages in one direction are often found to exhibit contrary
results in another. The field, however, is still an open one, and
human ingenuity may yet discover methods of separating wood fibre
from its surrounding tissues in a still more perfect manner than
hitherto.

The various processes for treating wood for the extraction of its
fibre have been classified into: (1) chemical processes; and (2)
mechanical processes. We will give precedence to the former in
describing the various wood pulp processes, since the pulp produced
by the latter, although extensively used, is chiefly employed,
in combination with other pulps, for common kinds of paper. In
reference to this part of our subject Davis says:--"Experience
has dictated certain improvements in some of the details of
those earlier methods, by which so-called 'chemical wood pulp'
is manufactured very largely on the Continent of Europe.... It
is possible to obtain a pulp of good quality, suitable for some
classes of paper, by boiling the chipped wood in caustic soda, but
when it is desired to use the pulp so prepared for papers having a
perfectly white colour it has been demonstrated in practice that
the action of the caustic soda solution at the high temperature
which is required develops results to a certain degree in weakening
and browning the fibres, and during the past five years much labour
has been expended in the endeavour to overcome the objections
named. The outcome of these efforts has been a number of patents,
having for their object to prevent oxidation and subsequent
weakening of the fibres." In several of these patents, to which we
shall refer hereafter, bisulphite of lime is employed as the agent
to prevent oxidation and consequent degradation of the fibres, and
in other processes bisulphite of magnesia has been used for the
same purpose. Davis further remarks: "Although a common principle
runs through all these methods of preparing cellulose from wood,
they differ in detail, as in the construction of the digesters
employed, methods of treating the wood stock before boiling it in
the sulphurous acid solution, and also as regards pressure, blowing
off the sulphurous acid gas, etc., but all these processes present
a striking similarity to the method patented by Tilghmann in 1867."
There can be no doubt that the action of caustic soda, under high
pressures, is highly injurious both to the colour and strength of
the fibres, and any process that will check this destructive action
in a thoroughly practical way will effect an important desideratum.


=I. Chemical Processes=: _Watt and Burgess's Process_.--This
process, which, with some modifications, is extensively worked
in America, consists in boiling wood shavings, or other similar
vegetable matter, in caustic soda ley, and then washing to remove
the alkali; the wood is next treated with chlorine gas, or an
oxygeneous compound of chlorine, in a suitable vessel, and it is
afterwards washed to free it from the hydrochloric acid formed. It
is now treated with a small quantity of caustic soda in solution,
which instantly converts it into pulp, which only requires to
be washed and bleached, and beaten for an hour and a half in
the beating engine, when the pulp is ready for the machine. The
wood-paper process as carried out in America has been described by
Hofmann, from whose work[15] we have abridged the following:--

The wood, mostly poplar, is brought to the works in 5-feet lengths.
The bark having been stripped off by hand, it is cut into ½-inch
slices by a cutter which consists of four steel knives, from 8
to 10 inches wide by 12 to 15 inches long, which are fastened in
a slightly inclined position to a solid cast-iron disc of about
5 to 7 feet diameter, which revolves at a high speed, chopping
the wood--which is fed to the blades through a trough--into thin
slices across the grain. The trough must be large enough to receive
the logs, usually 10 or 12 inches thick, and it is set at such an
angle that the logs may slide down towards the revolving cutters;
this slanting position only assists the movement of the logs,
while a piston, which is propelled by a rack, pushes them steadily
forward until they are entirely cut up. The piston, or _pusher_,
then returns to its original position, fresh wood is put into the
trough, and the operation repeated. In this way many tons of wood
can be chopped up by one of these cutters in a day. The sliced wood
is conveyed by trucks to an elevator by which it is hoisted up two
storeys to a floor from which the boilers are filled. The boilers
are upright cylinders, about 5 feet in diameter and 16 feet high,
with semi-spherical ends, provided inside with straight perforated
diaphragms, between which the chips from one cord of wood are
confined. A solution of caustic soda, at 12° B., is introduced with
the chips, and fires are started in a furnace underneath. At other
works the boilers are heated by steam circulating through a jacket
which covers the bottom and sides of the boiler.

The boiling is continued for about six hours, when the digestion
is complete, and the contents of the boilers are emptied with
violence, under the pressure of at least 65 lbs. of steam, which
had been maintained inside. A large slide valve is attached to
the side of each boiler for this purpose close to the perforated
diaphragm, and connected by a capacious pipe with a sheet-iron
cylinder of about 12 feet diameter and 10 feet high, which receives
the contents--pulp, liquor, and steam. The object of these large
chambers--one of which serves for two boilers--is to break the
force of the discharging mass. The steam passes through a pipe on
the top of each, and from thence through a water reservoir, while
the liquid containing the pulp flows through a side opening and
short pipe into movable boxes, or drainers, mounted on wheels, and
each capable of holding the contents of one boiler; these boxes are
pushed along a tramway up to the collecting chambers, where the
pulp is received. In a building 132 feet long and 75 feet wide, ten
digesting boilers are arranged in one straight line, and parallel
with the boilers runs the main line of rails, side tracks extending
from it to each of the chambers, and a turn-table is supplied at
every junction. By this arrangement the drainer waggons can be
pushed from the side tracks on to the main line, which leads to
the washing-engines in an adjoining room. A system of drainage
is established below the tramways, by which all the liquid which
drains from the waggons is carried away and collected for treatment
by evaporation; these carriers remain on the side tracks until the
pulp is ready for the washing-engine.

When the greater portion of the liquor has drained off, warm
water is sprinkled over the pulp from a hose for the purpose of
extracting all the liquid which is sufficiently concentrated
to repay the cost of evaporation--the most advantageous method
of recovering the soda. The contents of the waggons--from the
same number of boilers--are then placed in two washing-engines,
each capable of holding 1,000 lbs. of pulp. After being
sufficiently worked in these engines the pulp is transferred
to two stuff-chests, and from thence conveyed by pumps to two
wet-machines. The screens (strainers) of the wet-machines retain
all impurities derived from knots, bark, and other sources, and the
pulp, or half-stuff, obtained is perfectly clean and of a light
grey colour. The pulp is bleached with solution of bleaching powder
like rags, then emptied into drainers and allowed to remain therein
with the liquid for twenty-four to forty-eight hours, or long
enough to render the use of vitriol in the bleaching unnecessary.
The portion of the white pulp which is to be worked up into paper
in the adjoining mill is taken from the drainers into boxes
running on tramways in the moist state, but all the pulp which has
to be shipped to a distance is made into rolls on a large cylinder
paper-machine with many dryers. The object being merely to dry the
pulp, a very heavy web can be obtained, since the water leaves this
pulp very freely. The wood pulp thus obtained is perfectly clean,
of a soft, white spongy fibre, and a greater portion of it is mixed
with a small proportion of rag pulp and worked into book and fine
printing papers. Sometimes the wood pulp is used alone or mixed
with white paper shavings for book paper. The fibres are rather
deficient in strength, but as a material for blotting paper they
are said to be unsurpassed, while the wood paper is much liked by
printers.

The wood from poplar, which is generally preferred, furnishes a
very white fibre, and is easily digested, but since the fibres are
short it is sometimes found advantageous to mix them with longer
fibres, as those of the spruce or pine, although the latter wood
requires a much more severe treatment in boiling with alkali than
the former. In reference to this process the following remarks
appeared in _The Chemist_,[16] 1855:--"The process occupies only
a few hours; in fact, a piece of wood may be converted into
paper and printed upon within twenty-four hours." An interesting
verification of this was published a few years since in an American
paper, the _Southern Trade Gazette_, of Kentucky, which runs as
follows:--"At a wood-pulp mill at Augusta, Ga., a tree was cut
down in the forest at six o'clock A.M., was made into pulp, and
then into paper, at six o'clock in the evening, and distributed
amongst the people as a newspaper by six o'clock the next morning.
From a tree to a newspaper, being read by thousands, in the brief
round of twenty-four hours!" The wood-paper process referred to has
given rise to many subsequent modifications, some of which we will
briefly describe.


=Sinclair's Process.=--The wood is first cut into pieces about
1 inch broad, ⅛th inch thick, and from 2 to 3 inches long. It is
then placed in a boiler and a solution of caustic soda, in the
proportions of 600 gallons to 10 cwts. of dry wood, is poured over
it. The boiler having been securely closed, the heat is raised
till a pressure of 180 to 200 lbs. on the square inch is obtained,
when the fire is withdrawn and the boiler allowed to cool, after
which the ley is blown off, the top door removed, and the contents
scalded. The discharge door is now opened and the pulp transferred
to a poaching-engine to be washed with pure water, when the resin,
&c., are easily removed and the clean fibres obtained, which, it is
said, are longer and firmer than those obtained by other methods.


=Keegan's Process.=--By this method soft deal or pine is sawn up
into pieces from 6 to 12 inches long and ½ inch thick, it being
preferable that all the pieces should be of an equal size, but the
smaller they are the more rapid, of course, will be the operation.
The pieces of timber are placed in a cylindrical boiler, turning
upon a horizontal axis while the digestion is progressing. In a
second boiler is prepared a solution of caustic soda of about 20°
B. (specific gravity 1·161), which is introduced through a pipe
into the first boiler, this being afterwards hermetically closed,
and the soda is forced into the pores of the wood by means of a
pump. When the wood is not more than half an inch in thickness
a pressure of 50 lbs. on the square inch is sufficient, and the
injection of the caustic soda solution is completed in half an
hour. The superabundant liquor is pumped back into the second
boiler for the next operation. The excess of liquor having been
removed from the wood as stated, steam is introduced between the
double sides of the first boiler, and the temperature of the wood
raised from 150° to 190° C. (334° to 438° F.). The wood is next
washed in the usual way until the liquor runs off perfectly limpid,
and the half-stuff thus produced may be converted into pulp either
before or after bleaching, according to the quality and colour of
the paper to be produced.


=American Wood-Pulp System.=--Another method of carrying out the
wood-pulp process has recently been described by Mr. E. A. Congdon,
Ph.B.,[17] from which we extract the following:--"Poplar, pine,
spruce, and occasionally birch, are used in the manufacture of
chemical fibre. Pine and spruce give a longer and tougher fibre
than poplar and birch, but are somewhat harder to treat, requiring
more soda and bleach. Sticks of poplar, freed from bark, and
cleansed from incrusting matter and dirt, are reduced to chips by a
special machine having a heavy iron revolving disc set with knives,
and are then blown by means of a Sturtevant blower into large
stove chambers after passing over a set of sieves having 1¼-inch
for the coarse and 1⅛-inch mesh for the fine sieves, from whence
they pass to the digesters, which are upright boilers 7 by 27
feet, with a manhole at the top for charging the chips and liquor,
and a blow-valve at the bottom for the exit of the boiled wood. A
steam-pipe enters at the bottom, beneath a perforated diaphragm,
and keeps the liquor in perfect circulation during the boiling of
the wood by means of a steam-ejector of special construction."

_Boiling._--The average charge of wood for each digester is 4·33
cords,[18] giving an average yield of 4,140 lbs. of finished fibre
per digester. A charge of 3,400 gallons of caustic soda solution
of 11° B. is given to each digester charged with chips, and the
manhead is then placed in position and steam turned on. Charging
the digester occupies from thirty to forty-five minutes, and steam
is introduced until the gauge indicates a pressure of 110 lbs.,
which occupies about three hours. This pressure is kept up for
seven hours, when it is reduced by allowing the steam to escape
into a large iron tank which acts as a separating chamber for the
spent liquor it carries, the steam entering in at one end and
passing out at the other through a large pipe, the liquor remaining
in the tank. The steam is allowed to escape until the pressure
is reduced to 45 lbs., when the digester is blown. The blow-cap
being removed, the blow-valve is raised and the contents of the
digester are discharged into a pan of iron covered with a suitable
hood. The contents strike against a dash-plate placed midway in
the pan, which thoroughly separates the fibres of the wood. The
time occupied in the foregoing operations is from eleven to eleven
and a half hours. It takes from nine to ten hours to free the pans
from alkali, when they are removed to washing-tanks with perforated
metal bottoms, where the material receives a final washing before
being bleached.

_Washing._--Each of the three digesters has a pan into which
its contents are discharged, and there are also four iron tanks
used for holding the liquors of various strengths obtained
from the cleansing of the pulp and a fifth tank is kept as the
separating-tank before mentioned. When the digester is blown,
the pulp is levelled down with a shovel, and the liquor from the
separating-tank is allowed to flow into it. The contents of the
next strongest pan are pumped upon it, while at the same time the
strongest store tank flows into this pan. This flowing from the
tank to the pan, pumping from here to the pan just blown, and from
there to the evaporators, is kept up until the liquor is not weaker
than 6° B. hot (130° F.). The second pan is now down to 4° B. hot,
and the process of "pumping back" is commenced. The two weakest
tanks are put upon this pan and pumped out of the bottom of it into
the two tanks in which are kept the strongest liquors. The two weak
tanks have been filled in the process of completing the cleansing
of the third pan (the weakest) on which water was pumped until the
last weak tank stood at only ½° B. This pan, now cleaned, is hosed
and pumped over to the washing tanks. A fresh blow is now made in
this pan, and the same treatment kept up as with the first pan.

The foregoing system is thus illustrated by Mr. Congdon:--

  Pan A.--Just blown.
   "  B.--Partly cleaned.
   "  C.--Almost cleaned.

  Tank 1.--3½°   B. hot.
   "   2.--2°    "   "
   "   3.--1°    "   "
   "   4.--½°    "   "

  Separating tank, strong.

A is levelled down; contents of separating-tank allowed to flow
upon it; B is pumped on to A; at the same time liquor from the two
strong store tanks is put on it (B), and this continued to be sent
from A to the evaporator until it is now weaker than 4° B. hot; the
process of "pumping back" is then commenced. The two weakest are
allowed in succession to flow on to it, and the liquor purified
from the bottom of B into the two strong tanks, filling No. 1,
the stronger, before No. 2. The weakest are filled in the process
of completing the cleansing of C, on which water is pumped until
the last tank from it tests only ½° B. C is now hosed and pumped
over to the washing tanks. A fresh digester is blown in C, and the
process repeated as with A.

The above system has been modified by having an extra pan into
which the liquor from the last pan blown (after sending to the
evaporators until down to 6° hot, and bringing down to 4° hot, by
the stored liquor) is pumped. When the strength is reduced to 4°
the pumping is stopped. The liquor from this pan is put in the next
pan blown, after the liquor from the separating-tank has been put
upon it, whereby an economy in time is effected.

The pulp, after being partially cleaned in the pans, still
contains an appreciable quantity of soda. It is hosed over to the
washing-tanks and receives a final washing with hot water. When the
pulp is thoroughly free from alkali, and the water flowing from
under the tank is colourless, the contents are hosed down by hot
water into the bleaching-tanks. The superfluous water is removed
by revolving washers, and about 1,000 gallons of a solution of
chloride of lime at 4° B. are then introduced, and the contents
agitated as usual. The bleaching occupies about six or seven hours,
when the pulp is pumped into draining tanks, where it is left to
drain down hard, the spent bleach flowing away. The stock is then
hosed and pumped into a washing-tank, where it acquires the proper
consistency for the machine. From here it is pumped into the stuff
chest, whence it goes over a set of screens and on to the machine,
from which the finished fibre is run off on spindles. The rolls
are made of a convenient size to handle, averaging about 100 lbs.
each. The fibre is dried on the machine by passing over a series
of iron cylinders heated by steam. The finished product is a heavy
white sheet, somewhat resembling blotting paper. The whole of the
foregoing operations are stated to occupy forty-five hours.


=Aussedat's Process.=--By this method the wood is disintegrated
by the action of jets of vapour. In one end of a cylindrical
high-pressure boiler, about 4½ feet in diameter and 10 feet high,
is fixed a false bottom, whereby the wood placed upon it may be
removed from the liquor resulting from steam condensed in the
chamber, the whole being mounted on lateral bearings which serve
for the introduction of the vapour, and the wood is fed through a
manhole at the upper end of the boiler. Taps are fixed at the upper
and lower ends for the liquid and uncondensed vapour. The wood
having been placed in the boiler, the jet is gradually turned on in
such a way that at the end of three or four hours the temperature
becomes about 150° C., the pressure being about five atmospheres,
which point is maintained for an hour. As the slightest contact
between the wood and the condensed water would at once discolour
the former, it is essential that the liquid be removed from time to
time by one of the outlets provided for the purpose.

The treatment above described is said to be suitable for all kinds
of wood, and although it is the usual practice to introduce it in
logs about a yard long, any waste wood, as chips, shavings, etc.,
may be used. It is preferable, though not necessary, to remove the
bark, but all rotten wood may be left, as it becomes removed in the
condensed water. The logs, after the above treatment, by which the
fibre is disintegrated and the sap and all matters of a gummy or
resinous nature are removed, are afterwards cut up by any suitable
means into discs of about an inch, according to the nature of the
fibre required. These are then introduced into a breaker, in which
they become converted into half-stuff, which, after being mixed
with a suitable quantity of water is passed through mills provided
with conical stones, in which it becomes reduced to whole-stuff.
The pulp thus prepared is principally used in the manufacture of
the best kinds of cardboard, but more particularly such as is used
by artists, since its light brownish shade is said to improve the
tone of the colours. Bourdillat says that in the above process
the vapour has a chemical as well as a mechanical action, for in
addition to the vapour traversing the cellular tissues of the wood
and dissolving a considerable portion of the cell-constituents,
acetic acid is liberated by the heat, which assists the vapour in
its action on the internal substance of the wood.


=Acid Treatment of Wood.=--A series of processes have been
introduced from time to time, the object of which is to effect
the disintegration of wood fibre by the action of acids. The
first of these "acid processes" was devised by Tilghmann in
1866, in which he employed a solution of sulphurous acid; the
process does not appear to have been successful, however, and
was subsequently abandoned, the same inventor having found that
certain acid sulphites could be used more advantageously. Other
processes have since been introduced, in which wood is treated in a
direct way by the action of strong oxidising acids, as nitric and
nitro-hydrochloric acids, by which the intercellular matters of the
wood become dissolved and the cellulose left in a fibrous condition.


=Pictet and Brélaz's Process.=--By this process wood is subjected
to the action of a vacuum, and also to that of a supersaturated
solution of sulphurous acid at a temperature not exceeding 212° F.
In carrying out the process a solution of sulphurous acid is used,
consisting of, say from ⅕ to ⅓ lb. avoirdupois of sulphurous acid
to each quart of water, and employed under a pressure of from three
to six atmospheres at 212° F. Under these conditions the cementing
substances of the wood "retain their chemical character without a
trace of decomposition of a nature to show carbonisation, while
the liquor completely permeates the wood and dissolves out all the
cementing constituents that envelop the fibres." In carrying out
the process practically, the wood is first cut into small pieces
as usual and charged into a digester of such strength as will
resist the necessary pressure, the interior of which must be lined
with lead. Water is then admitted into the vessel and afterwards
sulphurous acid, from a suitable receiver in which it is stored
in a liquid form until the proportion of acid has reached that
before named, that is, from 100 to 150 quarts of the acid to 1,000
quarts of water. The volume of the bath will be determined by the
absorbing capacity of the wood, and is preferably so regulated
as not to materially exceed that capacity. In practice it is
preferable to form a partial vacuum in the digester, by which
the pores of the wood are opened, when it will be in a condition
to more readily absorb the solution and thereby accelerate the
process of disintegration. When disintegration is effected, which
generally occurs in from twelve to twenty-four hours, according
to the nature of the wood under treatment, the liquor, which is
usually not quite spent in one operation, is transferred to another
digester, a sufficient quantity of water and acid being added to
complete the charge. In order to remove the liquor absorbed by the
wood, the latter is compressed, the digester being connected with
a gas-receiver, into which the free gas escapes and in which it
is collected for use again in subsequent operations. The bath is
heated and kept at a temperature of from 177° to 194° F. by means
of a coil in the digester supplied with steam from a suitable
generator. The wood, after disintegration, undergoes the usual
treatment to convert it into paper pulp, and may thus be readily
bleached by means of chloride of lime. The unaltered by-products
contained in the bath may be recovered and treated for use in the
arts by well-known methods.


=Barre and Blondel's Process= consists in digesting the wood for
twenty-four hours in 50 per cent. nitric acid, used cold, by which
it is converted into a soft fibrous mass. This is next boiled for
some hours in water and afterwards in a solution of carbonate of
soda; it is then bleached in the usual way.


=Poncharac's Process.=--In this process cold nitro-hydrochloric
acid (aqua regia) is employed for disintegrating wood in the
proportions of 94 parts of the latter to 6 parts of nitric acid,
the mixture being made in earthen vessels capable of holding 175
gallons. The wood is allowed to soak in the acid mixture for six to
twelve hours. 132 lbs. of aqua regia are required for 220 lbs. of
wood. When it is desired to operate with a hot liquid, 6 parts of
hydrochloric acid, 4 parts of nitric acid, and 240 parts of water
are used in granite tubs provided with a double bottom, and it is
heated by steam for twelve hours and then washed and crushed.


=Young and Pettigrew's Process.=--These inventors use either nitric
or nitrous acids, and the acid fumes which are liberated are
condensed and reconverted into nitric acid.


=Fridet and Matussière's Process.=--This process, which was
patented in France in 1865, consists in treating wood with
nitro-hydrochloric acid, for which purpose a mixture of 5 to 40 per
cent. of nitric acid and 60 to 95 per cent. of hydrochloric acid
is used, which destroys all the ligneous or intercellular matter
without attacking the cellulose. After the wood (or straw) has been
steeped in the acid mixture, the superfluity is drawn off, and
the remaining solid portion is ground under vertically revolving
millstones. The brownish-coloured pulp thus obtained is afterwards
washed and bleached in the usual way.

It is quite true that cellulose can be obtained from wood and
other vegetable substances by treatment with nitric acid alone,
or with a mixture of nitric and hydrochloric acids, but it will
be readily seen that the employment of such large quantities of
these acids as would be required to effect the object in view on a
practical scale, would be fraught with incalculable difficulties,
amongst which may be mentioned the insuperable difficulty of
obtaining vessels that would resist the powerful corrosive action
of the acids. Moreover, since nitric acid forms with cellulose an
explosive substance (_xyloidin_) of the gun cotton series, the risk
involved in the drying of the cellulose obtained would be quite
sufficient to forbid the use of processes of this nature.



CHAPTER VII.

_TREATMENT OF WOOD (continued)._

  Sulphite Processes.--Francke's Process.--Ekman's Process.--Dr.
  Mitscherlich's Process.--Ritter and Kellner's Boiler.--Partington's
  Process.--Blitz's Process.--McDougall's Boiler for Acid
  Processes.--Graham's Process.--Objections to the Acid or Sulphite
  Processes.--Sulphite Fibre and Resin.--Adamson's Process.--Sulphide
  Processes.--Mechanical Processes.--Voelter's Process.--Thune's
  Process.


=Sulphite Processes.=--An important and successful method of
treating wood has been found in employing sulphurous acid,
combined in certain proportions with soda, lime, or magnesia,
whereby a bisulphite of the alkaline or earthy base is obtained.
One of the principal attributes of these agents is that in
boiling wood at high pressures oxidation and consequent browning
of the fibres is prevented. Of these sulphite, or more properly
bisulphite, processes, several of those referred to below have
been very extensively adopted, and vast quantities of so-called
"sulphite pulp" are imported into this country from Norway,
Germany, Scandinavia, &c., the product from the latter source
being considered specially suited for the English market. Some of
these processes are also being worked in this country, but more
particularly those of Partington, McDougall, and Ekman.


=Francke's Process.=--In this process, which is known as
the "bisulphite process," the active agent employed for the
disintegration of wood is an acid sulphite of an alkaline or earthy
base, as soda or potassa, lime, &c., but it is scarcely necessary
to say that the process has since been modified by others. The
invention is applicable to the treatment of wood, esparto, straw,
etc., and may be thus briefly described:--A solvent is first
prepared, which is an acid sulphite of an alkali or earth, that
is, a solution of such sulphite with an excess of sulphurous acid.
As the cheapest and most accessible base the inventor prefers
lime. It has long been known that a solution of sulphite of lime,
combined with free sulphurous acid, would, at a high temperature,
dissolve the intercellular portions of vegetable fibres, leaving
the fibres in a suitable condition for paper manufacture; but Mr.
Francke claims to have determined the conditions under which this
can be effected with rapidity, and in such a way as to preserve the
strength of the fibres, and to have obtained a practical method
of preparing pulp by his process. For his purpose he employs a
moderately strong solution of the solvent at a high temperature,
with gentle but constant agitation. The acid sulphite is produced
by this process at small cost and at a temperature nearly high
enough for use in the following way:--A tower or column is charged
with fragments of limestone, which are kept wetted with a shower
of water; fumes of sulphurous acid, produced by burning sulphur,
or by roasting pyrites, etc., are then passed through the tower.
The liquid which collects at the bottom of the tower is the
desired solvent, which should have a strength of 4° to 5° B. It
is not essential that the limestone should be pure, as magnesian
limestone, etc., will answer equally well. The soluble alkalies,
as soda and potassa, may also be used when their greater cost is
not an objection. But for these alkalies the treatment is modified,
as follows:--The tower is charged with inert porous material, such
as coke, bricks, etc., and these are kept wetted by a shower of
caustic alkali at 1° to 2° B., while the sulphurous acid fumes
are passed through the tower. In like manner carbonate of soda or
potassa may be used, but in this case the solution showered on the
porous material should be stronger than that of the caustic alkali,
so that it may contain approximately the same amount of real
alkali. Whichever alkaline base be employed, the liquid collected
at the bottom of the tower should have a strength of 4° to 5° B.;
this being the acid sulphite of the base is used as the solvent
employed for the manufacture of pulp. When wood is to be treated,
it is freed as much as possible from resinous knots by boring and
cutting them out, and is then cut--by preference obliquely--into
chips of a ¼ to ¾ of an inch thick. Esparto, straw, and analogous
fibres are cut into fragments. The fibrous material and solvent
are charged into a digester heated by steam at a pressure of four
or five atmospheres, and consequently capable of raising the
temperature of the contents to about 300° F. As agitation greatly
promotes the pulping of the materials, Mr. Francke employs a
revolving cylindrical boiler, which is allowed to revolve while the
charge is under treatment.


=Ekman's Process.=--In this process, which in some respects bears
a resemblance to the preceding, native carbonate of magnesia
(magnesite) is first calcined to convert it into magnesia; it is
then placed in towers lined with lead, and sulphurous acid gas,
obtained by the burning of sulphur in suitable furnaces, is passed
through the mass, a stream of water being allowed to trickle down
from the top of the towers. The supply of gas is so regulated that
a continual formation of a solution of bisulphite of magnesium, of
an uniform strength, is obtained; great care, however, is necessary
to avoid excess and consequent loss of sulphurous acid by its
conversion into sulphuric acid. In boiling, the fragments of wood,
previously crushed by heavy rollers, are placed in a jacketed,
lead-lined, cylindrical boiler, suspended on trunnions, so that it
can be inverted to remove the charge. The pressure in the outer
jacket is 70 lbs. per square inch, and that within the boiler is
90 lbs. per square inch. The boiling occupies twelve hours. This
process has been extensively worked by the Bergvik and Ala Company,
of Sweden, for many years with great success, and we understand
that the company has been turned over to an English company--the
Bergvik Company, Limited. The Ilford Mill and Northfleet Works have
been largely supplied with sulphite pulp from the Swedish works.

One great drawback to the bisulphite processes is that the boiling
cannot be effected in iron boilers unless these be lined with some
material which will protect the iron from the destructive action of
the bisulphite, which, being an acid salt, would exert more action
upon the iron than upon the fibre itself, and the solution of iron
thus formed would inevitably prove injurious to the colour of the
fibre. In several of the systems adopted iron boilers lined with
lead have been used, but the heavy cost of this material and its
liability to expand unequally with the iron, especially at the high
temperatures which the solvent necessarily attains under pressure,
causes the lead to separate from the iron, while it is apt to bulge
out in places, and thus becomes liable to crack and allow the acid
liquor to find its way to the interior of the iron boiler which it
was destined to protect. To overcome this objection to the simple
lead lining, Dr. Mitscherlich patented a process which has been
extensively adopted in Germany, and is now being carried out by
several companies in different parts of America. This process is
briefly described below.


=Dr. Mitscherlich's Process.=--The digester employed in this
process is lined with thin sheet lead, which is cemented to the
inner surface of the boiler by a cement composed of common tar and
pitch, and the lead lining is then faced with glazed porcelain
bricks. In this process a weaker bisulphite of lime is used than
in Francke's, and the time of boiling is consequently considerably
prolonged.


=Ritter and Kellner= have proposed to unite the inner surface of
the boiler to its lead lining by interposing a soft metal alloy,
fusible at a temperature lower than that of either metal, and it
is claimed that the iron and lead are thus securely united, while
the alloy being fusible under the normal working temperature of the
digester, the lead lining can slide freely on a boiler shell.


=Partington's Process.=--This process, which has been for some
time at work at Barrow, and for the further development of which
a private company, entitled the Hull Chemical Wood Pulp Company,
Limited, has been formed, consists in the employment of sulphite
of lime as the disintegrating agent. The process consists in
passing gaseous sulphurous acid--formed by burning sulphur in a
retort, into which is forced a current of air at a pressure of
5 lbs. to the square inch--through a series of three vessels,
connected by pipes, the vessels being charged with milk of lime.
The first two of these vessels are closed air-tight, and the gas
is then introduced, while the third vessel remains open; from this
latter a continuous stream of nitrogen escapes, due to the removal
of the oxygen by the burning sulphur from the air passed into the
retort. This process is said to be a very economical one, so far as
relates to the cost of materials used.


=Blitz's Process.=--This process consists of employing a mixture
composed of bisulphite of soda 2 parts, caustic soda 1 part; and
vanadate of ammonia 1 gramme, in hydrochloric acid 4 grammes to
every 6 kilogrammes of the bisulphite. The wood, after being cut
up in the ordinary way, is submitted to the action of the above
mixture, under a pressure of three or four atmospheres, for from
four to eight hours, and the pulp is then ground; it is said to
possess some of the qualities of rag pulp and to look much like it.


=McDougall's Boiler for Acid Processes.=--This invention is
intended to obviate the difficulties which arise in using
lead-lined boilers, owing to the unequal expansion and contraction
of the lead and the iron on their being alternately heated by steam
and cooled, on the discharge of each successive batch of pulp. This
invention consists in constructing the boilers with an intermediate
packing of felt, or other compressible and elastic material,
so that when the interior leaden vessel is heated, and thereby
enlarged and pressed outwards by the steam, the compressible and
elastic packing yields to the pressure and expansion. Also in the
cooling of the vessels the packing responds to the contraction,
and approximates to its original bulk and pressure between the two
vessels, and so prevents the rupture or tearing of the lead and
consequent leakage and other inconveniences. Another part of this
invention consists in the construction of the outer iron or steel
vessel in flanged sections, which are fitted to incase the interior
leaden vessel with a space between the two vessels, into which the
compressible and elastic materials are packed. In the construction
of these vessels the iron or steel flanged sections are placed on
to the leaden vessel and packed with the compressible and elastic
lining in succession. As each section is packed it is screwed
close up to the adjoining section by the screw bolts, fitted into
corresponding holes in the flanges of the contiguous section until
completed. This method of construction secures economy by the
retention of the heat, which is effected by the packing between the
two vessels. The materials used for the packing are caoutchouc,
felt, flocks, asbestos, etc., and a space of about two inches
between the vessels is preferred, into which the packing is filled.


=Graham's Process.=--This process consists in boiling fibrous
substances in a solution of sulphurous acid, or a sulphite or
bisulphite of soda, potash, magnesia, or lime, or other suitable
base and water. The boiling is preferable conducted in a closed
boiler, lined with lead, to protect it from the action of the
chemical substances used, and is fitted with a valve which can be
opened to allow the gases and volatile hydrocarbons contained in
and around the fibres to escape. The method of carrying out the
process has been thus described:--"In carrying out the process
there is a constant loss of sulphurous acid gas going on, and
consequently a continual weakening of the solution employed, to
avoid which it is preferable to employ monosulphite of potash,
soda, magnesia, lime, or other suitable base, and water. Either
of these substances, or a suitable combination of them, and
water are placed in the boiler with the fibrous substances to be
treated, and the temperature raised to the boiling point. After
the hydrocarbons, air, and gases natural to the fibrous substances
have been driven out by the heat and allowed to escape, sulphurous
acid, in its gaseous or liquid state, or in combination with
either of the bases referred to, is pumped or injected into the
boiler. There is thus forming in the closed boiler a solution
containing an excess of sulphurous acid above that required to
form, in combination with the base, a monosulphite. The operation
of injecting sulphurous acids, or the sulphites, may be repeated
from time to time during the boiling, so as to fully maintain,
and if necessary increase, the strength and efficiency of the
chemical solution. It is said that by this process a saving of the
chemicals employed is effected, as little or no sulphurous acid gas
is lost during the time the gaseous hydrocarbons, air, and other
gaseous matters are being expelled from the fibrous materials.
If an open vessel is used instead of a closed boiler, it will be
necessary to keep the solution at a fairly uniform strength, and
if necessary to increase the strength, but the result will be
substantially the same; but as it is evident that, when using an
open boiler, the excess of sulphurous acid supplied during the
boiling will be constantly driven off as gas, it must be replaced
by further injections, while the acid fumes may be conveyed away
and condensed, so as to be available for further use. When the
fibrous substances are boiled as above, with the addition of
potash, soda, etc., during the boiling, the result will be equally
beneficial. The inventor prefers to inject the sulphurous acid
or its combinations into the boiler at the bottom, and to cause
it to come in contact with the solution therein before reaching
the fibrous materials. For this purpose there is formed a kind of
chamber beneath the boiler, but separated from it by a perforated
disc or diaphragm of lead or other suitable material not acted upon
by the solution, so as to allow the latter to fill the chamber, to
which is connected a pipe, through which the sulphurous acid or
solutions of the sulphites is forced by any suitable apparatus.


=Objections to the Acid or Bisulphite Processes.=--While
the various methods of boiling wood in caustic soda at high
temperatures are well known to be open to serious objections, the
acid treatment of wood also presents many disadvantages, which
it is to be hoped may be yet overcome. In reference to this,
Davis makes the following observations:--"In the acid treatment
of wood for the purpose of converting the fibres into pulp for
use in paper manufacture, the general practice has been to use
alkaline solutions of soda, combined in various proportions with
certain acids, such, for instance, as sulphurous acid, hydrochloric
acid, etc. These solutions have been heated in digesting vessels,
and the high temperature resulting from this process of heating
developing a pressure of from six to seven atmospheres, the wood
being disintegrated by the action of the boiling solutions, the
gum, resinous constituents, and other incrustating or cementing
substances that bind the fibres together are decomposed, destroyed,
or dissolved, while pure cellulose, which constitutes the essential
element of the ligneous fibres, is separated therefrom. To this end
high temperatures had to be employed, otherwise the disintegration
was found to be only partial, the wood remaining in a condition
unfit for further treatment. The high temperature not unfrequently
converts a large proportion of the resinous and gummy constituents
of the wood into tar and pitch--that is to say, carbonaceous bodies
that penetrate into the fibre and render its bleaching difficult,
laborious, and costly, while the frequent washing and lixiviation
necessary to bleach such products seriously affect the strength
of the fibre and its whiteness, and also materially reduce the
percentage of the product, in some instances to the extent of 18
per cent. These difficulties and detrimental results materially
enhance the cost of production, while the fibre itself suffers
considerably in strength from the repeated action of the chloride
of lime.... The difficulties are chiefly due to the carbonisation
of certain constituent parts of the fibres under temperatures
exceeding 212° F., such carbonised matters being insoluble and
incapable of being bleached, and as they permeate the fibre, cannot
be entirely removed.

"To overcome these difficulties, the wood should be chemically
treated at a temperature sufficiently low to ensure that the
decomposition of the connecting substances of the fibres will
remain chemically combined with the other elements, such as
hydrogen, oxygen, and nitrogen, in order to obtain an increased
product of superior quality and render the process more economical."


=Sulphite Fibre and Resin.=--A German manufacturer sent the
following communication to the _Papier Zeitung_, which may
be interesting to the users of sulphite pulp:--"In making
[disintegrating] cellulose by the soda or sulphite process, the
object in boiling is to loosen the incrusting particles in the
wood, resin included, and to liberate the fibres. The resin is
dissolved both in the soda and sulphite processes, but in the
former it is at the same time saponified, and is consequently
very easily washed out. In the case of sulphite fibre, however,
the resin attaches itself by its own adhesiveness to the fibres,
but can also be removed by as hot washing as possible, and adding
a little hydrochloric acid, which produces a very great effect.
At the same time, however, sulphite fibre loses in whiteness
by thorough washing, and assumes a reddish-grey shade. As the
paper manufacturer insists upon white fibre, the manufacturer of
sulphite fibre not only often omits washing, but adds some sulphite
solution (bisulphite of lime). This not only enables him to give
his customers white fibre, but he also sells a quantity of the
incrusting particles and sulphite residuum as cellulose.

"So long as the manufacturer looks more to white than to
well-washed cellulose, or does not wash it well before working up
the fibre, these annoyances cannot be avoided. Not only this, but
other disadvantages will be added in the course of time, as the
action of the sulphurous acid in the pulp will have very injurious
consequences on metals--[and on the fibre itself?] especially
iron--coming in contact with it. This should be the more avoided,
as the whiteness of the unwashed cellulose is of very short
duration. The paper made from it soon turns yellow and becomes
brittle. Well-washed sulphite fibre, on the other hand--provided
no mistakes have been made in the boiling process--makes a strong,
grippy paper, which can withstand both air and sunlight. I have
made no special studies as to resin, but believe that pine and fir
act differently, especially with solvents."


=Adamson's Process.=--Mr. W. Adamson, of Philadelphia, obtained
a patent in 1871 for the use of hydrocarbons in the treatment of
wood. His process consisted in treating the wood with benzine in
closed vessels, under a pressure of 5 to 10 lbs., according to the
nature of the wood. His digester consisted of an upright cylinder,
in which the wood-shavings were placed between two perforated
diaphragms. The mass was heated beneath the lower diaphragm by
a coil through which steam was passed. The vapours which were
given off were allowed to escape through a pipe on the top of the
digester, to which was connected a coil immersed in a vessel of
cold water, and the condensed liquid then returned to the lower
part of the digester. The remaining portion of the benzine in the
digester, which was still liquid but saturated with the extracted
matters, was drawn off through a faucet at the bottom. Benzine
being a very cheap article in America, a similar process was
recommended in another patent by the same author for extraction of
pitch and tar from rags [tarpaulin, ropes, &c.?], and for removing
oil from rags and cotton waste.


=Sulphide Processes.=--Many attempts were made about thirty years
ago, and in subsequent years, to employ the soluble sulphides as a
substitute for caustic soda in boiling wood and other fibres, but
these processes do not appear to have been very successful. Later
improvements in the construction of boilers or digesters, however,
seem to have induced further experiments in this direction, and we
understand that several sulphide processes are being worked on the
Continent, the processes of MM. Dahl and Blitz being amongst them.
One of the supposed advantages of these sulphides over caustic soda
is that by evaporation and calcination of the liquors, or leys, by
which the organic matters become destroyed, the original product
would be recovered, which merely requires to be dissolved out for
further use. There are, however, several important objections to
the use of sulphides in this way, amongst which may be mentioned
the deleterious vapours which they emit; and this alone would
doubtless prevent their employment--at all events in this country.


=II. Mechanical Processes.=--Besides the various chemical methods
of separating cellulose from woody fibres, before described,
certain processes have been devised for reducing wood to the
condition of pulp directly by mechanical means without the aid
of any chemical substance whatsoever. In this direction Heinrich
Voelter, of Wurtemburg, appears to have been the first to introduce
a really practical process for the conversion of wood into pulp
for paper-making, although, as far back as 1756, Dr. Schaeffer,
of Bavaria, proposed to make paper from sawdust and shavings
mechanically formed into pulp: the process was not successful,
however, with the machinery then at his command.


=Voelter's Process for Preparing Mechanical Wood Pulp.=--In 1860-65
and 1873 Voelter obtained patents in this country for his methods
of treating wood mechanically, and the process may be thus briefly
described:--Blocks of wood, after the knots have been cut out by
suitable tools, are pressed against a revolving grindstone, which
reduces the material to a more or less fine condition, but not in
a powdery form, and the disintegrated fibre is caused to press
against a wire screen, which allows the finer particles to pass
through, retaining the coarser particles for further treatment.

[Illustration: Fig. 17A.--Voelter's Wood-pulping Machine.

  [_To face page 78._]

The apparatus employed, which is shown in Fig. 17A, consists of a
pulping apparatus A, with vat K, in which the revolving stone S is
placed; the blocks of wood are held against the stone at _p p_,
and water is introduced at G, and the revolving stone carries the
pulp against the screen E, which admits the passage of the finer
particles of the wood, while the coarser particles are led by the
trough F to the first refining cylinder B, after passing through an
oscillating basket, which retains the coarser particles. From
thence it is led through a distributing apparatus and hopper C, to
be uniformly supplied to the refining cylinder D, these cylinders
being of the ordinary construction, and, as usual, covered with
fine gauze wire sieves. The ground material which fails to pass
through the sieves is transferred by an elevator to the millstones
E, which are of ordinary construction, and after leaving these
unites with the finer fibres which pass through E, the whole now
entering a mixing reservoir F, whence it is thrown on to the
cylinder G, and the pulp which passes into this is distributed
on to a similar cylinder H, the contents of which then passes
through the last cylinder I, which is differently constructed
to the others, inasmuch as its lower part is surrounded by an
impervious leather jacket, so that the pulp ascends in order to
enter it. The disintegrated fibres that are retained by the wires
of the cylinders pass into the refiners, which consist of a pair
of horizontal cylinders of sandstone, one of which (the upper one)
only revolves, and by the action of these the coarser fibres become
further reduced, the finer particles, as before, passing through
the wire gauze of the cylinders, the operation being repeated in
the same order until the whole of the fibres have passed through
the sieves.


=Thune's Process.=--Mr. A. L. Thune, of Christiana, U.S.A., has
recently patented an apparatus for disintegrating wood, which
consists of a grinding apparatus connected to a turbine. In this
arrangement the grindstone, fixed on a shaft, is worked by a
turbine, and the wood, which is used in small blocks, is pressed
against the stone by means of a series of hydraulic presses. The
fine pulp is afterwards made into thick sheets by means of a
board-machine, the pulp, mixed with water, passing down a shoot
into a vat beneath, in which is a revolving cylinder covered with
wire-cloth, which in its revolution carries with it a certain
quantity of pulp in a continuous sheet; this is taken on to an
endless travelling belt by means of a small couch-roll, and passes
on to a pair of rolls, round the upper one of which the sheet
becomes wound, and is removed when sufficiently thick.



CHAPTER VIII.

_TREATMENT OF VARIOUS FIBRES._

  Treatment of Straw.--Bentley and Jackson's Boiler.--Boiling
  the Straw.--Bertrams' Edge-runner.--M. A. C. Mellier's
  Process.--Manilla, Jute, etc.--Waste Paper.--Boiling Waste
  Paper.--Ryan's Process for Treating Waste Paper.


=Treatment of Straw.=--As a paper-making material, the employment
of straw is of very early date, a patent for producing paper from
straw having been taken out by Matthias Koops as far back as
1801. The material, however, was used in its unbleached state,
and formed a very ugly paper. White paper was not obtained from
straw until 1841, but no really practical method of treating this
material was devised until about ten years later, in France, when
MM. Coupier and Mellier introduced a process which, with subsequent
modifications, has been extensively adopted. A great advance in
the manufacture of paper from straw has since been effected by the
introduction of various boilers, specially constructed for boiling
the material at high pressures, and for keeping the alkaline
liquors freely circulated amongst the fibre during the progress of
the boiling. These boilers are of different forms--being either
cylindrical or spherical--and are preferably of the revolving type,
which causes the caustic ley employed in the boiling to become
uniformly mixed with the fibre. Sometimes the vomiting boilers
described elsewhere are used by paper-makers in preference to those
referred to.


=Bentley and Jackson's Boiler.=--This boiler, a representation of
which is shown in Fig. 18, is 7 feet in diameter, 18 feet long on
the cylindrical surface, with hemispherical ends of Martin-Siemens
steel plate 7/16 inch thick in the shell, and ½ inch thick in
the ends. It is double riveted in the longitudinal seams, has
two manholes 3 × 2, forged out of solid steel plate. Inside are
two perforated lifting plates or shelves, each 1 foot wide, ¼
inch thick, the full length of the shell, and secured to the ends
by strong angle-irons; it is supported on two turned cast-iron
trunnions. These boilers are tested by hydraulic pressure to 120
lbs. per square inch.

[Illustration: Fig. 18.]

The varieties of straw generally used for paper-making in this
country are wheat and oats, though rye and barley straws are also
used, but in a lesser degree. The treatment of straw differs
greatly at different mills, some makers using strong liquors
and boiling at a lower pressure, while others prefer to use
less caustic soda and boil at a higher pressure. There can be
little doubt, however, that the high temperatures resulting from
boiling at very high steam pressure must deteriorate the fibre
considerably, causing subsequent loss of fibre in the processes of
washing and bleaching.

=Boiling the Straw.=--The straw is first cut into short lengths
of one or two inches by means of a chaff-cutter, or by a machine
similar to a rag-cutter, and the cut material is then driven by
an air-blast through a wooden tube into a chamber having coarse
wire-gauze sides: a second chamber surrounds this, in which the
dust from the straw collects as it passes through the wire gauze.
The winnowed straw, freed from dust and dirt, is then conveyed in
sacks to the boilers. In charging the boilers, a certain quantity
of ley is first introduced, and steam also, and the cut straw then
added, which soon becomes softened, and sinks to the bottom of the
boiler, when further quantities of the material are added, until
the full charge has been given. The requisite proportion of ley
and water is then run in and the head of the boiler secured in its
place. Steam is now turned on, until a pressure of 20 to 40 lbs.,
or even more, has been reached, when the boiling is kept up for
3½ to 8 hours, according to the pressure used and the strength of
the alkaline liquor, which varies from 9° to 16° Tw. From 10 to 20
lbs. of caustic soda per cwt. of straw are generally required to
boil the material thoroughly. The boiling being complete, steam is
turned off, and when the boiler has somewhat cooled, the material,
which is in the form of a pulp, is discharged by the pipes beneath
into a large tank or strainer, the bottom of which is fitted with
a series of plates having long narrow openings or slits, through
which the liquor drains. The pulp is then washed with water, and
again allowed to drain thoroughly, after which it is dug out and
transferred to the potcher to be again washed and bleached. At
some mills the straw is boiled whole and not subjected to any
preliminary cutting In such cases the boiled straw, not being so
fully pulped as when cut into short lengths, is emptied from the
boiler through the manholes used for charging the material into the
boiler.


[Illustration: Fig. 19.]

=Bertrams' Edge-runner.=--For the purpose of crushing the knots
of the straw, and other hard particles derived from weeds, etc.,
a machine termed the "koller-gang" or "edge-runner" is sometimes
employed. This machine, which is manufactured by Bertrams, Limited,
and of which an illustration is given in Fig. 19, consists of two
large millstones, made from hard red granite, the surfaces of
which are sometimes grooved with V-shaped equidistant grooves.
These stones are worked by a horizontal spindle, and are caused to
revolve very rapidly in an iron basin, in which the washed pulp
is placed, and by this means the knots and harder portions of the
fibre not fully acted upon by the caustic alkali, become so reduced
as to be more readily accessible to the action of the bleach,
and thus a very superior straw pulp is produced. In using this
machine in the way indicated, the washed pulp is mixed in a chest
provided with agitators, with water, is then pumped into a second
chest above it, from whence it flows into the basin shown in the
engraving, while the stones are revolving.


=M. A. C. Mellier's Process.=--By this method the straw is first
cut into small lengths as usual; it is then steeped for a few hours
in hot water, and afterwards placed by preference in a jacketed
boiler, the object being to heat the materials without weakening
the ley by the direct introduction of steam into the body of the
material. The boiler is to be heated to a pressure of 70 lbs. to
the square inch, or to a temperature of about 310° F., by which
means, it is said, a considerable saving of alkali is effected,
as also time and fuel, as compared with the ordinary practice of
boiling. The alkaline ley which M. Mellier prefers to use is from
2° to 3° B., or of the specific gravity of from 1·013 to 1·020,
and in the proportion of about 70 gallons of such solution to each
cwt. of straw. The boiler should revolve very slowly, making about
1 or 2 revolutions per minute. The boiling occupies about 3 hours,
at the pressure named, when the steam is turned off and cold water
passed through the jacket of the boiler, which assists in cooling
the pulp, the water thus used being afterwards employed in washing
the pulp. The pulp is then thoroughly washed until the last water
runs off quite clear, when it is next steeped for about an hour
in hot water acidulated with sulphuric acid, in the proportion of
about 2 per cent. of the weight of the fibre. The pulp is then
washed with cold water, when it is ready for bleaching in the usual
way.


=Manilla, Jute, etc.=--Previous to boiling these fibres it is
usual to cut them into short pieces by a machine such as is used
for cutting straw, after which they are cleaned in a willowing and
dusting machine. The boiling is then conducted in the same way as
for esparto. Manilla fibre is not so much used in this country
as in the United States, where its employment forms an important
feature in the manufacture of certain kinds of paper. Some idea of
the extent to which it is used by the paper-makers of America may
be gleaned from the following statement of Mr. Wyatt:--"Another
large and important branch of the American paper trade are the
mills running on news and Manilla paper. Many of these mills turn
out a vast quantity of paper, running up to two hundred tons per
week, besides making their own ground wood pulp. The American news
is composed mainly of ground wood pulp, with an admixture of about
15 to 25 per cent. of sulphite wood or jute fibre, and not much
loading, and the machines are run at high speed. What is termed
Manilla paper is very largely used in the States, and much more so
than with us for common writings, envelopes, and wrapping papers.
The paper is composed of Manilla, jute fibre, old papers, etc., and
is highly finished at the machine. I was told of one mill belonging
to a large company running altogether six mills on news and
Manilla, turning out, with one 96-inch machine and beater capacity
of 1,800 lbs., and one Jordan, 10 to 12 tons of 2,000 lbs., of
Manilla paper per day at an average speed of 200 feet per minute."

Jute is seldom reduced to the condition of a fine white pulp since
the treatment necessary to obtain that condition would result in
a weak fibre; it is usual, therefore, to only partially reduce
the material, when a strong fibre is obtained, which, lacking
in whiteness, is used for coarse papers. This also applies to
Adamsonia, or Baobab, another description of bast obtained from
the West Coast of Africa. These fibres are chiefly used for papers
which require strength rather than whiteness of colour, such as
wrapping papers, &c.

"Broke" paper is a term applied to paper which has been imperfectly
formed on the paper machine or damaged while passing over the
drying cylinders. Imperfect sheets when they are not sold as
_retree_, and clean waste paper, also come under this designation
and are re-converted into pulp after undergoing the treatment
described below.


=Waste Paper.=--In treating waste paper for conversion into pulp
for paper-making, it is doubtless advisable to separate, as far as
can be done economically, papers which have been written upon with
common ink, as old letters, documents, &c., from printed papers,
since the latter require a more severe treatment than the former.
While simple boiling in water containing a little soda-ash will
discharge ordinary writing ink, printer's ink can only be extracted
by using rather strong solutions of soda-ash or caustic soda; and
even with this treatment it can only be rendered serviceable for an
inferior paper, owing to the grey colour of the resulting pulp, due
to the carbon of the printer's ink, upon which the alkali has no
solvent effect.


=Boiling Waste Paper.=--This is sometimes effected in iron vats,
about 8 feet deep and 8 feet in diameter at the bottom, and about
6 inches wider at the top. At the bottom of each vat is a false
bottom, closely perforated with small holes. Steam is introduced
by a pipe below the false bottom, which passes through the
perforations and thus becomes uniformly distributed to all parts
of the vat. To facilitate the emptying of the vats, the false
bottoms have connected to them three or four iron rods, to the
tops of which iron chains are hooked, and by this means the false
bottom, carrying the mass of boiled paper can be raised by a steam
hoisting engine or crane and deposited where desired. When the
boiling is commenced, the vat should first be about one-fourth
filled with a solution of soda-ash, and the steam then turned on.
When the liquor boils, the papers having been previously dusted,
are introduced gradually, and well distributed through the liquor;
if they are thrown into the vat in large quantities at a time, and
especially if they are in a compact state, the portions in contact
may not be reached by the liquor, and an imperfect boiling will be
the result. To ensure a uniform distribution of the boiling liquor
over the surface of the material, an iron pipe extends from the
centre of the false bottom to nearly the top of the vat, and this
pipe is covered with a hood, which causes the soda liquor to be
evenly spread over the whole mass. The vats are either cased with
wood or coated with asbestos to prevent the escape of heat, and
the vessel is covered with a flat iron cover, which is generally
in two halves. The steam enters the tubs at the side, below the
false bottom, and the exhausted liquor is drawn off through a valve
connected to the bottom of the vat. In some mills the liquor is
not drawn off after each boiling, but the boiled paper is hoisted
from the vat as before described, and the liquor strengthened by
the addition of from 10 to 20 lbs. of soda-ash for each 100 lbs.
of the paper to be next boiled. Paper that is thickly coated with
printing ink requires an extra dose of soda-ash. The boiling is
continued for twelve to twenty-four hours according to the nature
and condition of the waste paper under treatment.

Waste papers are frequently boiled, after dusting, in revolving
boilers, in a solution of soda-ash or caustic soda, but it not
unfrequently happens that some portions of the material become so
agglomerated or half pulped during the boiling that the alkali
fails to reach all the ink, and as this cannot be removed by the
after processes of washing and breaking, it remains in the body
of the pulp and necessarily forms a constituent part of the paper
to be produced from it. The mass, when discharged from the boiler
and drained is then conveyed to the washing-engine, in which it
becomes broken and freed from alkali and so much of the ink as may
have been dissolved or loosened, and it is afterwards treated in
the beater and mixed with varying portions of other paper stock,
according to the quality of paper to be produced. In some mills the
boiled waste paper is disintegrated after boiling, by means of the
edge-runner (Fig. 19).


=Ryan's Process for Treating Waste Paper.=--The following process
for treating waste paper so as to produce a "first-class clean
paper" therefrom, was patented by Mr. J. T. Ryan, of Ohio. The
waste paper is first passed through a duster in the usual way, all
thick old books being previously torn apart to separate the leaves.
The papers are then boiled in a hot alkaline liquor without pulping
them, whereby the alkali acts on the surfaces of the papers, and
dissolves off, carrying away all the ink into the liquor. The
papers, which are still in sheet form, are then drained as free as
convenient from the alkaline liquor, and are next washed in the
washing-engine, which leaves the material perfectly clean. It is
then pulped in the beating-engine; and it is claimed that it can be
formed into first-class paper without the addition of any new or
expensive paper stock. The details of the process are thus given by
the patentee: "Into a bucking-keir put a soda-ash solution having
a density of 5° B., at 160° F., put in the stock, and shower for
eight hours at a temperature of 160° F., without pulping the paper,
then lift and drain, and cleanse well in the washing-engine; then
pulp and form into paper. As the draining will always be imperfect,
each charge removed will carry away some of the soda-ash solution,
and leave the remainder of impaired strength. After each drainage
add water to make up for loss in quantity of the solution, and add
enough soda-ash solution at a density of 13° B., to bring all the
liquor up to 5° B. at 160° F. In about eighteen working days the
liquor will have accumulated considerable ink and other matter.
Then blow one half of the liquor, and restore the quantity for
proper working. None of the soda-ash solution is wasted, except
such as falls to drain and what is blown out as last mentioned." In
carrying out this process every care must be taken to guard against
pulping before the alkali is washed out.



CHAPTER IX.

_BLEACHING._

  Bleaching Operation.--Sour Bleaching.--Bleaching with Chloride
  of Lime.--Donkin's Bleach Mixer.--Bleaching with Chlorine
  Gas (Glaser's Process).--Electrolytic Bleaching (C. Watt's
  Process).--Hermite's Process.--Andreoli's Process.--Thompson's
  Process.--Lunge's Process.--Zinc Bleach Liquor.--Alum Bleach
  Liquor.--New Method of Bleaching.


=Bleaching Operation.=--The half-stuff treated in the
breaking-engine is run into the potcher, and the water it contains
is lifted out as far as practicable by the washer; the spent liquor
from the presses or drainers is then run in in lieu of water, and
as much fresh bleaching liquor as may be required is then measured
in, and in from two to six hours the pulp becomes perfectly
white. "However well managed a mill may be," says Mr. Arnot, "it
is scarcely possible to avoid having a small residue of unused
chlorine in the liquid which drains from the bleaching stuff." The
rule, therefore, is to use this liquor in the way above indicated,
by which the unexhausted chlorine, operating upon fresh half-stuff,
becomes available, and is, therefore, not wasted. "That as little
of this residual chlorine as possible may remain in the stuff,"
Mr. Arnot further observes, "when put into the beating-engine,
powerful hydraulic presses are employed to compress the stuff
and squeeze out the liquid. These presses should be large enough
to contain easily the whole contents of a poaching-engine, and
of unexceptional workmanship. The perforated lining especially
should be carefully prepared and properly secured. I have seen
much trouble from negligent workmanship in this respect. Recently
I examined a number of samples of press drainings, and found
the unexhausted chlorine to vary very much--from a few grains of
bleaching powder per gallon to about one ounce."

Sometimes it is the practice to partly fill the potcher with water,
and the engine being set in motion, the half-stuff is gradually
introduced until the full charge has been given, and the stuff is
then washed for some time, after which the drum-washer is raised,
and the bleaching liquor then run in, care being taken that the
necessary quantity is not exceeded, otherwise the fibre will
suffer injury from the chemical action of the bleaching agent.
When vitriol is employed to liberate the hypochlorous acid, the
vitriol, previously diluted with water, should be placed in a
small lead-lined tank in such a position that the acid liquor may
slowly trickle into the engine at the rate of 1 lb. of sulphuric
acid in twenty minutes. As soon as the bleaching is complete the
stuff is emptied into large stone chests, each of which will hold
the contents of two engines. On the bottom of these chests are
perforated zinc drainers, while a similar drainer runs up the back
of each chest. The bleached stuff is allowed to remain as long as
may be convenient in these chests, after which it is removed to
the beating or refining engines. In some mills the bleaching is
effected in the breaking-engine, while at other mills the operation
is performed in the beating-engine.

In bleaching it is considered to be more advantageous to employ
moderately strong liquors rather than weaker ones, inasmuch as
the object is effected in less time than when weaker liquors are
employed. An extreme in the opposite direction, however, must be
avoided, since a very strong bleach will inevitably cause injury to
the fibre. Sometimes the potchers are fitted with steam-pipes, in
order that the diluted bleaching liquor may be heated, if required,
to facilitate the operation. If the temperature be raised too high,
however, the effect upon the fibre will be at least as injurious
as if too strong a bleach were employed. It must also be borne in
mind that in either case, after the pulp has been bleached and the
liquor allowed to run off, the mass has to remain some time--even
if pressed to remove as much of the liquor as possible--in direct
contact with the products resulting from the decomposition, and
probably some undecomposed hypochlorite also, which will continue
their chemical action upon the fibre until removed by washing, or
neutralised by one or other of the agents employed for the purpose.


=Sour Bleaching.=--When the bleaching liquor, after acting upon
the half-stuff for some time, has become partially exhausted,
dilute sulphuric acid--about one part acid to fifteen parts of
water--is added, which, by liberating hypochlorous acid, hastens
the bleaching considerably, and when the chemical action resulting
from this treatment is nearly complete, the spent liquor is
allowed to drain away, and fresh bleaching liquor is introduced,
the strength being regulated by the progress made in the first
case, which will depend upon the character of the fibre treated.
In the second application of the bleach no acid is used. When
sulphuric acid is added to the bleaching liquor, as above, the
process is termed _sour bleaching_. Sometimes hydrochloric acid is
used for this purpose, but in either case it is necessary to avoid
employing the acid in too concentrated a state, or in too great a
quantity, otherwise free chlorine will be liberated, which, besides
being injurious to the health of the workmen and the surrounding
machinery, also involves loss, while the colour and strength of the
fibre itself will also be impaired. In some mills the bleaching is
effected in the beating-engine, the bleaching liquor being pumped
in while the machine is in motion.

Respecting the time which the bleaching operation should occupy,
there appears to be some difference of opinion, or, at all events,
the practice seems to vary in different mills, but there is, no
doubt, an advantage, so far as ultimate yield is concerned, in
moderately slow bleaching at a moderate temperature, inasmuch as
there is less risk of chemical action upon the cellulose itself
than when strong liquors are used, at a higher temperature, with a
view to hasten the operation and economise the bleaching powder.


[Illustration: Fig. 20.]

=Bleaching with Chloride of Lime= (_Preparation of the Bleaching
Liquor_).--Chloride of lime, or hypochlorite of lime, commonly
called bleaching powder, when well prepared, contains from 32 to
35 per cent. of active chlorine. Being readily decomposed by the
air, and also by heat, this substance should always be stored in a
cool and dry place until required for use. A solution of bleaching
powder is generally prepared in large tanks lined with lead, which
are provided with agitators or stirrers, so that the powder, when
added to the water, may be freely diffused, and its active material
dissolved in the liquid. A machine, or "bleach-mixer," manufactured
by Messrs. Bryan Donkin and Co., of Bermondsey, is shown in Fig.
20, which is so constructed that the strong bleach liquor does
not destroy it. The device for agitating the contents of the tank
explains the principle of the machine. To prepare the bleaching
liquor, about ½ lb. of chloride of lime to each gallon of water
is used, which yields a liquor at about 6° T. When the required
quantity of bleaching powder and water have been introduced into
the mixer and sufficiently agitated, the vessel is allowed to
rest until the residue, which chiefly consists of free lime and
its carbonate, has subsided, when the clear liquor may be run off
for use. When all the clear liquor has been drawn off the residue
should be washed with water, and after again settling, the washing
water run off, and fresh water added, these washings being repeated
as often as necessary to remove the last traces of the "bleach," as
it is technically called. The washing waters may be used in lieu
of water in the preparation of fresh bleaching liquors. In some
mills the bleaching powder is mixed with from 2 to 3 times its
weight of water; the mixture is then well agitated and the residue
afterwards allowed to settle, the clear solution being afterwards
drawn off and the residue then washed as before. In either case the
residual matter is afterwards well drained and then cast aside. The
bleaching liquor is stored in large tanks ready for use, from which
it is withdrawn as required by means of a syphon or otherwise.


=Bleaching with Chlorine Gas= (_Glaser's Process_).--This method of
bleaching is not so much adopted in England as formerly, but has
found much favour in Germany; indeed, within the past few years,
namely, in March 3rd, 1880, a process was introduced by Mr. F. Carl
Glaser for treating straw, in which, after boiling with caustic
soda as usual, the pulp is bleached by the action of chlorine
gas. The straw, after being separated from weeds by a slight or
superficial picking, is cut into pieces of from ⅓ to ⅔ of an inch
in length. The cut straw is then placed in a rotary boiler for
about four hours, at a pressure of about 4 to 4½ atmospheres, in a
solution composed of 29 lbs. of caustic soda at 71°, and 48 lbs.
of calcined soda at 90°, rendered caustic, for every 220 lbs. of
straw. After boiling, the dirty ley is drawn off, and the boiled
straw subjected to two washings with water. It is then conveyed
to the washing-engine, where it is washed for an hour; the drum
of the machine should have a sieve or sifter, the apertures
of which are about 60 to the square inch. The washed straw is
next dried by centrifugal force in a hydro-extractor, until it
contains about 70 per cent. of water, which is necessary for the
action of the chlorine gas. To effect this, so as to obtain not
very solid or close cakes of straw, the holes of the wire of the
hydro-extractor should not be more than 50 to the square inch.
The cakes of straw thus formed are then exposed to the action
of chlorine in leaden chambers of the ordinary kind, in which
they are placed in layers upon hurdles, or upon shelves. If the
chlorine is produced by hydrochloric acid, for every 220 lbs. of
unboiled straw, 51½ lbs. of the acid at 20° B., and a corresponding
quantity of 70 per cent. peroxide of manganese are used. After
the bleaching operation, the acid formed is removed by washing in
a washing-engine. If a complete reduction of the fibres has not
been effected by the bleaching, this may be completed by the aid
of well-known machines, and either before or subsequent to the
after-bleaching there is used for 220 lbs. of straw about 4½ lbs.
of chloride of lime, at 35° [per cent.?] The patentee then gives
the following explanation:--"As pine wood or fir is chemically
freed from its colouring principle and transformed into fibres as
well as cellulose, the object of the intense action of the chlorine
is to destroy the mucilage of the straw, as well as the incrusting
matters which have not been destroyed by the boiling with caustic
soda, and consequently to strip or expose and open the fibres." It
will be readily seen that this process bears a close resemblance to
Mr. C. Watt's wood-pulp process.


=Electrolytic Bleaching= (_C. Watt, jun.'s, Process_).--At the
present time, when the means of obtaining the electric current for
practical purposes in the arts have so far exceeded that which
would have been deemed probable some forty years since, we find
that many ingenious processes, which were found to be unpractical
at that time from the want of cheap electrical power, have since
reappeared in the form of patented inventions, which would seem to
possess every merit--but originality.

So long ago as September 25th, 1851, the author's brother, Mr.
Charles Watt, obtained a patent for, amongst other claims,
decomposing chlorides of sodium and potassium, and of the metals of
the alkaline earths into hypochlorites by electricity. It may be
well to make a few extracts here from his specification in order
that some of the subsequent patents, to which we shall refer, may
be traced to what may, perhaps, be considered their true origin.
In the specification in question, the inventor says:--"The third
part of my invention consists of a mode of converting chlorides of
potassium and sodium, and of the metals of the alkaline earths,
into hypochlorites and chlorates, by means of a succession of
decompositions in the solution of the salt operated upon, when
induced by the agency of electricity.... Electricity first
decomposes the chloride, the chlorine being eliminated at one of
the electrodes, and the alkaline or earthy metallic base at the
other electrode.... The liberated chlorine will, when it is set
free, combine with a portion of alkali or alkaline earth in the
solution, and a hypochlorite will be formed. The hypochlorite thus
formed will, by the continued action of heat, be resolved partly
into a chlorate of the alkali or alkaline earth, and partly into
a chloride of the metallic base, and the chloride will again be
subjected to decomposition, and a hypochlorite formed.... If I
desire to produce a hypochlorite of the alkali or earth, I merely
keep the vessel warm ... and continue the process until as much
of the saline matter has been converted into a hypochlorite as
may be required for the purpose to which the solution is to be
applied. This mode of forming a hypochlorite of the alkalies and
alkaline earths may be used for preparing a bath for the purpose of
bleaching various kinds of goods, and the bath may be strengthened
[recuperated] from time to time by the action of the electric
current."

Thus it will be seen that this specification clearly described a
process by which the chlorides of sodium and potassium, and of the
metals of the alkaline earths (chloride of magnesium, for example),
may be converted into hypochlorites by electrolysis, and the
hypochlorite solution obtained used for the purposes of bleaching.
It would appear difficult to conceive how any subsequent patent for
accomplishing the same thing, and using essentially the same means,
can claim originality in the face of such "prior publication" as
was effected by the usual "Blue-book," which any person can buy for
eightpence.


=Hermite's Process.=--The following description of this process
has been furnished by the engineers engaged in connection with
the process to the _Paper Trade Review_:--"Briefly described,
the Hermite process consists in manufacturing a solution of high
bleaching power by electrolysing an aqueous solution of magnesium
chloride. The salt is decomposed by the current at the same time
as the water. The nascent chlorine, liberated from the magnesium
chloride, and the nascent oxygen, liberated from the water, unite
at the positive pole, and produce an unstable oxygen compound of
chlorine of very high bleaching power. The hydrogen and magnesium
go to the negative pole; this last decomposes the water and forms
magnesium oxide, whilst the hydrogen is disengaged. If in this
liquid coloured vegetable fibre is introduced, the oxygen compound
acts on the colouring matter, oxidising it. Chlorine combines with
the hydrogen to form hydrochloric acid, which finding itself in the
presence of magnesium in the liquid combines with it, and forms the
initial chloride of magnesium."


=Andreoli's Process.=--This process consists, avowedly, in
bleaching pulps "by means of hypochlorite of sodium, produced
by electrolytical decomposition of a solution of chloride of
sodium." In carrying out his process, M. Andreoli uses as an
electrolyte "concentrated or non-concentrated sea-water, or a
solution of chloride of sodium, the specific gravity of which
varies according to the quality and nature of the materials to be
treated. Generally the solution to be electrolysed works better
with a density of 8° to 12° B., but although salt is cheap, and the
solution when exhausted may be regenerated by passing an electric
current, I always endeavour to have when possible (_sic_) a weak
solution, and with some kinds of pulp an electrolyte having the
density of sea-water (3° B.) is sufficiently strong to bleach."

The foregoing are the only electrolytic processes for bleaching
fibres that need recording, and we fancy there will be little
difficulty in tracing the resemblance between the two latter and
the process of Mr. C. Watt.


=Thompson's Process.=--This process, for which a patent was
obtained on February 3rd, 1883, may be thus briefly described:--In
bleaching linen fabrics the material is boiled for about three
hours in a solution of cyanide of potassium or sodium--about
half an ounce of the salt to each gallon of water--to remove the
resinous matter from the fibre, so that the cellulose may be
exposed to the action of the bleach. The fabric is then washed,
and again boiled for three hours more in a similar solution, and
after being again washed is ready for bleaching. With cotton the
preliminary boiling is not necessary, unless the material is
greasy, in which case a solution of half the strength and two
hours' boiling is sufficient. In ordinary cases cotton is not
boiled at all, but is simply washed in cold water and squeezed.
In bleaching, all vegetable fibres are treated in the same way,
the only difference being in point of time. The cotton or linen,
after being treated as described, is then piled somewhat loosely
in an air-tight vessel, 9 lbs. of cloth to the cubic foot of space
being considered sufficient. The vessel is then filled with a weak
solution of bleaching liquor, consisting of about one ounce of dry
bleaching powder to each gallon of water. "After the vessel has
been filled, the liquor is immediately run out, and is replaced
by an atmosphere of carbonic acid, which quickly liberates the
chlorine on the fibre, and thus decomposes the water, uniting with
the hydrogen and liberating the oxygen, the result of which, is
to bleach the fibre or fabric. In about an hour the whole of the
bleaching liquor in the fibre will have been thus decomposed, and
this operation must be repeated until the material is of the proper
whiteness to be withdrawn from the action of the chlorine. The
material is then washed and squeezed. Chlorine, however, always
leaves these materials of a yellowish white." To remove this tint,
the material is passed through a solution of oxalic acid--about 2
oz. to the gallon--squeezed as it passes out of this solution, and
then passed through another solution made by dissolving ¼ grain
of triethyl rose aniline to the gallon of water, or 20 grains
of indigo, as may be preferred. To this solution oxalic acid is
added until it becomes of an opaque but bright turquoise blue. The
material, after washing, is then white.

The patent describes and illustrates the apparatus to be used
in conjunction with certain parts of existing apparatus used in
bleaching.


=Lunge's Process.=--In this process acetic acid is used in place
of hydrochloric or sulphuric acids, etc., to set free the chlorine
or hypochlorous acid, in the ordinary method of bleaching with
hypochlorite of lime, or bleaching powder, which, the inventor
says, "combines all the advantages of the materials formerly
employed, without any of their drawbacks.... The price is no
impediment, for a minimal quantity is sufficient, the same being
regenerated over and over again. At first acetic acid and chloride
of lime decompose into calcium acetate and free hypochlorous
acid. In the bleaching process the latter yields its oxygen,
hydrochloric acid being formed. The latter instantly acts upon the
calcium acetate; calcium chloride is formed and acetic acid is
regenerated, which decomposes a fresh quantity of chloride of lime,
and so forth. Consequently the smallest quantity of acetic acid
suffices for splitting up any amount of chloride of lime.... The
hydrochloric acid formed is never present in the free state, as it
instantly acts upon the calcium acetate. This is very important,
since hydrochloric acid weakens the fibre by prolonged contact,
whilst acetic acid is quite harmless. Since there are no insoluble
calcium salts present, the operation of 'souring' after bleaching
is quite unnecessary; this not merely saves the expense of acid,
and of the subsequent washing of the fabrics, but it also avoids
the danger, especially present in the case of stout fabrics, of
leaving some of the acid in the stuff, which concentrates on drying
and weakens the fibre; it may also prove injurious in subsequent
dyeing operations. But in the new process no free acid is present
except acetic acid, which has no action upon fibre, even in its
concentrated state and at a high temperature."

The acetic acid may be employed in various ways, including the
following:--A small quantity of the acid may be added from the
first to the bleaching liquor; or the fabric, after being treated
in the ordinary way with a solution of the bleaching powder, may
be steeped, without previous washing, in water containing a little
acetic acid; or the fabric may be steeped in water acidulated with
acetic acid, and bleaching liquor afterwards run in slowly and
gradually, with continuous agitation in the usual way. In the case
of hard water, or of impure bleaching liquors, a good deal of the
acetic acid would be consumed in neutralising the lime; in this
case, some hydrochloric or sulphuric acid may be added, but only
sufficient for the purpose, so that no acid but hypochlorous or
acetic acid exists in the free state. The process is applicable to
the bleaching of vegetable fibres, whether spun or in the unspun
state, and for bleaching paper pulp made from rags, wood, straw,
esparto, etc. Besides acetic acid, any other weak organic acid of
an analogous nature may be used.


=Zinc Bleach Liquor.=--Strong acids are often objectionable for
liberating chlorine from bleaching powder, and especially in
bleaching some classes of paper pulp. If a solution of sulphate
of zinc be added to one of bleaching powder, sulphate of lime is
precipitated, and the zinc hypochlorite formed at once splits up
into zinc oxide and a solution of free hypochlorous acid. Chloride
of zinc acts similarly; for a saturated solution of zinc in
hydrochloric acid decomposes as much bleaching powder as half its
weight of concentrated oil of vitriol.--_Varrentrapp._ Consequently
zinc salts can be employed in place of sulphuric acid, and thus
bleach the paper pulp very quickly. When this mixture is employed
in bleaching pulp, the precipitated sulphate of lime resulting from
the reaction and also the oxide of zinc formed, remain in the pulp,
and serve as loading materials.


=Alum Bleach Liquor.=--Orioli[19] recommended for use, in
paper-mills especially, a bleach liquor made by decomposing
equivalent quantities of a solution of chloride of lime and
sulphate of alumina, formerly known as _Wilson's Bleach Liquor_.
Sulphate of lime is precipitated, and hypochlorite of aluminium
remains in solution; this being a very unstable salt can be applied
for bleaching without the addition of an acid, splitting up into
aluminium chloride and active oxygen. Consequently the liquid
always remains neutral, and the difficulty caused by the obstinate
retention of free acid in the fibre, by which it is strongly acted
upon in drying, in this case does not exist. The aluminium chloride
also acts as an antiseptic, so that the paper stock may be kept for
many months without undergoing fermentation or other decomposition.
The solution is allowed to act for about ten minutes in the
engine.--_Lunge._


=New Method of Bleaching.=--Young's Paraffin Oil Company have
recently introduced what they term an "intermediate oil for
paper-making," to be used with alkali in the boiling of rags and
esparto, for the purpose of increasing the bleaching power of
the powder, and producing a softer pulp, at the same time having
no smell. Several well-known paper-makers have tried, and speak
favourably of it. The quantity of oil to be added to the caustic
varies for different stock, but may be said to average about 1½
gallon per ton.[20]



CHAPTER X.

_BEATING OR REFINING._

  Beating.--Mr. Dunbar's Observations on Beating.--Mr. Arnot on
  Beating Engines.--Mr. Wyatt on American Refining-Engines.--The
  Beating Engine.--Forbes' Beating-Engine.--Umpherston's Beating
  Engine.--Operation of Beating.--Test for Chlorine.--Blending.


=Beating.=--One of the most important operations in the manufacture
of first-class paper is that of _beating_, by which the half-stuff
becomes reduced to a fine state of division, and the fibres which,
in the condition of half-stuff, are more or less loosely held
together in a clotted state, become separated, and are thus put
into a condition in which they will intertwine with each other, or
_felt_, as it is termed, when submitted to the vibratory motion
of the wire-cloth of the paper machine. The beating-engine, or
beater, as it is commonly called, much resembles in construction
the washing- and breaking-engine, but since it is required to still
further reduce the pulp to a condition suitable for paper-making,
the knives of this engine are more numerous and are made to revolve
more rapidly. In this engine the half-stuff is cleansed from
bleach, hydrochloric or sulphuric acid--whichever acid may have
been used in the bleaching--chloride of calcium, and the various
products resulting from the decomposition of the chloride of lime.
In this engine, also, the loading, sizing, and colouring materials
are worked up with the pulp, and the stuff fully prepared for its
final transfer direct to the paper-machine. Before describing
the various forms of beating-engines which have been from time
to time introduced, including some of the most recent types, to
which special attention will be drawn, we purpose quoting some
observations of well-known experts in paper manufacture which will
be read with interest, since they fully explain the importance that
attaches to the proper manipulation of the beating-engine for the
production of paper of high quality.


=Mr. Dunbar's Observations on Beating.=--There is no operation of
the paper-mill that requires more careful attention and experienced
judgment than that of beating, or refining, to bring the pulp to
the finest possible condition for paper-making; in this department,
Mr. Dunbar urges, "none but thoroughly efficient men should be
employed, for it is here that the paper is really made--that is,
the quality of the paper produced at the paper-machine will be
in proportion to the treatment the material has received; and if
the half-stuff sent to the beating-engines is not subjected to
judicious manipulation and careful preparation for the special
paper to be made, all future doctoring will prove unsatisfactory."


=Mr. Arnot on Beating Engines.=--On this subject Mr. Arnot
says:--"Upon the management of the beating-engine the character of
the paper produced largely depends. What is wanted is not a mincing
or grinding of the fibre, but a drawing out or separation of the
fibres one from another; in fact, the name of the machine indicates
pretty accurately the nature of the action required--beating.
Long, fine fibres can only be produced [obtained] by keeping the
roll slightly up off the bed-plate, and giving it time to do
the work. Sharp action between the roll and the bed-plate will,
no doubt, make speedy work of the fibre, but the result will be
short particles of fibre only, which will not interlace to make a
strong felt. Indeed, the action I refer to will reduce the long,
strong fibre of linen to little better than that of wood or straw.
Practice and careful observation can alone make a good beater-man,
and for the finer classes of paper none but careful, experienced
men should be entrusted with the management of the beating-engine.
Sometimes the operation is conducted in two successive engines,
the first being called the intermediate beater, but I have hitherto
failed to see wherein the advantage of this system lies. The time
usually occupied in beating esparto for printing-paper is about
four hours, while for rags the time may vary from four to twelve
hours, or even more." This, however, depends upon the nature of the
rags themselves, and the purposes to which they are to be applied.


=Mr. Wyatt on American Refining-Engines.=--Referring to the
engines adopted in America, Mr. Wyatt says:--"There are various
modifications of the original Jordan, the principal ones being
the Marshall, Jeffers, and improved Jordan; but I gathered that
experience proves the Jordan type to be the most practical and
efficient in the end, and is one of the most generally used.
One Jordan is required for each machine, refining all the stuff
supplied to it. The roll, or plug, runs from 350 to 400 revolutions
per minute, the horse-power consumed varying from 25 to 40
horse-power according to the work done, and an engine will do up to
1,000 lbs. of pulp per hour. The time saved in the beating-engine
by the use of the Jordan is just about one-third of what would
otherwise be necessary, that is to say, pulp requiring otherwise
six hours beating only takes four hours if finished in the Jordan.
The half-beaten pulp is emptied into a stuff-chest, and the Jordan
is furnished with a small stuff-pump and service-box, just as at
the paper-machine what the Jordan does not take flows back again
into the chest: the pulp from the Jordan is run into the ordinary
machine stuff-chests. The finished pulp can be taken from the
Jordan at three different levels from the circumference of the
roll, or plug. If the pulp is wanted 'free,' it is drawn from the
bottom of the engine; if wanted 'wet,' or well greased, it is drawn
from the top; and if medium from the centre."


=The Beating-Engine.=--The ordinary form of beater consists of a
cast-iron trough 13 feet 6 inches long × 6 feet 6 inches wide, and
the bottom is dish-shaped, so as to prevent the pulp from lodging,
which would inevitably be the case if the bottom were flat, as the
pulp would be apt to lodge in the angles formed by the junction of
the bottom with the vertical walls of the trough. The iron trough
is fitted with a cast-iron roll, 3 feet 6 inches × 3 feet 6 inches,
which is provided with 69 "roll-bars," or knives, arranged in 23
groups of 3 bars each; this roll is suspended upon a malleable iron
shaft 5 inches in diameter, resting upon side levers; suitable
gearing is attached by which the roll can be lifted or lowered at
will, the action being uniformly equal on both sides, by which the
knives of the roll are kept uniform with those of the bed-plate
beneath. The bed-plate, furnished with 20 steel knives, of the
same length as the roll, is placed immediately beneath the roll.
When the knives of the bed-plate are straight they are fitted into
the plate-box at an angle, but in some cases they are bent at a
slight angle, when they are termed _elbow plates_. There have
been, however, many improvements in the beating-engine introduced
of late years, some of which are of considerable importance, and
to some of these we will now direct attention. Although our own
manufacturers have introduced improvements in beaters which have
been fully recognised by the trade, the American engineers have
not been behindhand in devising modifications which appear to
have some important advantages. The Jordan beater, which has been
extensively adopted in the States, consists of a roll in the form
of a truncated cone, furnished with knives in the usual way; this
revolves in a box of a similar form, fitted with knives in the
direction of its length, but at slightly different angles. In this
engine the stuff enters at the narrow end through a box having an
arrangement which regulates its flow, and the pulp is discharged
by several openings in the cover at the wider end. In an engine
invented by Mr. Kingsland there is a circular chamber furnished
with knives covering its sides; between this is a circular plate,
also fitted with knives, which revolves. The stuff enters through
a pipe in the centre of one of the sides of the chamber, and flows
out through an opening in the opposite side.


[Illustration: Fig. 21.]

=Forbes' Beating Engine.=--This engine, an illustration of which
is given in Fig. 21, is manufactured by Bertrams, Limited, of
St. Katherine's Works, Edinburgh. The engine has three chambers,
two rolls, and a mixing wheel; the rolls, only one of which is
uncovered in the engraving, are fixed in the outer channels,
and the mixing wheel is placed in the middle channel. By this
arrangement the pulp flows alternately into the two outer channels,
and after passing through the rolls again it enters the centre
channel at the opposite end.


[Illustration: Fig. 22.]

=Umpherston's Beating Engine.=--This engine, for which a patent
was granted in 1880, has been successfully adopted at the _Daily
Chronicle_ and other mills, and presents several important
advantages, one of the chief being that it occupies much less
ground space than ordinary beating-engines. Indeed, we have heard
it remarked of this engine that it will do double the amount of
work in the same ground space as the ordinary engine, and this,
in some mills, would be a decided advantage. The construction
of this beater, a drawing of which is shown in Fig. 22, is thus
described by the patentee:--"In the common and almost universal
form of engines used for preparing pulp for paper-making, the
pulp travels horizontally in a trough with semi-circular ends,
and straight sides, partly divided longitudinally by a partition
called the midfeather, around which the pulp flows from the back
of the roll to its front, where it passes under the roll and over
the bottom working-plate, and is again delivered over the back
fall to pass again round the midfeather to the front of the roll.
In the course of these repeated revolutions part of the pulp near
the circumference of the tub has much farther to travel than the
part near the midfeather, and consequently is not so often operated
upon, and the pulp is thus unequally treated. As an improvement
upon this form of tub, I make it so that the pulp passes from the
back of the roll to its front through a longitudinal passage under
the back fall, the pulp thus moving as through an inverted syphon,
the superincumbent weight of the semi-fluid pulp, as delivered
over the back fall of the roll, pressing it along this passage and
upwards, to enter again in front of the roll. The roll A, bottom
plate B, and the form of the back fall C, are similar to those
of ordinary engines, but the trough is formed with the passage D
under the bottom plate B, so that the semi-fluid contents of the
engine, in travelling from the back fall C to the front of the roll
A, pass by means of the passage D under the bottom plate B in the
direction indicated by the arrows, the superincumbent weight of
the semi-fluid pulp, as it is delivered over the back fall C at
the back of the roll A, pressing it along the under passage D and
upwards to the front of the roll A. The position of a drum-washer
is shown at E, and at F is seen a section of the cross shaft for
raising or lowering both ends of the roll A simultaneously; G is
the roll cover, which may be of any usual form. By this invention
the semi-fluid pulp is acted upon in a more effective manner, and
its particles are also more equally treated than has hitherto been
the case."

[Illustration: Fig. 23.]

[Illustration: Fig. 24.]

The beating-engines are usually driven from a separate engine, but
Messrs. Bertrams have introduced a system of direct driving for
these engines by which, it is said, there is a considerable saving
in power. The accompanying engravings, Figs. 23 and 24, show a
series of eight beaters, each carrying 300 lbs. of pulp, driven by
one of their compound direct-driving steam-engines, and now being
worked at the Forth Paper Mills.


=Operation of Beating.=--Having referred to some of the more
important improvements connected with the beating-engines, we will
proceed to explain the operation of beating as briefly as possible.
The bleached half-stuff is removed from the tray of the press in
caked masses, and in this condition is conveyed in trucks or boxes
to the beating-engine. The first thing to be attended to is the
removal of the last traces of chlorine from the pulp, which, if
not effectually done, would cause injury to the size, and also
corrode the strainer plates and wire-gauze of the paper-machine.
It is possible to wash out the chlorine by an abundant application
of pure water, but this method of removing the chlorine is very
tedious and occupies a long time, while it also involves the use
of enormous quantities of water--a serious consideration in some
mills; to this may be added the still more important fact that
by the method of washing out the chlorine a considerable loss of
fibre takes place. The plan most usually adopted is to neutralise
the chlorine left in the pulp by the application of suitable
chemical agents, whereby the chlorine is rendered inert. These
agents, technically termed "antichlors," are sometimes objected
to, however, although they are in themselves practically harmless
so far as their action upon cellulose is concerned. Mr. Arnot,
who has considered this subject very thoroughly, says:--"I do not
think there is much in this objection, as those agents that are
soluble pass through the wire of the machine almost completely,
while those that are insoluble are in the finest possible state of
division and pearly white. The chemical agent most largely used is
hyposulphite of soda, but hyposulphite of lime is also employed,
and those agents, known by the name of 'antichlor,' are put into
the engine in such a quantity as will ensure the neutralisation
of the whole of the chlorine. The products of the reaction, when
the soda salts are used, are chloride of sodium (common salt) and
sulphate of soda (Glauber's salt), and, when the lime salt is used,
chloride of calcium and sulphate of lime, the latter identical with
the pearl hardening so well known as a loading agent." From this
it will be seen that little or no harm can possibly occur either
to the fibre or the metal work of the machine by the employment of
the neutralising agents named, and when it is borne in mind that
the simple washing of the pulp would occupy the beating-engine
for a lengthened period and exhaust a considerable quantity of
water--which, as we have said, would in some mills be a serious
matter--the adoption of the neutralising method would undoubtedly
have the preference.

The engine, being partly filled with water, is set in motion, and
the bleached half-stuff introduced in small quantities at a time,
each portion being allowed to become thoroughly mixed with the
water before the next batch is added. The charging of the beater
with half-stuff is kept up until the mass becomes so thick that it
will only just move in the trough under the action of the revolving
roll. If the beater is of the older type, portions of the pulp
are liable to lodge in corners, to remove which the "beater-man"
uses a wooden paddle, with which tool he also pushes the slowly
moving pulp in the direction of the roll, especially when the stiff
mass appears to move too slowly. At this stage the neutralisation
of the chlorine in the pulp is effected, which is done by adding
a solution of hyposulphite of soda, a little at a time, until
the liquor ceases to redden blue litmus paper, strips of which
should be dipped into the pulp every few minutes until the paper
persistently retains its blue colour. This operation should be
conducted with great care, so as to exactly neutralise the traces
of chlorine without adding an excess of the hyposulphite of soda.
Besides this salt, other substances are used as "antichlors," as,
for example, hyposulphite of lime, which is prepared by boiling
milk of lime (slacked lime made into a thin mixture with water) and
flour of sulphur in an iron vessel until the latter is dissolved,
when, after cooling and settling, the resulting solution, which
is of an orange-yellow colour, is ready for use. One great
objection to the use of hyposulphite of lime, however, is that when
decomposed by the chloride of lime remaining in the pulp sulphur
is set free, which, mingling with pulp, will impart to it a yellow
tint; besides this, in passing over the drying cylinders of the
machine the sulphur present in the paper may attract oxygen from
the air, converting it into sulphuric acid, which must inevitably
prove injurious to the manufactured paper. Sulphite of soda has
also been used as an antichlor, and is said to be preferable to
hyposulphite of soda,[21] inasmuch as the latter salt is liable to
decompose with the liberation of free acid, which is not the case
with the sulphite of soda.


=Test for Chlorine.=--Instead of relying solely upon the litmus
paper test when applying the antichlor, the following test for
chlorine may also be used with advantage:--Take 2 drachms (120
grains) of white starch, and make it into a paste with a little
cold water; then pour over it about half a pint of boiling water,
stirring briskly; to this add 1 drachm of iodide of potassium,
and stir until dissolved and well incorporated with the starch
solution. The mixture is then to be allowed to cool, when it is
ready for use. A few drops of this mixture dropped upon a small
sample of the pulp will indicate if any chlorine be present by the
spot assuming a blue colour; if such be not the case, the pulp may
be considered free from chlorine.

During the beating, the roll, which should make not less than 220
revolutions per minute, is lowered, a little at a time, so that
the cutting edges of the bars and plate may be brought together
gradually and equally until the pulp is reduced to the desired
condition. The pulp is made long or short according to the quality
of paper to be produced; news papers, which require strength, are
made of long-fibred pulp, while writing paper, or paper of fine
texture, is made of shorter pulp. The stuff should be what is
called "mellowed" in the engine, which is effected by a judicious
working of the roll, not lowering it suddenly but gradually, and
not much at one time, on the plate, until the pulp attains the
fineness required. This is generally arrived at in about three and
a half to four hours, though sometimes the beating of pulp from
rags is continued for more than double that time. It should be
added that if the cutting edges of the roll and plate are brought
together suddenly and too closely, the fibre will be cut, and as a
consequence the paper produced will be tender.

Esparto, which, in the process of boiling becomes reduced to
such a soft condition that the fibres may be readily separated
by the fingers, does not require such excessive beating as rags;
indeed, the perfect disintegration of the fibres of esparto is
practically accomplished in about half the time occupied by rags,
and often much less, but this of course depends upon the nature
of the esparto itself and upon the thoroughness of the boiling.
Wood pulps also require but moderate beating, since the process of
disintegration is generally pretty effectually accomplished by the
processes to which the raw material is subjected in the course of
manufacture into half-stuff, which is the condition in which this
paper material is furnished to the manufacturer.


=Blending.=--To produce papers of the different qualities required
by the trade, a system of blending is adopted, which may be
effected--(1) by mixing the materials in the raw state, or the
rags, previous to boiling; and (2) blending the half-stuff in
the beating-engine. The latter method, however, is generally
preferred. Sometimes, also, pulps of different character are beaten
separately and then mixed in the stuff-chests, where they are mixed
as thoroughly as possible before passing on to the machine, but
this method would be less likely to ensure a perfect mixture of
the respective pulps than would be effected with proper care in
the beater. The proportions of the several materials to be blended
is also a matter of important consideration. In blending esparto
with rag stuff, if the former be in excess it becomes reduced
to the proper condition before the latter is sufficiently fine,
which causes the rag fibre to appear in "knots and threads" in the
manufactured paper. But if the rag stuff be allowed to predominate,
the beating is conducted as though no esparto were present, by
which, while the rag stuff becomes reduced to the proper length of
fibre, the esparto, which is still further reduced, in mingling
with the longer fibre of the rags forms what is called a "close"
paper. Mr. Dunbar, in his useful little work, "The Practical
Paper-maker," furnishes a series of receipts for blending for
high-class papers, as also the proportions of colouring matter to
be used, which the reader will do well to consult. For news papers,
esparto and straw pulps are generally used, in varying proportions
according to the nature and quality of the esparto; these
proportions have to be regulated according to the judgment of the
paper-maker, and vary greatly at different mills. A large quantity
of sulphite and other wood pulps are also used, those coming from
Scandinavia and Germany being especially suited to the requirements
of the English manufacturer. Mechanical wood pulp is also used in
a moderate degree--sometimes up to 15 per cent., in some English
mills, but it is said that in Germany this paper stock is sometimes
used to the extent of 90 per cent.



CHAPTER XI.

_LOADING.--SIZING.--COLOURING._

  Loading.--Sizing.--French Method of Preparing Engine
  Size.--Zinc Soaps in Sizing.--Colouring.--Animal or
  Tub-Sizing.--Preparation of Animal Size.--American Method of
  Sizing.--Machine-Sizing.--Double-sized Paper.--Mr. Wyatt's
  Remarks on Sizing.


=Loading.=--The very finest qualities of paper are usually made
without the addition of any _loading_, as it is called, but for
most other papers more or less loading material is added, according
to the quality of paper to be produced. The loading material used
for ordinary qualities is kaolin, or china clay, and for the better
qualities sulphate of lime or _pearl hardening_, as it is termed in
the trade. China clay, as it occurs in commerce, is in the form of
soft lumps and powder, is nearly white, and when rubbed between the
finger and thumb should present no hard particles of gritty matter.
To prepare it for mixing with the pulp it is first worked up into a
thin cream with water, which is usually done in a vessel furnished
with an agitating arrangement by which the clay becomes intimately
mixed with the water. The cream is then strained through a fine
sieve to separate any impurities present, and is then allowed to
flow into the beating-engine containing the stuff while in motion,
by which it soon becomes mingled with the pulp. The proportion of
china clay or other loading material which is to be introduced into
the pulp depends upon the quality of the fibre and the requirements
of the manufacturer, some makers using less of the material than
others. From 3 per cent. to 10 or 15 per cent. appears to be about
the extreme range for employing the material as a necessary
ingredient, in the production of various classes of paper, above
which figures the addition of loading material may be considered as
an adulteration. Sometimes nearly twice the largest amount named is
employed, no doubt to meet the exigences of keen competition--from
foreign sources especially.

One effect of the loading, whether it be china clay or sulphate
of lime, is to close the pores of the paper, whereby a smoother
surface is obtained, while at the same time, if the material has
been used in proportions suited to the quality of the fibre, and
not in immoderate excess, a stronger paper is produced. A species
of asbestos termed _agalite_ has been introduced as a loading
material, and since it has a fibrous texture, it blends with the
fibres of the pulp, forming, as it were, a vegeto-mineral paper. It
is stated that as much as 90 per cent. of the agalite used in the
beating-engine enters into the manufactured paper, while not much
more than half the china clay used is held by the pulp.


=Sizing.=--"Engine sizing," as it is termed, consists in adding
certain ingredients to the pulp while in the beating-engine. The
materials generally used are alum and resin soap, in proportions
suitable to the paper to be produced. Resin soap is formed by
boiling ordinary resin in a jacketed pan such as is used by
soapmakers for preparing small quantities of fancy or other soaps,
with a solution of soda crystals in the following proportions:
Resin, 16 lbs.; soda crystals dissolved in water, 8 lbs.; and the
boiling is kept up for about two hours, or until a soap is produced
which is perfectly soluble in water. The method of preparing this
soap as conducted at the soapworks has been described in the
author's work on soap-making,[22] p. 64, from which the following
abstract is taken: "Put into a pan capable of holding about 12
gallons, 2¼ gallons of fresh caustic soda ley at 30° B. Apply
gentle heat, and when the ley begins to boil throw in, every few
minutes, in small quantities at a time, finely powdered and sifted
resin until 37 lbs. have been introduced. The mixture must be well
stirred the whole time to prevent the resin from 'clogging' and
adhering to the pan. It is important to moderate the heat, as the
resin soap has a great tendency to expand and an excess of heat
would cause it to boil over. The heat, however, must be kept to
near the boiling point, otherwise the mass will become thick and
of a very dark colour. When kept at near the boiling point it is
always clear and its colour of a reddish yellow. If, during the
boiling, the resin soap rises and threatens to overflow, the heat
must be checked by throwing in a little cold water, only using
sufficient to effect this object. It is absolutely necessary to
stir the mass continually, otherwise the resin will agglomerate in
masses and thus prevent the alkali from acting freely upon it. The
boiling takes about two hours, when the soap is run into an iron
frame and allowed to cool. It is very important that the resin used
is freed from particles of wood, straw, etc., for which purpose it
should be passed through a tolerably fine sieve."

Respecting the preparation of resin soap, Davis says:--"The
proportion of resin used to each pound of soda ash varies in
different mills, 3, 4, or even 5 lbs. of resin being used to each
pound of soda ash. The proportion of resin, soda ash, and water,
can be best determined by practical experience, as no prescription
could be devised which would be suitable to every case." M.
d'Arcet, who modified the proportions recommended by M. Bracconot,
recommends for the preparation of resin soap--

  Powdered resin                                    4·80 parts.
  Soda crystals at 80° (French, alkalimeter)        2·22   "
  Water                                           100      "

Theoretically speaking, only 2·45 parts of alum would be required
to precipitate the resin; but the waters, which are almost always
calcareous, neutralise part of the alum. Crystals of soda are
much more expensive than soda ash, but on account of their greater
purity they are sometimes preferred to the latter. At the present
day the resin soap is preferably made by dissolving ordinary
resin with a solution of carbonate of soda under boiling heat in
a steam-jacketed boiler, the class of paper to be made governing
the quantity of resin to be employed. The boiling usually requires
from two to eight hours, according to the relative proportions of
soda ash and resin used--the greater the proportion of soda used
the less time is required for boiling--the process being completed
when a sample of the soap formed is completely soluble in water....
About 3 lbs. of resin to 1 lb. of soda is the usual proportion. The
resin soap is cooled after boiling by running it into iron tanks,
where it is allowed to settle, the soap forming a dense syrup-like
mass, and the colouring matters and other admixtures of the resin
rising to the top are easily removed. It is important to run off
the mother liquor (ley) containing the excess of alkali, for when
the soap is used it consumes the alum to neutralise it."

When the impurities and ley have been removed the soap is dissolved
in water, and if, from imperfect boiling, a portion of the resin
is found not to have been saponified, a small quantity of a strong
solution of soda crystals is added to the water used for dissolving
the soap.

Where starch is used for stiffening purposes, the soap is mixed
with a quantity of starch paste in the proportion of 1½ part of
starch to 1 part of resin soap. Some manufacturers, Mr. Davis
states, mix the starch paste with the kaolin in lieu of mixing
it with the resin soap. In either case the materials should be
thoroughly strained before being added to the pulp. From 3 to 4
lbs. of the mixture of resin soap and starch paste to each 100
lbs. of dry pulp are about the proportions in which the size is
generally used, but the quantity added to the pulp in the beater
depends upon whether the paper is to be soft-sized or hard-sized.

Sizing is chiefly applied to papers which are to be written upon
with ordinary inks, and also, with a few exceptions, to printing
papers, the object being to close the pores of the paper and render
it non-absorbent, by which the spreading or running of the ink is
effectually prevented. While the finest lines may be written upon a
well-sized paper (as ordinary writing paper, for example) without
spreading in the least degree, a similar stroke of the pen upon
blotting paper, tissue, or unsized printing paper would spread in
all directions, owing to the highly absorptive property of the
cellulose.

The sizing of the pulp is conducted as follows:--After the
loading material has been introduced and well mixed, the resin
soap, previously dissolved in water, a little carbonate of soda
being sometimes added, is mixed with a paste of starch prepared
by dissolving starch in boiling water, and the mixture of soap
and starch is then passed through a fine sieve to keep back
any particles or lumps that may be present. The proportion of
the materials used in sizing vary at the different mills, each
manufacturer having formulæ of his own; about 1 part of resin size
to 3 of starch paste, and, say, from 9 to 12 lbs. of the mixture,
may be used for 300 lbs. of pulp; and, if preferred, the respective
ingredients may be put into the engine separately, a method adopted
at some mills. Some manufacturers of the finest papers, instead of
dissolving the starch in hot water, make it into a thin paste with
cold water, in which condition it is introduced into the pulp, the
object being to impart to the paper a particular feeling to the
touch which is not obtainable by other means.

The mixture of resin size and starch paste, with or without the
addition of water, is added to the pulp in the beater, in which
the pulp is circulating, and the engine allowed to run until the
materials are well incorporated in the pulp. At this stage a
solution of alum (about 28 to 30 lbs. for 300 lbs. of pulp), or
of sulphate of alumina,[23] is introduced, which causes the resin
soap to become "separated," the sulphuric acid of the alum uniting
with the alkali of the soap and setting the resin and alumina
free in the form of minute particles; the resin in the subsequent
drying on the calenders becomes fused, as it were, and thus cements
the fibres and alumina together, at the same time rendering them
non-absorbent and improved in whiteness by the precipitated
alumina. Sometimes ordinary soap is added to the resin soap, which
is said to impart a higher finish to the paper in the operation of
calendering.

The so-called "concentrated alum," which contains a higher
percentage of sulphate of alumina than the crystallised alum,
is considered the most economical in use, being proportionately
cheaper, and the variety known as "pearl alum" is specially
recommended. "Aluminous cake" is another preparation which has
found favour in many mills, but since it sometimes contains a
large excess of free sulphuric acid it requires to be used with
caution, since this acid, although it will brighten the colour of
some aniline dyes, will discharge the colour from others, while
at the same time it may injuriously affect the brass-wire cloths
of the paper machine. The alum solution should be prepared in a
lead-lined tank, fitted with a steam pipe for heating the contents
when required.

The proportions of the materials used in sizing differ considerably
in different mills, but the following may be taken as an average
for common writing and printing papers:--

  Per 100 parts of dried pulp 10 to 12 parts of resin.
   "        "        "        20  " 30   "      starch.
   "        "        "        10  " 12   "      alum.

To the sizing solution is generally added from 30 to 50 parts
of kaolin. When a colour is present on which alum would have a
prejudicial effect this is usually replaced by about one-third of
its weight of sulphate of zinc. Many mineral substances have from
time to time been added to paper stock, principally to increase its
weight, and in 1858 Sholl took out a patent for adding carbonate
of lime, a substance which, however, had long been fraudulently
used in order to increase the weight, but he found it to have
the property of fixing the ink in the pores of the paper, thus
rendering it immovable. The only useful addition is kaolin, or some
similar aluminous compound, as it attaches itself to the fibre,
and, while giving the required opacity and a good surface, takes
both printing and writing ink well, and has the advantage, from a
manufacturer's point of view, of increasing the weight. It has been
proposed that small quantities of glycerine be added to the pulp,
in order to give the paper greater flexibility, and especially to
give copying-paper the quality of taking up colour readily.[24]


=French Method of Preparing Engine Size.=--Thirteen pails of water
are boiled in a copper-jacketed pan capable of holding about 150
gallons; 90 lbs. of soda crystals are then introduced and allowed
to dissolve, when 200 lbs. of finely-powdered resin are gradually
introduced, with constant stirring, and the boiling is sustained
for about two hours after the last portion of resin has been added.
A further addition of water is now made by putting in five pails
of cold water, and the water is then boiled for an hour and a half
longer. The resin soap is then transferred to stock-chests, in
which it is allowed to remain for ten days or longer, fresh batches
being prepared in rotation, to meet the requirements of the mill.

To determine whether an excess of resin soap or of alum has been
added to the pulp, red and blue litmus papers should be employed,
the former turning blue if an excess of resin soap be present, and
the latter red when alum or sulphate of alumina is in excess. For
uncoloured papers the aluminous material should be added until the
pulp becomes faintly acid, which will be indicated by the blue
litmus paper turning slightly red when immersed in the pulp.

Besides resin soap, various substances have been proposed as sizing
materials, including wax dissolved in a strong solution of caustic
soda and precipitated with alum, but the cost would be an objection
to the use of this material except for the highest classes of
paper. It is stated that 12 lbs. of gum tragacanth to each 500 lbs.
of resin has been used in preparing some kinds of engine-sized
papers, and is said to impart to them an appearance equal to that
of tub-sized papers.


=Zinc Soaps in Sizing.=--According to a paragraph in the
_Papermakers' Monthly Journal_, a somewhat novel method of sizing
is employed in Germany, which consists in the precipitation in the
stock of zinc soaps. Cottonseed oil soap or Castille soap is worked
up in the engine with the stuff, and after it has become well
mixed with the pulp a solution of sulphate of zinc is added, which
results in the formation of a white and heavy zinc soap, which is
insoluble, and adheres well to the fibres. The weight and whiteness
of the zinc soap are the main points in favour of this method,
which is said to yield good results.


=Colouring.=--The pulp, after passing through the various processes
described, although apparently white, invariably presents a yellow
tinge when converted into paper. To obviate this it is usual to
"kill" the yellow tint by adding to the pulp small quantities of
blue and pink colouring matters. The blue colours generally used
are ultramarine, smalts, and various aniline blues, and the pinks
are usually prepared from cochineal, either in a liquid form or as
"lakes" (compounds of cochineal and alumina) or aniline dyes, the
former being preferable, as it is not injuriously affected by the
alum used in sizing. The ultramarine should be of good quality,
otherwise it will become decomposed, and its colouring property
destroyed by the action of the alum, but more especially so if
the alum contains an excess of free acid. Smalts blue, which is a
kind of coloured glass, is not affected by acids. In preparing the
colouring matters for mixing with the pulp they must first be mixed
with water, and the liquid should then be strained, to keep back
any solid particles that may be present in the material. Aniline
blues should be dissolved in hot water, or alcohol, and then
diluted. Samples of the pulp are examined from time to time until
the desired effect is produced, which the practised eye of the
beater-man can readily determine.


=Animal or Tub-sizing.=--Another process of sizing, termed
"animal-sizing," "tub-sizing," or "surface-sizing," is also
adopted in the manufacture of certain classes of paper, and is
either accomplished by hand or on the machine. The former method
having been elsewhere described (p. 132) we will now describe the
operation of sizing on the machine, to which the term tub-sizing is
also applied. The size employed, which is prepared from what are
called "glue pieces," or clippings of "limed" and unhaired skins of
animals, requires to be as colourless as possible, in order that
the colour of the paper may not be injuriously affected by it.


=Preparation of Animal Size.=--This operation is generally
conducted at the mill, the materials from which the size is
produced being the cuttings or parings of animal skins and hides,
or _pelts_, which have undergone the processes of "liming" and
unhairing preparatory to being tanned. The cuttings, or _pates_,
commonly called "glue pieces," are first soaked in a mixture of
lime and water, placed in large tubs for several days, after which
they are put into a wooden cylinder, or drum, five or six feet
in diameter, and about ten feet in length, which revolves upon
a horizontal shaft, which, being hollow, admits the passage of
water to the interior of the drum. The drum is perforated, and
revolves in a large tank, while a continuous stream of water is
allowed to pass through it, and the dirty water escapes through
the perforations in the drum. When the cuttings are sufficiently
cleansed in this way, they are transferred to an iron copper,
furnished with a false bottom and steam-pipe, or a jacketed pan.
The cuttings are next covered with water; steam is then turned
on, and the liquid brought to a temperature below boiling point,
or say, about 180° to 190° F., it being very important that the
liquid should not actually boil. This operation is carefully kept
up for twelve to sixteen hours, according to the nature of the
cuttings, by which time all the material excepting any membranous
or fatty matters that may be present, will have become dissolved
and a solution of gelatine obtained. The liquor is then allowed
to settle for a short time to allow fatty matters to rise to the
surface and membranous substances to deposit, and the fatty matters
must afterwards be carefully removed by skimming. The liquor should
next be strained to separate any floating particles of a membranous
character. Sometimes the gelatine solution is clarified by adding
a small quantity of powdered lime, which is thoroughly mixed by
stirring, after which it is allowed to rest. When it is found that
the impurities and lime deposit too slowly, a little weak sulphuric
acid is added, which, forming an insoluble sulphate of lime, the
solid matters quickly subside, leaving the liquor quite clear.
The solution is next filtered through felt, and is afterwards
treated with a solution of alum, which at first causes the liquid
to thicken and become nearly solid, but it becomes fluid again,
however, on the addition of more alum solution. When this condition
is finally attained, the liquid is ready for use in the process of
sizing. The addition of the alum (which should not contain any free
acid) to the gelatine greatly improves its sizing property, besides
preserving it from decomposition. The treatment of the glue pieces
for the purpose of obtaining gelatine solutions is fully described
in the author's work on "Leather Manufacture," p. 401.[25]


=American Method of Sizing.=--Another method of preparing size,
and which is adopted in America, is the following:--In large paper
mills the size is generally prepared in a room devoted to the
purpose, and is commonly situated near the machine. The finest
grades of light hide and skin clippings are used for No. 1 letter
papers, but less costly stock is employed for the lower grades of
animal-sized papers. To preserve the glue pieces the tanners and
tawers macerate the clippings in milk of lime and afterwards dry
them. As the clippings require to be freed from the lime, the first
treatment they receive at the paper-mill is to put them in large
wooden tubs partly filled with water, in which they are allowed to
soak for several days. They are afterwards more perfectly cleansed
by means of a drum-washer, such as we have before described. Fresh
hide and skin clippings, that is, those which have not been limed
and dried at the tanneries, and which are occasionally purchased
by the paper manufacturers, require to be used as soon as possible
after they arrive at the mill as they readily decompose, and are
placed in tubs partly filled with water, in which 2 per cent. by
weight of caustic lime has been dissolved. The pieces, if from
calfskins, are allowed to remain in the lime bath for ten to
fifteen days, clippings of sheepskins fifteen to twenty days, and
trimmings from heavy hides, as ox, etc., twenty-five to thirty
days, the milk of lime being renewed once or twice a week, and
the material well stirred from time to time. The glue-stock, as
it is sometimes termed, is afterwards thoroughly washed in the
drum-washer, and when this operation is complete the material is
spread out in the yard to drain, and when sufficiently dried is
ready for boiling, or may be stored until required for use.

To prepare size from the material treated as described, it is
placed in a boiler of cast or wrought-iron or copper, furnished
with a perforated false bottom, and capable of holding from 100
to 400 lbs. of the raw material, according to the requirements of
the mill. Several such boilers may be placed close to each other.
At the bottom of the boiler is a stop-cock for drawing off the
gelatine solution when required. When the requisite charge of
glue-stock has been introduced into the boiler, water is poured
over it and steam turned on, which passes through a pipe fixed
beneath the false bottom, and care is taken that the temperature
of the contents of the boiler should not exceed 200° F., which
heat is kept up for ten to eighteen hours, according to the
nature of the materials treated. The gelatine solution is drawn
off from the boiler as it is formed, into wooden tubs, and at the
same time carefully strained to remove membranous matters and
suchlike impurities. Several boilings are made from the same batch
of glue-stock, and all the solutions are afterwards mixed together
in the receiving tubs, and a solution of alum is added in such
proportions as to be recognised by tasting the liquor. One object
in adding the alum being to prevent the gelatine from decomposing,
more of this substance should be added in warm than in cold weather.

When the solutions are cool they are ready for use, and the
gelatine is removed from the receiving tubs and dissolved in a
separate tub as required for use, the dissolving tub being provided
with a steam-pipe. The proportion of water--which should only be
lukewarm--used in dissolving the gelatine varies from a quarter to
half the bulk of the latter, the nature of the fibre and thickness
of the paper regulating the proportion of water to gelatine, the
strength of the size liquors being greater for thin papers and weak
fibres than for thick papers and strong fibres.

The operation of sizing is considered one of the most difficult
and uncertain with which the paper-maker has to deal, since the
material (gelatine) is greatly influenced by the conditions of the
atmosphere, both as regards its temperature and humidity, while
the temperature of the liquid size itself has also an important
influence on the success of the operation. The condition of
the paper, again, also affects the result, for if it be highly
porous it will probably be weak, and consequently there may be
considerable waste during the process of sizing from the necessary
handling it is subjected to; moreover, should the paper have
been blued with ultramarine, a strongly offensive odour is often
imparted to it; this, however, may be obviated by employing fresh
size and drying the paper as completely as possible. There are two
systems of animal-sizing employed at the mill, namely, hand-sizing
and machine-sizing, which is also called tub-sizing, the former
being applied to papers of the finest quality. Papers that have
been made by the machine, after being cut into sheets, are
hand-sized, as described in the next chapter.


=Machine-Sizing.=--The lower-priced papers, to be machine-sized,
are first partly dried over a few cylinders, after which the paper
passes through a tank containing liquid size, from whence it passes
between two rollers, which squeeze out the superfluous size; it is
then wound on to a reel on which it remains some time to enable the
size to thoroughly permeate the paper, after which it is wound on
to another reel, and from thence it passes over a series of wooden
drums or cylinders, each of which is furnished with a revolving
fan; by this means the paper becomes dried slowly, whereby a more
perfect sizing of the material is effected.


=Double-Sized Paper.=--This term is applied to paper which, after
being sized in the engine in the usual way, is afterwards "surface
sized," as it is called, with animal size in the manner described.

Respecting the drying of paper after it has been tub-sized there
seems to be some difference of opinion as to whether it is best
to hang it in a loft to dry or to dry it over the cylinders of a
drying machine. Upon this point the New York _Paper Trade Journal_
makes the following remarks:--"When the paper is passed through
the size-tub, it is again wet; the fibres expand, and their hold
on each other is relaxed. Now it must make a difference to the
subsequent strength and quality of this paper whether it be hung
up in a loft to dry or run over a drying machine. If it is hung in
the loft no strain is put upon it and the fibres are at liberty
to shrink, or slowly contract, in all directions; whereas if it
is run over a drying machine, consisting of from 50 to 100 reels,
the longitudinal strain prevents the fibres from shrinking and
reassuming their normal position in that direction. Attempts have
been made to obviate this defect by regulating the speed of each
section of the machine in such a manner as to allow for the
shrinking, but this only remedies the evil by preventing the paper
from breaking as it travels over the machine. Everything else being
equal, it would seem that loft-dried paper must be superior to that
dried over the drying machine. Our home manufacturers endorse this
view, inasmuch as they continue to prefer the system of loft-drying
to the less expensive machine methods."


=Mr. Wyatt's Remarks on Sizing.=--Mr. James W. Wyatt, in a
paper on the "Art of Paper-making,"[26] makes the following
observations on engine-sizing and animal-sizing which will be
read with interest:--"Engine-sizing renders the paper fully as
non-absorbent as animal size. The latter penetrates the sheets only
slightly and forms a coating or skin on each surface, whereas the
engine size surrounds each fibre and impregnates the whole mass.
Surface-sizing, however, produces a stronger, firmer sheet, and is
smoother for the pen to travel over; the manufacturer also gets
the benefit in the price of the paper of the additional weight of
the size, amounting to 7 per cent. on the average. On the other
hand, as the animal size is mostly a skin on the surface, if the
coating be broken anywhere by the use of a knife in scratching,
the paper will only imperfectly resist ink in that place, a great
disadvantage for account and office-books and ledgers. Engine-sized
paper is much cheaper to produce than animal sized, and is
therefore used principally for the lower qualities of writings and
for almost all kinds of printings where firmness and smoothness is
not so much a desideratum. Most tub-sized papers have a certain
portion of engine size mixed with the pulp. This not only ensures
the thorough sizing of the sheet, but also is a measure of economy
in reducing the absorbing power of the paper for the animal
size. Papers for ledgers and office-work are best given an extra
proportion of engine size to ensure their ink-resisting properties,
and they are also sized by hand in animal size and loft dried." The
following rough estimate of the comparative cost in materials and
wages of engine-sizing and animal-sizing paper may be of interest:

  Engine-sizing, per 20,000 lbs.:--

                             £  s.  d.
      Materials              5   2  0
      Wages                  0  12  6
                            ----------                   d.
           Total            £5  14   6  Cost per lb. = 0·068
                            ==========

  Animal-sizing, per 20,000 lbs.:--

                             £  s.  d.
      Materials             36   0  0
      Wages                  4  10  0
                           -----------
           Total           £40  10  0
                           ===========



CHAPTER XII.

_MAKING PAPER BY HAND._

  The Vat and Mould.--Making the Paper.--Sizing and Finishing.


Under the old system of making paper by hand, the rags were
reduced to a fine state of division by a process of _retting_, or
slow putrefaction. The rags were first washed in water, and then
piled in heaps, in which condition they were allowed to remain
until they became tender, that is, readily pulled asunder by the
fingers. During the decomposition the rags not unfrequently became
rotten in some portions of the heaps, thus involving considerable
loss of fibre. The rags were next placed in a strong chest, in
which iron-shod stamping rods were fitted, and these by their
continued action gradually reduced them to a pulp. The stampers
were eventually superseded by the beating-engine, the invention
of a Dutchman, which received and still retains the name of the
"Hollander." Other machines, as the duster, washing and breaking
engines, and the beating engine, have entirely taken the place of
the older system, which required the work of forty pairs of stamps
for twenty-four hours to produce one hundredweight of paper.


=The Vat and Mould.=--The pulp being prepared, is conveyed from
the beaters to the working vat, where it is diluted with water.
The vat is a wooden or stone vessel about 5 feet square and 4
feet deep, being somewhat wider at the top than at the bottom. A
steam-pipe is supplied to the vat, so that the pulp and water may
be heated to a convenient temperature for working, and an agitator
is also furnished to keep the pulp and water uniformly mixed. The
mould in which the pulp is raised from the vat to form a sheet of
paper, consists of a wooden frame, neatly joined at the corners,
with wooden bars running across, about 1½ inch apart, and flush
with the top edge of the frame. Across these again, in the length
of the frame, wires are laid, about fifteen or twenty in an inch,
which are placed parallel to each other. A series of stronger
wires are laid along the cross-bars, to which the other wires are
fastened; these give to what is termed "laid" paper, the ribbed or
"water-marked" lines noticeable in hand-made paper. Upon the mould
is fitted a movable frame, called the _deckle_ or _deckel_, which
must fit very neatly or the edges of the paper will be rough. The
mould and deckle form together a kind of shallow tray of wire.
Sometimes the mould is divided by narrow ribs of wood, so that two
or four sheets of paper may be made in one operation. Connected
with the vat is a slanting board, called the _bridge_, with copper
fillets attached lengthwise upon it, so that the mould may slide
easily along the bridge.


=Making the Paper.=--When preparing for work, the vat-man stands
on one side of the vat, and has on his left hand a smaller board,
one end of which is fastened to the bridge, while the other rests
on the side of the vat. An assistant, called the _coucher_, is at
hand, whose duty it is to handle the frames or moulds containing
the pulp after they have passed through the hands of the vat-man or
maker. The latter now takes in his hand a mould, and lays it upon
the deckle; he then dips the mould, with its deckle in its proper
place, into the vat of agitated pulp, and lifts up as much of the
pulp as will form a sheet of paper. This, as will be readily seen,
requires the greatest dexterity, since the workman has nothing
but his sense of feeling to guide him. It is said, however, that
practice gives him such a nicety of feeling in this respect that
he can make sheet after sheet of the largest-sized drawing papers
with a difference in weight of not more than one or two grains in
any two of them. Great skill is also required to hold the mould in
a perfectly horizontal position, otherwise during the felting and
settling of the pulp the sheet of paper would be thicker on one
part than another. The mould being held lengthwise, that is, with
the long parallel wires running from right to left hand, he gives
the mould a gentle shake from his chest forward and back again,
which is called the _fore-right shake_; this shake takes place
across the wires, not in the direction of their length. He next
gives a shake from right to left, and back again, the respective
movements thus propelling the pulp in four directions. The vat-man
now pushes the mould along the small board on his left, and removes
the deckle, which he connects to another mould and proceeds to
form another sheet of paper, and so on. The coucher, taking the
first mould in hand, turns it upside down upon a piece of woollen
felt-cloth, then removing the mould, he takes another piece of
felt and lays it over the sheet and returns the mould by pushing
it along the bridge to the vat-man, when he receives in return a
second mould to be treated as before.

In the above way felts and paper are laid alternately until a
pile of six or eight quires is produced, which is afterwards
submitted to pressure in a very powerful press. When sufficiently
compressed, the machine is relaxed, and the felts are then drawn
out, on the opposite side, by an operative, called a _layer_, who
places the felts one by one upon a board, and the sheets of paper
upon another board. The coucher then uses the felts again for
further operations. Two men and a boy only are employed in this
part of the work. In the evening all the paper made during the
day is put into another press, and subjected to moderate pressure
to obliterate the felt marks and expel a further portion of the
water. On the following day the paper is all separated, which is
called _parting_, again pressed, and is then transferred to the
drying-loft. The drying is effected by suspending the sheets of
paper upon a series of ropes, attached to wooden supports; ropes
of cow-hair are used for the purpose, as this material does not
stain the paper.


=Sizing and Finishing.=--When the paper is dry, it is taken down
and laid carefully in heaps ready for sizing, which is the next
operation to which the paper is subjected. The preparation of the
size from animal skins, etc., is described in Chapter XI. When
preparing to size the paper, the workman takes several quires of
the paper, and carefully spreads the sheets out in the liquid size,
which is placed in a large tub, taking care that each sheet is
uniformly moistened before introducing the next. The superfluous
size is afterwards pressed out, and the paper then "parted" into
separate sheets, which are again subjected to pressure, and finally
transferred to the drying-room, where they are allowed to dry
slowly. When dry, the paper is conveyed to the finishing-house, to
be again pressed and looked over by women, who, being furnished
with small knives, pick out knots and other imperfections and
separate the perfect from the imperfect sheets. The paper is now
again pressed, and then handed to the finisher, to be counted into
reams and packed, the reams being afterwards pressed and finally
tied up and conveyed to the warehouse for sale. When the paper is
required to be hot-pressed, this is done by placing each sheet of
paper alternately between two smoothed sheets of pasteboard, and
between each group of fifty pasteboards is placed a hot plate of
iron, and the pile then submitted to heavy pressure, whereby the
surface of writing paper acquires a fine, smooth surface.



CHAPTER XIII.

_MAKING PAPER BY MACHINERY._

  The Fourdrinier Machine.--Bertrams' Large Paper
  Machine.--Stuff Chests.--Strainers.--Revolving Strainer
  and Knotter.--Self-cleansing Strainer.--Roeckner's Pulp
  Strainers.--The Machine Wire and its Accessories.--Conical
  Pulp Saver.--The Dandy Roll.--Water Marking.--De la Rue's
  Improvements in Water-marks.--Suction Boxes.--Couch Rolls.--
  Press Rolls.--Drying Cylinders.--Smoothing Rolls.--Single
  Cylinder Machine.


=The Fourdrinier Machine.=--It is just ninety years since Louis
Robert, a Frenchman, devised a machine for making a continuous
web of paper on an endless wire-cloth, to which rotary motion was
applied, thus producing a sheet of paper of indefinite length.
The idea was subsequently improved upon by Messrs. Fourdrinier,
who adopted and improved upon M. Robert's machine, and with the
valuable aid of Mr. Bryan Donkin, a young and gifted machinist,
in the employ of Mr. Hall, engineer, of Dartford, constructed a
self-acting machine, or working model, in 1803, which, from its
effectiveness and general excellency of workmanship, created
at the time a profound sensation. This machine was erected at
Frogmore, Hertfordshire; and in 1804 a second machine was made
and put up at Two-Waters, Herts, which was completely successful,
and the manufacture of continuous paper became one of the most
useful and important inventions of the age. From that period the
"Fourdrinier," with some important improvements introduced by Mr.
Donkin, gradually, but surely, became established as an absolutely
indispensable machine in every paper-mill all over the world.
Although the machine has been still further improved from time to
time, those of recent construction differ but little in principle
from the original machine. An illustration of the machine is shown
in Fig. 25, the detailed parts of which are expressed on the
engraving.


=Bertrams' Large Paper Machine.=--The principal aim in the
construction of the paper-making machine has been to imitate, and
in some particulars to improve, the operations involved in the
art of making paper by hand, but apart from the greater width
and length of paper which can be produced by the machine, the
increased rapidity of its powers of production are so great that
one machine can turn out as much paper in three minutes as could
be accomplished by the older system in as many weeks. The drawing
represents the modern paper-machine as manufactured by Bertrams,
Limited, who supplied one of these machines to Mr. Edward Lloyd,
for the _Daily Chronicle_ Mill, at Sittingbourne, which runs a
wire 40 feet long by 126 inches wide, this being, we believe, the
largest and widest paper-machine in the world. It is provided with
20 cylinders, chilled calenders, double-drum reeling motion, with
slitting appliance for preparing webs to go direct to the printer's
office without the assistance of a re-reeling machine, and is
driven by a pair of coupled condensing steam-engines. On our recent
visit to Mr. Lloyd's mill we were much struck with the excellent
working of this splendid machine.

In the illustration, as will be seen, there are two sets of
drying cylinders, while small cylinders, or felt drying-rolls,
from 16 to 24 inches in diameter, are introduced to the felts of
the cylinders, before the smoothing-rolls, which discharge the
moisture with which the felts are impregnated from the damp paper,
whereby a considerable saving in felts is effected. Messrs. Bertram
state that the highest speed yet attained has been by their own
machinery, and is 270 feet of paper per minute.

[Illustration: Fig. 25.]

The progress of the pulp after it leaves the beating-engines for
conversion into paper may be described as follows:--The valve at
the bottom of the beating-engine is opened, when the pulp flows
through a pipe into the stuff-chests, which are generally situated
below the level of the engines. The beaters are then rinsed with
clean water to remove any pulp that may still cling to them, the
rinsing water passing also into the stuff-chests.


=Stuff-chests.=--These are large vessels of a cylindrical form, so
that the pulp may have no corners to lodge in, and are generally
made of wood, though sometimes they are made of cast-iron plates
bolted together. The chests are of various dimensions, according
to the requirements of the mill, being usually about 12 feet in
diameter and 6 feet deep, having a capacity for 1,000 to 1,200
lbs. of stuff. To keep the pulp well mixed in the stuff-chest,
of which two are usually employed for each machine, a vertical
shaft, carrying two horizontal arms, each extending nearly across
the interior of the chest, are provided, which are only allowed
to revolve at a moderate speed, that is, about two or three
revolutions per minute, otherwise the pulp would be liable to work
up into knots, and thus form a defective paper. Motion being given
to the shaft, the rotating arms keep the pulp and water uniformly
mixed, at the same time preventing the pulp from sinking to the
bottom of the stuff-chest.

The pulp is next transferred to a regulating box, or "supply box,"
by means of a pump called the _stuff-pump_. The regulating-box,
which has the effect of keeping a regular supply of pulp in the
machine, is provided with two overflow pipes, which carry back to
the stuff-chests any superfluous pulp that may have entered them,
by which the stuff in the regulating-box is kept at a uniform
level, while the machine is supplied with a regular and uniform
quantity of the diluted pulp. The stuff-pump conveys the pulp
through a valve in the bottom of the regulating-box in a greater
quantity than is actually required, the superfluity returning
to the stuff-chests by the overflow pipes; thus the supply-box,
being always kept full, furnishes a regular and uniform supply
of pulp to the sand-tables, or sand-traps as they are sometimes
called. _Sand-tables_ are large wooden troughs, varying in size at
different mills, but Mr. Dunbar gives the following proportions for
a first-class sand-trap; namely, 14 feet long by 8 feet wide, and 8
inches deep. The bottom of the trap is covered with felt, sometimes
old first-press felt being used, and is divided into several
compartments by thin bars of lead or iron, or strips of wood, which
keep the felt in position, and also retain any particles of sand
or other heavy solid matter that may be accidentally present in
the pulp. For the purpose of diluting the pulp for the machine,
there is, attached to the inlet of the sand-traps, a box with
two supply-taps, one for the delivery of pulp, and the other for
water; and these being turned on, the pulp and water flow over the
sand-traps, and the diluted pulp then falls into the strainers,
which, while allowing the fine pulp to pass freely, keep back all
lumps of twisted fibre, and particles of unboiled fibre, which
latter, if not removed, would appear as specks on the surface of
the finished paper.


=The Strainers= are formed of brass or bronze plates, in which are
cut a very large number of narrow slits, which gradually widen
downward, so as to prevent the pulp from lodging. Each plate has
about 510 slits, and several plates, connected together by bolts,
constitutes the complete strainer. When in use, the strainer
receives a jogging motion, which is communicated to it by means of
small ratchet wheels keyed on shafts passing beneath the machine;
this causes the fibres to pass more freely through the slits. There
are many different forms of strainers, which have been the subject
of numerous patents. It will be sufficient, however, to give one or
two examples of improved strainers which have been more recently
adopted by manufacturers.


[Illustration: Fig. 26.]

=Revolving Strainer and Knotter.=--The revolving strainer, which
was invented by the late senior partner in the firm of Messrs. G.
and W. Bertram (now Bertrams, Limited), has since been extensively
adopted, and the present firm have introduced a patent knotter
in conjunction with the apparatus, the complete arrangement of
which is shown in Fig. 26. The standard size for these revolving
strainers is 7 feet long by 18⅜ inches wide on each side of the
four surfaces. The vats are of cast iron, and the apparatus is
supplied with driving gear, bellows, regulating boxes and spouts,
as necessary. The firm also supply these strainers with White's
patent discs, and Annandale and Watson's arrangement. A A are two
revolving strainers, as applied to the paper-machine, showing
gearing for strainers and bellows. B is the patent knotter as used
for two strainers. C is the counter-shaft overhead. D D is the back
shaft of the machine, and E E the wire of the paper-machine.


[Illustration: Fig. 27.]

=Self-cleansing Strainer.=--The same firm also introduced this
form of strainer, an illustration of which is given in Fig. 27. The
action of the strainer is described as follows:--

The pulp flows on to the strainer at A, and passes away through
the pipes B B. At C is a valve for the discharge of waste pulp.
The strainer plates have an inclination of about 1 inch in the
direction of their length, and in those which are nearest to A,
where the pulp enters, the slits are wider, the knots being pushed
forward by the energy of the flow. The vacuum pumps, D D, are
worked from the shaft E. The tubes F F are for supplying water to
the plates, by which the coarser particles of the pulp are pushed
forward, and the slits are thus kept clean. The strainer will pass
from 18 to 20 tons of the finest paper per week.


[Illustration: Fig. 28.]

[Illustration: Fig. 29.]

=Roeckner's Pulp Strainers.=--This invention consists in
constructing boxes, with one or both ends open, forming the
strainers, fixed, or to slide in or out, so as to be readily
cleaned. One or more fans are fitted in these boxes, and are put in
motion from the outside, so as to cause what is called "suction"
through the strainers. One or a number of such boxes are fixed
into a vat, the open ends discharging the pulp which has passed
through the strainers to the paper-machine, and can be so arranged
that all the fans are worked on one shaft. The vat may be divided
into compartments, so that the stuff flows from one to the other.
Instead of boxes, the strainers may be formed of tubes, in which
suitable slits or perforations have been provided. The tubes will
be perfectly closed at one end, and the strained pulp, after
passing through them, will be delivered to the paper-machine from
their open ends, which may fit into a ring, so that when cleaning
is required they may be easily lifted out or in. The suction is
provided inside these tubes by the fans, which are oscillated by
suitable gear from the outside of the vat. The strainers may,
instead of being stationary, be attached to the fans and oscillate
with them, in which case the open ends would have to be attached
to the vat by an indiarubber or cloth ring, or the strainers may
oscillate whilst the fans are stationary. Any number of these
strainers may be fixed into vats, disposed vertically or otherwise.
In the vat A, Fig. 28, which receives the pulp to be strained,
are several tubes, _p p p_, with one end open, having slits in
them similar to strainer plates. Inside of these are two, three,
or more plates, _f f f_, Fig. 29, running the full length of the
tube fixed to the shafts, _s s s_, and to the sides of the tubes,
which serve as fans, besides giving strength to the tubes. The
shafts _s s s_ are carried in bearings at each end, and have each
one end projecting through, upon which are keyed levers, _h h
h_, which, being connected to a rod _r_, worked by an eccentric,
_e_, at the end, gives an oscillating motion to the tubes and
fans. Any number of tubes may be in the vat, and may either work
separately or divided. With several tubes it is preferable to have
them arranged as shown in the drawing by division plate _d_, so
that the accumulated "knots," &c., may flow finally into the end
compartment (which will form an auxiliary strainer), and may be
mixed with more water, so that the fine pulp still contained in
the stuff can flow away through the slits and the knots, &c., be
taken out when necessary. The tubes should be placed so far apart
that a workman can get his hand between. The closed ends work free
in the stuff, while the open ends run through indiarubber sheet or
other material, fitted so well to the tube that the fibre can only
get through the slits of the tube to flow on to the paper-machine
through the channel at side by the sluice _v_. The arrows indicate
the direction of the flow of pulp.

[Illustration: Fig. 30.]

Mr. Dunbar says, "the straining power necessary to pass and clean
pulp in an efficient manner for 25 tons of finished paper per week
is two revolving strainers, consisting of four rows of plates, or 7
feet by 18 inches of straining surface on each of the four sides,
the plates being cut No. 2½ Watson's gauge."

After passing through the strainers the pulp should be absolutely
free from knots or objectionable particles of any kind, and in a
proper condition for conversion into paper.


=The Machine Wire and its Accessories.=--On leaving the strainers
the pulp passes into a vat, in which is a horizontal agitator,
which causes the pulp and water to become well mixed, and ready to
flow on to the endless wire-cloth of the machine. The wire-cloth is
made of exceedingly fine wire, the meshes ranging from 60 threads
and upwards to the inch, there being sometimes as many as 1,900
holes per square inch, but the meshes usually employed run from
2,000 to 6,000 per square inch. The ends of the cloth are united by
being sewn with very fine wire. The width of the wire-cloth varies
considerably, the greatest width being, we believe, that supplied
for the large machine at Mr. Edward Lloyd's mill at Sittingbourne,
which is 126 inches. The length of the wire-cloth is generally from
35 to 40 feet, the latter being considered preferable. Beneath the
wire is placed a shallow box called the "save-all," which receives
the water as it flows through the wire cloth from the pulp. In
order to effect a further saving of pulp which escapes through the
meshes of the wire-cloth, a machine called a "pulp-saver" is used
at some mills, through which the backwater, as it leaves the box or
save-all referred to, is passed.

The wire-cloth is supported by a series of brass tube rolls, which
are so placed as to render the layer of pulp on the wire absolutely
uniform, by which a regular thickness of the finished paper is
ensured. The wire is attached to a malleable iron frame, having a
sole-plate of cast iron, and carries a brass or copper breast-roll,
18 inches in diameter, a guide-roll 7 inches in diameter, and four
brass or copper rolls 5 inches in diameter under the wire, with
shafts extending through the rolls, and furnished with brass bushes
and brackets, and a self-acting guide upon the 7-inch guide-roll.
The tube-rolls or "carrying tubes" are carried upon brass bearings.
Attached to the sole-plate of the wire framing are three cast-iron
stands on each side for supporting the save-all beneath the wire.
To regulate the width of the paper there is on the top of the wire
a set of brass "deckles," carried on a brass frame passing over the
first suction box, of which there are two, and supported on the
wire frame by iron studs fixed in the frame. At each end of the
deckle-frame is a pulley for carrying the deckle-strap, with three
similar pulleys for expanding it. The deckle-frame is furnished
with two endless straps of india-rubber, these straps keeping the
pulp to the width required for forming ledges at the sides of the
web.


[Illustration: Fig. 31.]

=The Conical Pulp-saver=, which is shown in Fig. 31, was invented
by the late Mr. George Bertram and Mr. Paisley, and is manufactured
by Bertrams, Limited. Its use is to extract fibres from the washing
water before going into the river or otherwise. For the water
from the drum-washer, washing and beating engines, and for the
water from the paper-making machine, save-all, &c., it has proved
itself of great utility. It is simple in construction, small in
cost, takes up little room, and is easily repaired. When placed to
receive the washings from the beaters or paper-machine, the pulp
saved, if kept clean, can always be re-used. A is a conical drum
which is covered with wire-cloth, and it is made to revolve slowly
by suitable gearing. The water enters by the pipe B, which is
perforated, as shown, and passes through the meshes of the gauze,
while the pulp gradually finds its way to the wider end of the
drum, where it escapes into the box C, and can be conveyed again to
the beating-engines.


[Illustration: Fig. 32.]

[Illustration: Fig. 33.]

=The Dandy-roll.=--When it is required to produce a design or name,
termed a _water-mark_, upon the paper, this is done by means of a
roll called the _dandy-roll_, which consists of a skeleton roll
covered with wire-cloth, upon which the design is worked by means
of very fine wire. If the paper is required to be alike on both
sides, without any specific pattern or name upon it, the roll is
simply covered with wire-cloth, the impressions from which upon the
moist pulp correspond with those of the machine-wire on the under
surface. By this means paper known as "wove" paper is produced. A
dandy-roll of this character is shown in Fig. 32. "Laid" paper,
as it is termed, is distinguished by a dandy-roll having a series
of equidistant transverse wires on the upper surface of the wire
cylinder, as shown in Fig. 33, the effect of which is to produce
parallel lines on the paper, caused by the pulp being thinner where
the moist paper is impressed by the raised wires, which renders the
lines more transparent than the rest of the paper. The dandy-roll,
which is usually about 7 inches in diameter, corresponds in length
to the width of wire on which it rests, and is placed over the
wire-cloth between the suction-boxes. The journals of the roll
turn in slits in two vertical stands, one behind the machine frame
and the other in front of it. The roll, however, rests with its
whole weight on the wire, and revolves by the progressive motion
of the wire. The stands which support the roll prevent it from
being influenced by the lateral motion of the wire. By thus running
over the surface of the pulp when the wire is in motion, this roll
presses out a considerable quantity of water, at the same time
rendering the paper closer and finer in texture. Dandy-rolls of
various lengths, and bearing different designs or patterns, are
kept at the paper-mills, and great care is exercised to preserve
them from injury.


=Water-Marking.=--Dr. Ure describes the following processes
for producing a design for a line water-mark:--1. The design
is engraved on some yielding surface in the same way as on a
copper-plate, and afterwards, by immersing the plate in a solution
of copper sulphate, and producing an electrotype in the usual
way, by which all the interstices become so filled up as to give
a casting of pure copper. This casting, on being removed from the
sulphate bath, is ready for attaching to the wire gauze of the
dandy-roll. 2. The design is first engraved on a steel die, the
parts required to give the greatest effect being cut deepest; the
die, after being hardened, is forced by a steam hammer into some
yielding material, such as copper, and all of this metal which
remains above the plain surface of the steel is subsequently
removed by suitable means; the portion representing the design
being left untouched would then be attached to the wire-gauze
as before. Light and shade can be communicated to the mark by a
modification of the above process, for which purpose an electrotype
of the raised surface of a design is first taken, and afterwards
a second electrotype from this latter, which consequently will be
identical with the original surface. These two are then mounted
on lead or gutta-percha, and employed as dies to give impression
to fine copper-wire gauze, which is then employed as a mould. Thus
absolute uniformity, such as could not be attained by the old
system of stitching wires together, is now attained in bank-notes
by the adoption of the above method. It may be mentioned that when
the moulds were formed by stitching the fine wires together to
form a design, no less than 1,056 wires, with 67,584 twists, and
involving some hundreds of thousands of stitches, were required to
form a pair of £5 note moulds, and it was obviously impossible that
the designs should remain absolutely identical.

Sometimes water-marks are produced by depressing the surface of the
dandy-roll in the form of a design, which causes the paper to be
thicker where the design is than in the rest of the sheet of paper.
This modification was invented by Dr. De la Rue.


=De La Rue's Improvements in Water-marks.=--By one method, patented
in 1869, dandy-rolls, having a surface of embossed wire-gauze,
are used; the indentations in the gauze are inwards, causing a
thickening of the paper where they are brought in contact with
it. These thickenings correspond in form to the configuration of
the design or water-mark. The inventor has also affixed wire to
the surface of such dandy-rolls so as to form projections, in
order to thin the paper where the projections come in contact with
it, by which means light lines are obtained in the water-mark,
strengthening the effect of the thickened opaque design.

[Illustration: Fig. 34.]

By another patent, dated May, 1884, No. 8348, the inventor forms
the surface of the dandy-roll of wire-gauze embossed in such a
manner that parts of the surface of the gauze, corresponding to
the configuration of the design of the water-mark, are raised,
and project out from the general surface, and other parts
corresponding to the line shading of the design are depressed
below the level of the general surface. The accompanying drawing,
Fig. 34, shows diagrammatically, and greatly enlarged, a section
of a portion of the surface of a dandy-roll made in accordance
with this invention. _a_ represents the section of a ridge or
projection raised on the surface of the gauze; _b_ represents the
section of a groove or depression in the wire-gauze, which, with
other similar grooves, serves to produce an opaque shading to the
design. _c_ is an auxiliary ridge or projection, serving to define
the shading line, and to intensify it by driving the pulp into
the groove or depression _b_. Further effects may be obtained by
attaching wires to the dandy-roll, either in the usual way, where
the surface is unembossed, or upon the raised parts _a_, which
give the configuration to the water-mark. In place of forming the
ridges or projections _a_, which produce the configuration of the
water-mark, by raising portions of the wire-gauze above the general
surface, they may be formed by sewing on suitably shaped slips
of wire-gauze, or of sheet metal perforated all over with fine
holes, on to the surface of the gauze which is embossed with the
grooves _b_, but it is much to be preferred that both the ridges
_a_ and the grooves _b_ should be produced by embossing the gauze.
Water-marks may also be produced by placing sheets of finished
paper in contact with plates of copper or zinc, bearing a design in
relief, and submitting them to heavy pressure.


[Illustration: Fig. 35.]

=Suction-Boxes.=--These boxes, which are fitted under the wire,
are made of wood, and are open at the top, the edges being lined
with vulcanite. The ends of the boxes are movable, so that they
may be adjusted to suit the width of the paper required; they are
also provided with air-cocks for regulating the vacuum, which is
obtained by means of two sets of vacuum pumps, having three 6-inch
barrels to each set: a vacuum pump of this form is shown in Fig.
35. As the wire travels over these boxes, the action of the pumps
draws the wire upon them with sufficient pressure to render them
air-tight; by this means a large portion of the water which the
pulp still retains at this point becomes extracted, thereby giving
to it such a degree of consistency that it can stand the pressure
of the couch-rolls without injury. The backwater extracted by the
suction-boxes, as also that collected in the save-all, is added to
a fresh supply of pulp before it flows on to the sand-tables.


=Couch-Rolls.=--At the extreme end of the wire-cloth from the
breast-roll, and inside the wire, is the under couch-roll, from
which the wire receives its motion. This roll, which is of brass,
is usually about 14 inches in diameter, is carried upon a cast-iron
framing with brass bearings, and is ground to a working joint with
the top roll, which is also of brass, and 20 inches in diameter.
Both these rolls are covered with a seamless coating of woollen
felt. The upper roll rests upon the lower one, and the wire-cloth,
and the web of paper upon it, pass between the rolls, receiving
gentle pressure, by which the paper becomes deprived of more water,
rendering it still more compact. It is at this stage that the web
of paper leaves the wire-cloth, and passes on to a continuously
revolving and endless web of woollen felt, termed the "wet felt,"
from the moist condition of the paper. This felt, which is carried
on wooden rollers, is about 20 feet long, and is manufactured with
considerable care.


=The Press-Rolls.=--The paper now passes on to the _first
press-rolls_, which deprive it of a still further quantity of
water, and put it in a condition to bear gentle handling without
injury. The upper roll is fitted with a contrivance termed the
"doctor," which keeps the roll clean by removing fragments of paper
that may have become attached to it. The doctor is furnished with
a knife which passes along the entire length of the roll, pressing
against it from end to end. These rolls are generally of iron,
jacketed with brass, the under one being 14 inches in diameter, and
the top roll 16 inches. Sometimes this roll is made of fine-grained
cast-iron. When the roll is of iron the doctor blade is steel; but
when this roll is brass the knife is of the same material. The
under surface of the paper, which has been in contact with the
felt, and necessarily being in a moist condition, receives more or
less an impression from the felt over which it travelled, while the
upper surface, on the other hand, will have been rendered smooth
by the pressure of the top roll of the first press. To modify
this, and to render both surfaces of the paper as nearly uniform
as possible, the paper passes through another set of rolls, termed
the _second press-rolls_, in which the paper becomes reversed,
which is effected by causing it to enter at the back of the rolls,
which rotate in a reverse direction to those of the first press, by
which the under or wire side of the paper comes in contact with
the top roll of the press. By this arrangement the underside of
the paper is rendered equally smooth with the upper surface. The
second set of press-rolls is provided with an endless felt of its
own, which is usually both stronger and thicker than that used in
connection with the first press-rolls. In some mills each set of
press-rolls is provided with a doctor, to prevent the web of paper
from adhering to the metal. Sometimes the doctor knives are made
from vulcanite, a material which would seem specially suited for a
purpose of this kind. From this point the paper passes to the first
set of drying cylinders.


=The Drying Cylinders.=--The invention of the steam drying cylinder
is due to Mr. T. B. Crompton, who, in the year 1821, obtained a
patent for this useful addition to the paper-machine. Since that
period, however, the system of drying the paper by steam-heat has
been brought to a high state of perfection; not only this, but
the number of cylinders has gradually increased, while the heat
to which they are raised has proportionately decreased, and as
a consequence the size, which is injuriously affected by rapid
drying, is gradually deprived of its moisture, and thus renders
the paper closer and stronger, while at the same time a very rapid
speed can be maintained. The drying cylinders in the machine shown
in the engraving are 4 feet in diameter and 12 in number, being
arranged in two groups of 8 and 4 cylinders respectively, and in
the aggregate present a very large drying surface, it being very
important that the operation should be effected gradually, more
especially at its earlier stages. There is a passage between the
second press-roll and the cylinders, through which the machine-men
can pass from one side of the machine to the other. The first two
or three of the first section of cylinders are only moderately
heated, and having no felt on them, allow the moisture from the
paper to escape freely. The next five cylinders, however, are
provided with felts, which press the paper against the heated
surfaces, by which it becomes smooth and flattened, thus putting it
into a proper condition for passing between the _smoothing-rolls_.
The cylinders are heated by steam, and are generally of decreasing
diameter, to allow for the shrinking of the paper during the drying.


=Smoothing-Rolls.=--These consist of highly polished cast-iron
rolls, heated by steam. The paper being in a somewhat moist
condition when it passes through these rolls, they have the effect
of producing a fine smooth surface.

The paper next passes over the last four drying cylinders, all
being provided with felts, to keep the paper closely pressed
against their heating surfaces, by which the remaining moisture
becomes expelled and the paper rendered perfectly dry. The paper
now passes through the calender rolls, and is then wound on to
reels at the extreme end of the machinery. The operation of
calendering will be treated in the next chapter.


[Illustration: Fig. 36.]

=Single Cylinder Machine.=--For the manufacture of thin papers,
as also for papers which are required to be glazed on one side
only, a single cylinder machine, called the Yankee machine, has
been introduced, a representation of which is shown in Fig. 36.
It is constructed on the same principle as the larger Fourdrinier
machine up to the couching-rolls, when the paper leaves the
wire-cloth and passes on to an endless felt running round the top
couch-roll, and passes from thence to a large drying cylinder,
which is about 10 feet in diameter and heated by steam, the surface
of which is highly polished, giving to the surface of the paper
in contact with it a high gloss. There is attached to the machine
an arrangement for washing the felt for the purpose of cooling
and opening it out after passing through a cold press-roll and
the hot drying cylinder. This machine, as manufactured by Messrs.
Bentley and Jackson, for cap, skip, and thin papers, consists of
a rocking frame, and wrought-iron side bars, fitted with brass
bearings, the necessary brass and copper tube-rolls, couch-rolls,
with driving shaft, stands and pulley; self-acting wire guide,
brass deckle sides and pulleys, brass slice, vacuum boxes, pipes
and cocks; wet felt frame, with the necessary water pipes and
cocks, and carriages to carry the couch-rolls and felt-rolls; the
necessary wet felt-rolls and a felt washing apparatus; one bottom
press-roll carried by brass steps, and fitted with compound levers
and weight; one large cast-iron drying cylinder about 10 feet in
diameter, and fitted with a central shaft, steam admission and
water delivery nozzles, two water lifters and pipes, a manhole and
vacuum valve, a large spur driving wheel, spur pinion, driving
shaft and pulley; massive cast-iron framework, with pedestals to
carry the cylinder; traversing steel doctor and frames; copper
leading roll and carriages, a pair of reeling stands fitted with
brass steps, friction pulleys and plates, regulating screws, etc.;
a wooden platform and iron guard rail, all carried by strong
cast-iron framing; the necessary pulp and backwater pumps, shake,
knotter, stuff chests, service cistern, pipes and valves, shafting,
pedestals, change wheels, pulleys, &c. These machines can be
obtained of any desired width.



CHAPTER XIV.

_CALENDERING, CUTTING, AND FINISHING._

  Web-glazing.--Glazing Calender.--Damping-Rolls.--Finishing.--
  Plate Glazing.--Donkin's Glazing Press.--Mr. Wyatt on American
  Super-calendering.--Mr. Arnot on Finishing.--Cutting.--Revolving
  Knife Cutter.--Bertrams' Single-sheet Cutter.--Packing the
  Finished Paper.--Sizes of Paper.


To impart a higher gloss, or, as it is technically termed "glaze,"
to paper after it leaves the machine, it has to be subjected to
further calendering, which is accomplished either in the web, or in
sheets, according to the quality of the paper.


[Illustration: Fig. 37.]

=Web-Glazing.=--_Glazing Calender._--When paper has to be glazed
in the web, it is passed between a series of rolls, which are
constructed upon several different systems. In one form of this
machine the rolls are alternately of finely polished iron, and
compressed paper, or cotton, the iron rolls being bored hollow to
admit of their being connected to steam pipes, for heating them
when necessary. In this machine there are eight rolls, the centre
pair being both paper rolls, which have an effect equivalent to
reversing the paper, by which both sides are made alike. Another
form of glazing calender, of American origin, but which has
been improved upon by our own engineers, consists of a stack of
rolls made from chilled iron, the surfaces of which are ground
and finished with exquisite precision upon a system adopted in
America. A representation of this calender as manufactured by
Messrs. Bentley and Jackson is given in Fig. 37. Such rolls as
require heating are bored through, and their ends fitted with
brass junctions and cocks, to regulate the admission of steam.
The standards are of cast iron, planed and fitted with phosphor
bronze bearings; the bearings to carry the top roll of the stack
are furnished with wrought-iron screws and hand wheels, and
wrought-iron lifting links can be attached to raise one or more of
the rolls, according to the finish required on the paper. Compound
levers are also supplied, to regulate and adjust the pressure on
the ends of the rolls.

[Illustration: Fig. 38.]

_Damping Rolls._--An important improvement in connection with
the calendering of paper was introduced by Messrs. G. and W.
Bertram a few years since, by which a higher finish is given to
the paper than had previously been attainable. This consists
of a damping apparatus A (Fig. 38) which is placed between the
last drying cylinders B of the machine and the glazing calenders
C. The damping-rolls consist of two brass or copper rolls,
about 14 inches in diameter, through which a constant stream of
cold water is passed, while a line of steam jets, issued from
finely-perforated pipes, plays over the face of the rolls. The cold
water within the rolls condenses the steam, thereby imparting a
uniform moisture to the under surface of the paper, which enables
it to take a better surface when passing through the glazing
rolls. The steam-pipes can be regulated so as to give any amount
of dampness required by adjusting the steam cocks accordingly.
By reference to the engraving, it will be observed from the
disposition of the rolls that the web of paper is reversed, thus
equalising the moisture on both sides, by which the paper-maker is
enabled to produce an evenly-finished paper.

[Illustration: Fig. 39.]

The chilled-iron glazing-rolls, as originally introduced, were
fitted up in stacks of seven, and sometimes as many as nine rolls,
but it was found in practice that so large a number of rolls gave
unsatisfactory results; the heavy pressure, acting on the paper
immediately after leaving the drying cylinders, had the effect of
"crushing" the paper, giving it a thin feel. It is now considered
preferable to use calenders having not more than four, or at most
five rolls. An arrangement of this description, manufactured
by Bertrams, is represented in Fig. 39. The system recommended
by Mr. Dunbar is to employ three sets of rolls, disposed as
follows:--"First, a set of three rolls; second, a set to consist
of four rolls, and a stack of five to give the finishing or dry
surface. With this arrangement of calenders, and the assistance
of the damping apparatus, any desired surface can be got by
varying and regulating the drying of the paper, which any careful
machine-man can do with ordinary attention."


=Finishing.=--To give a still higher finish to the paper, it is
subjected to what is termed "friction-glazing," which consists in
passing it through a stack of rolls, formed alternately of small
iron rolls and larger paper ones, the iron rolls revolving at a
much higher speed than the paper-rolls. The effect of this final
glazing operation gives the paper a very fine surface.


=Plate-Glazing.=--_Donkin's Glazing Press._--This term, which
is also called "super-calendering," is applied to a method of
glazing hand-made paper, and is also adopted for the better
qualities of machine-made paper. It consists in placing sheets of
paper between highly polished plates of either copper or zinc,
the latter being more generally used. The metal plates, with the
sheets of paper placed alternately between them, are made up into
packs or "handfuls" (the operation being usually performed by
women), and these are passed between two powerful rolls, giving a
pressure of from twenty to thirty tons, and each pack, consisting
of about forty plates and as many sheets, is passed through the
rolls several times, the pressure being regulated by means of
screws or levers and weights acting on the ends of the top roll.
A machine for glazing paper in packs, manufactured by Messrs.
Bryan Donkin and Co., is shown in Fig. 40. Some descriptions of
paper, as "antique" and "old style," for example, are surfaced with
good cardboard instead of copper or zinc plates. As soon as the
handful has passed through the rollers, the motion of the machine
is reversed, by which means the pack is made to pass forwards
and backwards repeatedly, according to the extent of gloss or
smoothness required.


[Illustration: Fig. 40.]

=Mr. Wyatt on American Super-calendering.=--Mr. Wyatt, on a
recent visit to America, had many opportunities of witnessing the
systems of manufacture adopted there, and subsequently delivered an
interesting address to the members of the Paper-Makers' Club,[27]
in which he acknowledged the superiority of the high-class printing
papers for book-work, which has so often been the subject of
recognition in this country. Indeed, if we compare the surface of
the paper used even for ordinary technical journals in America
and that generally adopted for our own periodicals of a similar
class, we are constrained to admit that the difference is in
favour of our transatlantic competitors. "In the manufacture of
high-class super-calendered printing papers," Mr. Wyatt observes,
"for fine book-work, or as they call them book papers, the
Americans certainly excel. Whether this be due to the kind of raw
material used, to the almost universal use of the refining-engine,
which renders the pulp very soft and mellow, or to the state of
perfection to which they have brought the art of super-calendering,
or perhaps due to all three, I could not exactly determine. The
material generally used for this class of paper is poplar chemical
fibre and waste paper to the extent of 50 per cent., and even up to
75 and 80 per cent. of the total fibre, the balance being rags, or,
in cheaper qualities, sulphite wood pulp; the stuff is all mixed
together in large beaters, holding from 800 lbs. up to 1,500 lbs.
of pulp, where it is about half beaten, and then finished in one or
other form of refining-engine.

"The Americans have, I think, more thoroughly studied the question
of super-calendering paper than we, and in this respect get better
results and better work. The paper is mostly slit and trimmed
on the paper-machine, and reeled up in from two to four widths
by an ingenious contrivance called the _Manning-winder_, which
automatically keeps the tension constant on each of the reels,
whatever the diameter, and is super-calendered in narrow widths on
small calenders. These calenders are from 36 inches to 42 inches
wide, and consist of a stack of 9 to 11 rolls, alternately chilled
iron, and cotton or paper; the paper is passed through the rolls
two or three times, never less than twice, under great pressure
applied by hand-screws. The power required is very high, being
from 40 to 50 h.p. for each calender, and the speed from 450 feet
up to 600 feet per minute. The paper is not usually damped before
calendering, but is left rather under-dried from the machine;
neither is steam heat used in the rolls, which get very warm,
owing to the high speed at which they run. The rolls are driven
entirely by straps, the arrangements for the fast and slow speed
and for reeling on and off the paper being well designed and
worked out; the main strap, running at high speed, runs on a loose
pulley on the shaft of the bottom roll, by means of a powerful
friction clutch; this pulley can be made a tight one. On this
same bottom shaft is keyed a multiple V-shaped grooved friction
pulley. Another, and independent shaft, driven from the main shaft
by a crossed belt, has a small grooved pulley keyed on it, which
can be thrown in and out of gear with the large grooved pulley.
Strap-driving is thus secured throughout, and the speed can be
increased gradually without jerks, from the starting up to the
fastest speed by working the levers, gearing the friction clutch
and pulleys slowly."

In reference to the high finish of American papers, we are disposed
to attribute this mainly to the nature of the chief raw material
used--wood fibre. In the year 1854, when specimens of Mr. Charles
Watt's wood-fibre paper were first printed upon, the remarkable
gloss of the wood paper attracted much attention, and it was
noticed that the impression of the ink appeared to be well _on the
surface of the paper_, and not, as was often the case with ordinary
printing papers of the time, partially absorbed by the paper
itself. Mr. Wyatt states that poplar chemical fibre and waste paper
to the extent of 50 per cent., and even up to 75 and 80 per cent.,
are used, the balance being rags; now since the waste paper in all
probability would be composed largely of wood fibre, and as, in the
cheaper qualities, sulphite wood pulp is used in lieu of rags, it
will be fair to assume that the chief basis of the highly-finished
papers for which the Americans are justly famous is wood fibre, and
we believe that there is no other variety of cellulose which is so
susceptible of producing a naturally glossy paper as that which is
obtained from wood by the soda process.


=Mr. Arnot on Finishing.=--Mr. Arnot makes the following
observations respecting the finishing of paper:--"The paper may
be slit into widths, suitable for wet calenders, or may be cut up
into sheets, and glazed by the plate or board calenders. The former
method of surfacing or finishing has come extensively into use
in recent times, the labour involved being much less than in the
older method of finishing in sheets. Still, however, the plate
calenders are kept at work upon the higher classes of goods, it
being possible to give almost any degree of surface to good paper
by that means. There is little doubt, too, that the paper glazed by
the plate rolls retains its original softness to a greater degree
than that passed through web calenders. In the latter it is exposed
in one thickness to great pressure, and is thinned in consequence;
whereas, when the sheets are made up into piles, along with copper
or zinc plates, there is a certain amount of spring or elasticity
in the treatment which largely counteracts the crushing action of
the rolls. The web calenders consist of a series of rollers erected
in a vertical frame, and between these the paper winds, beginning
at the top and coming downwards, so that the pressure gradually
increases as the paper moves on its journey. It will be observed
that the under rolls have to bear the weight of the upper ones,
and that consequently the pressure on the paper will be greater
the lower down it descends. Many of the rollers themselves are now
made of paper, and as these possess a slight degree of elasticity,
and take a high polish, they are alternated with iron rollers
with good effect. The paper-rolls are made by sliding an immense
number of circular sheets, perforated in the centre, on to an iron
core or shaft, pressing these close together by hydraulic action,
and trimming them off on the lathe. The plate or broad calenders
consist only of two rollers, the upper one heavily weighted,
preferably by compound levers. Between these rollers the sheets
of paper, alternated with plates of copper or zinc, and made up
into bundles about an inch in thickness, are passed backwards and
forwards, the reciprocating action being produced by the movement
of a lever in the hand of an attendant. The metal and paper sheets
of different bundles may be interchanged, and the process repeated
with the effect of increasing the beauty and equality of the
finish."


[Illustration: Fig. 41.]

=Cutting.=--_Revolving Knife._--When paper is to be used in a
continuous printing-machine, or, as is often the case, has to
be exported in the web, it is supplied in rolls; otherwise it
is cut into sheets before leaving the mill. The form of cutter
generally used is what is termed the _revolving knife-cutter_, an
illustration of which, as manufactured by Bertrams, Limited, is
shown in Fig. 41. At A is shown a series of webs, the paper from
which is drawn forward by the rolls, B, and is then slit into
suitable widths, and the margin at the same time pared by circular
knives, one of which is shown at C. It then passes through a pair
of leading-rolls, after which it comes in contact with a knife,
D, attached to a revolving drum, E, pressing against a dead knife
not shown in the engraving. The sheets, as they are thus cut, drop
upon a travelling felt or apron, F, from which they are lifted and
placed in piles, by boys or girls standing on each side of the
felt. These machines will cut eight webs at one time.

[Illustration: Fig. 42.]

_Bertrams' Single-sheet Cutter._--In cases where it is necessary
that the sheets should be cut with great uniformity, as in the
case of paper bearing a water-mark, in which it is requisite that
the design should appear exactly in the centre of the sheet,
the ordinary cutter is not found to be sufficiently reliable; a
machine termed a "single-sheet cutter" is therefore used for this
purpose, of which an illustration is shown in Fig. 42. The paper
is led direct from the paper-machine, or from a reel frame, to the
drawing-in rolls, A; after which it passes through the circular
slitting-knives, B; from here it is led by the roller C to a large
wood-covered drum, D, and at the front of this drum the sheets are
cut by the cross-cutting knives, E. There are two cast-iron tapered
cones, with belt guide for adjusting the speed; a fly-wheel to
promote steadiness in working; a series of wrought-iron levers,
cranks, eccentrics, shafts, etc., for accurately regulating the
travel of paper and the cut of the horizontal knives; a small
pasting table is also fitted across the machine for mending broken
sheets.


=Packing the Finished Paper.=--The paper, after it leaves the
cutting-machine, is conveyed to the _finishing-house_, where it
is carefully examined by women, who cast aside all defective or
damaged sheets, which, under the trade names of "imperfections"
or "retree," are sometimes disposed of, at a lower rate, to the
customer for whom the order is executed. In the warehouse these
imperfections are marked with a capital R on the wrapper, or two
crosses, thus =X X=. If the paper is broken, it is sometimes
marked B =X X=; it is not generally the custom, however, to
sell imperfections, but to return them to the beater-man, to be
re-converted into pulp. The perfect sheets are then counted, and
packed up in reams consisting of 480 to 516 sheets.


=Sizes of Paper.=--The various sizes of paper are known in the
stationery trade under different designations, as demy, crown,
double crown, royal, imperial, etc. As paper is generally purchased
according to weight, the various weights per ream are also
distinguished with the size of the paper, as 16 lb. demy, 22 lb.
double crown, and so on. The following table shows the sizes of
some of the writing and printing papers in common use:--

  +----------------------+----------------+-----------------+
  |     Name.            |    Writing     |    Printing     |
  |                      |    Papers.     |     Papers.     |
  +----------------------+----------------+-----------------+
  |                      |     Inches.    |     Inches.     |
  | Foolscap             |    17  × 13¼   |    17  × 13¼    |
  | Small post (or post) |    18¾ × 15¼   |    18¾ × 15¼    |
  | Crown                |                |    20  × 15     |
  | Double crown         |                |    30  × 20     |
  | Demy                 |                |    22½ × 17¾    |
  | Royal                |                |    25  × 20     |
  | Imperial             |                |    30  × 22     |
  | Double demy          |                |    35½ × 22½    |
  | Double royal         |                |    40  × 25     |
  +----------------------+----------------+-----------------+



CHAPTER XV.

_COLOURED PAPERS._

  Coloured Papers.--Colouring Matters used in Paper-Making.--
  American Combinations for Colouring.--Mixing Colouring Materials
  with Pulp.--Colouring Paper for Artificial Flowers.--Stains for
  Glazed Papers.--Stains for Morocco Papers.--Stains for Satin
  Papers.


=Coloured Papers.=--There are several methods by which any desired
shade of colour may be imparted to paper, which are as follows:--

1. By blending with the pulp in the beating-engine some insoluble
substance, such as smalts blue--a kind of glass coloured by oxide
of cobalt--ultramarine, yellow ochre, etc.

2. By adding a coloured liquid, which simply dyes or stains the
fibre.

3. By using rags which are already coloured, in proportions to
give the required shade, in which case of course the process of
bleaching must be omitted.

4. By employing two substances, as yellow prussiate of potash
(ferrocyanide of potassium) and a persalt of iron, for example,
which, when combined, yield the requisite blue tint--Prussian blue.

By this latter method the buff shade given to what is termed
_toned paper_ is effected, by using a solution of copperas
(sulphate of iron) and an alkaline solution, or by using a solution
of pernitrate of iron. In experimenting in this direction we
have found that a mixture of solutions of sulphate of iron and
bichromate of potassa produce an agreeable and permanent buff tint.
The solutions may be added to the pulp alternately, or may be first
mixed and then at once put into the beater. From 2 to 3 ozs. of
each salt for each gallon of water may be used if the solutions are
to be mixed before using; but when applied separately the solutions
may be used in a more concentrated condition.


=Colouring Matters used in Paper-Making.=--The following
substances, used either alone or mixed in suitable proportions, are
employed in colouring pulp for paper-making:--

  Smalts blue.

  Prussian blue.

  Indigo blue.

  Aniline blues.

  Aniline reds, including eosine.

  Cochineal, for pink, etc.

  Brazil wood, which imparts either a fine red or orange-brown
  colour, according to the treatment it has undergone.

  Logwood, for violet colours.

  Chrome yellow and orange chrome.

  Orange mineral.

  Copperas, for mixing with other substances.

  Venetian red.

  Yellow ochre.

  Quercitron, or oak-bark.

  Nutgalls.

  Lamp black.

_Blue._--The coarser kind of paper used for packing is prepared
from rags blued with indigo, which, when reduced to pulp, are
not subjected to the process of bleaching. The finer kinds of
paper are blued in various ways, but the chief material used is
what is known as artificial ultramarine, of which there are many
qualities in the market, to which reference is made in another
chapter. Prussian blue is also used, but this is usually produced
directly in the beating-engine by adding in solution, 95 parts
of sulphate of iron and 100 parts of ferrocyanide of potassium
(yellow prussiate of potash). Smalts blue, which was formerly much
used before the introduction of artificial ultramarine, is still
preferred for high-classed papers as the colour is more permanent.
To obtain smalts in an exceedingly fine state of division the best
plan is to grind the colour in a little water, and then to separate
the finest particle by the process of _elutriation_, that is, by
diffusing the reduced mass through a large volume of water, and
after allowing the larger particles to subside, pouring off the
liquor in which the finer particles are suspended, to a separate
vessel, in which they are allowed to subside. If this operation is
carefully conducted the smalts may be obtained in an exceedingly
fine state of division, and we have found that in this state the
colour blends well with the pulp, and has little or no disposition
to sink through it, but produces a uniform colouring throughout.


=American Combinations for Colouring.=--Hofmann gives the following
examples of the combination of colours which have been adopted by
American manufacturers:--

_Yellow Gold Envelope_ of fine quality is made of--

  Bichromate of potash      10 lbs.
  Nitrate of lead           18  "
  Orange mineral            56  "
  Porous alum               30  "

each substance being separately dissolved and added to 400 lbs. of
pulp.

_Orange-red Gold Envelope_:--

  Bichromate of potash       7 lbs.
  Nitrate of lead           10½ "
  Orange mineral            60  "
  Porous alum               20  "

These substances are dissolved separately and added to 400 lbs. of
pulp.

_Buff Envelope_ of fine deep shade is made from--

  Bichromate of potash       3 lbs.
  Nitrate of lead            5  "
  Orange mineral            10  "
  American ochre            20  "
  Porous alum               30  "

Some half-stuff of red jute bagging. For 400 lbs. of pulp.

_Tea-Colour_ is made from a decoction of quercitron bark, the
liquid being poured into the engine, and 2 lbs. of copperas in
solution are added for every gallon of the bark extract. A little
ultramarine may be used to brighten the colour.

_Drab._--Venetian red, well washed, added to a pulp of tea-colour
made as above will give a fine drab.

_Brown_ is composed of several colours, or a very fine dark green
tea-colour brown, containing tea, buff, drab, and ink-grey, may be
made of--

  Quercitron bark liquid    15  gals.
  Bicarbonate of soda        2  lbs.
  Venetian red               4   "
  Extract of nutgalls        2½  "
  Copperas                  18   "
  Porous alum               30   "

The above proportions are for 400 lbs. of pulp.

The large proportion of alum prescribed in all the above examples
serves as a mordant, and also, with the addition of resin soap, for
sizing. All the above mixtures should be passed through a No. 60
wire-cloth into the beating-engine.


=Mixing Colouring Materials with Pulp.=--It will be readily
understood that when paper is sized in the pulp, as Mr. Hofmann
points out, the resinous alumina surrounds the fibres and prevents
the colouring materials from penetrating them. In such cases the
colouring materials are only loosely held, and a portion must
therefore be lost in the machine. If added to the pulp before it is
sized they become thoroughly mixed with the fibres, and with them
enveloped by the size. The pulp should always be coloured before it
is sized, except in cases where the alum or resin soap would injure
the colours, or be injured by them. While the pulp is being sized
and coloured, the finishing touch is given by the engine-man, who
examines it and empties it into the stuff-chest.


=Colouring Paper for Artificial Flowers.=--Davis gives the
following recipes for colouring one ream of paper of medium weight
and size, sap colours only being used, and principally those
containing much colouring matter. The gum arabic given in the
recipes is dissolved in the sap-liquor.

_Blue_ (dark) 1.--Mix 1 gallon of tincture of Berlin blue with
2 ozs. each of wax soap and gum tragacanth. 2. Mix ¾ gallon of
tincture of Berlin blue with 2 ozs. of wax soap, and 4¼ ozs. of gum
tragacanth.

_Crimson._--Mix 1 gallon of liquor of Brazil wood compounded with
borax, 2 ozs. wax soap and 8¾ ozs. of gum arabic.

_Green._--1. Take ½ gallon of liquor of sap-green[28], 4¼ ozs.
of indigo rubbed up fine, 1 oz. of wax soap, and 4½ ozs. of gum
arabic. 2. ½ gallon of sap-green liquor, 4¼ ozs. of distilled
verdigris, 1 oz. of wax soap, and 4½ ozs. of gum arabic.

_Yellow_ (golden).--Mix 6½ ozs. of gamboge with 2 ozs. of wax soap.

_Yellow_ (lemon).--1. Compound 1 gallon of juice of Persian berries
with 2 ozs. of wax soap and 8¾ ozs. of gum arabic. 2. Add to 1
gallon of quercitron liquor, compounded with solution of tin, 2
ozs. of wax soap, and 8¾ ozs. of gum arabic.

_Yellow_ (pale).--Mix 1 gallon of fustic, 2 ozs. of wax soap, and
8¾ ozs. gum arabic.

_Yellow_ (green).--Compound 1 gallon of sap-green liquor with 2
ozs. each of distilled verdigris and wax soap, and 8¾ ozs. of gum
arabic.

_Red_ (dark).--1 gallon of Brazil-wood liquor, 2 ozs. of wax soap,
and 8¾ ozs. of gum arabic.

_Rose Colour._--Mix 1 gallon of cochineal liquor with 2 ozs. of wax
soap, and 8¾ ozs. of gum arabic.

_Scarlet._--1. Mix 1 gallon of Brazil wood liquor compounded with
alum and a solution of copper, with 2 ozs. of wax soap, and 8¾ ozs.
of gum arabic. 2. Mix 1 gallon of cochineal liquor compounded with
citrate of tin, with 2 ozs. of wax soap, and 8¾ ozs. of gum arabic.


=Stains for Glazed Papers.=--Owing to the cheapness of these
papers glue is used in lieu of the more expensive gums; 1 lb. of
glue dissolved in 1¼ gallon of water; the proportions of colouring
materials are given for 1 ream of paper of medium weight and size.

_Black._--1. Dissolve 1 lb. of glue in 1¼ gallon of water;
triturate this with lampblack (1 lb.) previously rubbed up in rye
whiskey; Frankfort black, 2¾ lbs.; Paris blue, 2 ozs.; wax soap, 1
oz.; then add liquor of logwood, 1½ lb. 2. 1½ gallon of liquor of
logwood compounded with sulphate of iron, 1 oz. of wax soap, and 4½
ozs. of gum arabic.

_Blue_ (azure).--1¼ gallon of glue liquor, as before, mixed with 1½
lb. Berlin blue, 2¾ lbs. powdered chalk, 2¼ ozs. of light mineral
blue, and 2 ozs. of wax soap.

_Blue_ (dark).--Mix with 1¼ gallon of glue liquor, 4½ lbs. of
powdered chalk, 4¼ ozs. of Paris blue, and 2 ozs. of wax soap.

_Blue_ (pale).--1. Mix ½ gallon of tincture of Berlin blue and 1
oz. of wax soap with 3½ ozs. of solution of gum tragacanth. 2. Take
1¼ gallon of glue liquor and mix with 4 lbs. of powdered chalk and
2 ozs. each of Paris blue and wax soap.

_Brown_ (dark).--1. 1¼ gallon of glue liquor, mixed with 6 lbs.
each of colcothar (jewellers' rouge) and English pink, 1½ lb. of
powdered chalk, and 2 ozs. of wax soap. 2. Dissolve 1 oz. of wax
soap and 4½ ozs. of gum arabic in ½ gallon of good Brazil-wood
liquor, and add a like quantity of tincture of gallnuts.

_Green_ (copper).--Mix in 1¼ gallon of glue liquor 4 lbs. of
English verdigris, 1½ lb. of powdered chalk, and 4 ozs. of wax soap.

_Green_ (pale).--Mix with 1¼ gallon of glue liquor 1 lb. of Bremen
blue, 8½ ozs. of whiting, 1 oz. of pale chrome yellow, and 2 ozs.
of wax soap.

_Lemon Colour._--Mix in 1¼ gallon of glue liquor 13 ozs. of lemon
chrome, 2 lbs. of powdered chalk, and 2 ozs. of wax soap.

_Orange-Yellow._--Mix in 1¼ gallon of glue liquor 2 lbs. of lemon
chrome, 1 lb. of Turkish minium, 2 lbs. of white lead, and 2 ozs.
of wax soap.

_Red_ (cherry).--Mix in 1¼ gallon of glue liquor 8½ lbs. of Turkey
red, previously mixed up with ¼ gallon of Brazil-wood liquor, and 2
ozs. of wax soap.

_Red_ (dark).--Mix ¾ gallon of Brazil-wood liquor with wax soap 1
oz., and gum arabic 4½ ozs.

_Red_ (pale).--To 1¼ gallon of glue liquor is to be added 8¼ lbs.
of Turkey red previously rubbed up with 2 ozs. of wax soap.

_Violet._--4½ ozs. of gum arabic, and 1 oz. of wax soap are to
be mixed with ½ gallon of good logwood liquor. When the gum is
dissolved, mix with it enough potash to form a mordant.


=Stains for Morocco Papers.=--For 1 ream of paper of medium size
and weight the following recipes are recommended:--

_Black._--8¾ ozs. of good parchment shavings are dissolved in 1½
gallon of water; into this liquid is to be stirred lampblack, 1
lb., Frankfort black, 3 lbs., and Paris blue, 1¾ oz.

_Blue_ (dark).--Dissolve parchment shavings, as before, and mix in
8¼ lbs. of white lead and 4½ lbs. of Paris blue.

_Blue_ (light).--Dissolve parchment shavings, as before, and mix in
8¾ lbs. of white lead and 2¼ ozs. of Paris blue.

_Green_ (dark).--Dissolve 13 ozs. of parchment shavings in 2½
gallons of water, and mix in 10 lbs. of Schweinfurth green.

_Green_ (pale).--Prepare solution of parchment as in the last, and
mix with 8¾ lbs. of Schweinfurth green and 1 lb. of fine Paris blue.

_Orange-Yellow._--8¾ ozs. of parchment shavings are to be dissolved
in 1½ gallon of water, and then mixed with 1½ lb. of lemon chrome,
8¾ ozs. of orange chrome, and 1 lb. of white lead.

_Red_ (dark).--To the same quantity of parchment liquor as the last
is to be added 7¾ lbs. of fine cinnabar, and 1 lb. of Turkey red.

_Red_ (pale).--To the same quantity of parchment liquor add 8¾ ozs.
of Turkey red.

_Violet_ (light).--To 1½ gallon of parchment liquor add 4¼ lbs. of
white lead, 13 ozs. of light mineral blue, and 8¾ ozs. of scarlet
lake.

_Violet_ (dark).--To 1½ gallon of parchment liquor add 3¾ lbs. of
white lead, 1 lb. of pale mineral blue, and 8¾ ozs. of scarlet lake.

_Yellow_ (pale).--To 1½ gallon of parchment liquor add 2 lbs. of
light chrome yellow and 8¾ ozs. of white lead.


=Stains for Satin Papers.=--For each ream of paper of medium weight
and size the following recipes are given:--

_Blue_ (azure).--13 ozs. of parchment are dissolved in 2½ gallons
of water and mixed with 3 lbs. of Bremen blue, 1¾ lb. of English
mineral blue, and 4½ ozs. of wax soap.

_Blue_ (light).--8¾ ozs. of parchment are to be dissolved in 1½
gallon of water, and to be mixed with light chrome yellow, 13 ozs.;
colcothar, 6½ ozs.; Frankfort black, 2 ozs.; powdered chalk 3 lbs.,
and wax soap, 3½ ozs.

_Brown_ (reddish).--1½ gallon of parchment liquor as the last, to
which is added yellow ochre, 1 lb.; light chrome yellow, 4½ ozs.;
white lead, 1 lb.; red ochre, 1 oz., and wax soap, 3½ ozs.

_Brown_ (light).--1½ gallon of parchment liquor, as before,
to which is added 13 ozs. of light chrome yellow, 6½ ozs. of
colcothar, 2 ozs. of Frankfort black, 3 lbs. of powdered chalk, and
3½ ozs. of wax soap.

_Grey_ (light).--1½ gallon of parchment liquor is mixed with 4¼
lbs. of powdered chalk, 8¾ ozs. of Frankfort black, 1 oz. of Paris
blue, and 3½ ozs. of wax soap.

_Grey_ (bluish).--To the above quantity of parchment liquor add 4¼
lbs. of powdered chalk, 1 lb. of light mineral blue, 4¼ ozs. of
English green, 1¾ oz. of Frankfort black, and 3½ ozs. of wax soap.

_Green_ (brownish).--To the same quantity of parchment liquor add
Schweinfurth green, 1 lb.; mineral green, 8¾ ozs.; burnt umber and
English pink, of each 4¼ ozs.; whiting, 1 lb., and wax soap, 3½ ozs.

_Green_ (light).--To the same quantity of parchment liquor add
English green and powdered chalk, of each 2¾ lbs., and 3½ ozs. of
wax soap.

_Lemon Colour._--To the same quantity of parchment liquor add lemon
chrome, 1½ lb.; white lead 1 lb., and wax soap, 3½ ozs.

_Orange-Yellow._--Parchment liquor as before, 1½ gallon, to which
is added lemon chrome, 4¼ lbs.; Turkey red, 8¾ ozs.; white lead, 1
lb., and wax soap, 3½ ozs.

_Rose Colour._--1½ gallon of parchment liquor as before, to which
is added ¾ gallon of rose colour prepared from Brazil wood and
chalk, and 6½ lbs. of wax soap.

_Violet_ (light).--1½ gallon of parchment liquor as above, mixed
with light mineral blue and scarlet lake, of each 1½ lb.; white
lead, 1 lb., and wax soap, 3½ ozs.

_White._--To 1½ gallons of parchment liquor is added fine Kremnitz
white, 8¾ lbs., Bremen blue, 4¼ ozs., and wax soap, 3½ ozs.

_Silver White._--1½ gallon of parchment liquor mixed with Kremnitz
white, 8¾ lbs., Frankfort black, 8¾ ozs., and wax soap, 3½ ozs.

_Pale Yellow._--1½ gallon of parchment liquor, to which is added 4½
lbs. of light chrome yellow, 1 lb. of powdered chalk, and 3½ ozs.
of wax soap.



CHAPTER XVI.

_MISCELLANEOUS PAPERS._

  Waterproof Paper.--Scoffern and Tidcombe's process.--Dr. Wright's
  process for preparing Cupro-Ammonium.--Jouglet's process.--
  Waterproof Composition for Paper.--Toughening Paper.--Morfit's
  process.--Transparent Paper.--Tracing Paper.--Varnished Paper.--
  Oiled Paper.--Lithographic Paper.--Cork Paper.--New Japanese
  Paper.--Blotting Paper.--Parchment Paper.--Test Papers.


=Waterproof Paper.=--_Scoffern and Tidcombe's Process._--In this
process, for which a patent was granted in 1875, the well-known
solubility of cellulose in cupro-ammonium is taken advantage of,
for the purpose of producing waterproof paper by destroying its
absorptive properties. After the paper is made and dried in the
usual way by the paper-making machine, it is led through a bath of
cupro-ammonium, having a roll or rollers therein, or in connection
therewith, either on reels on which the paper is reeled, or from
the continuous web of paper itself directly from the machine,
and from this bath it is led over a table of wire-cloth, or
india-rubber, or over a series of rollers forming a table, under
which steam-pipes are placed for the purpose of "setting," or
partially drying, the web; it is then led over suitable reels in
a hot-air chamber to season or finish the treated paper, which is
then cut as the paper runs, by the ordinary cutting machine, into
the required sheets. The chamber in which the paper is treated
is ventilated as follows:--Over the bath and hot-air chamber is
another chamber having openings leading into the hot-air chamber,
and at these openings a steam-blast, or fan-blast, is applied,
which ventilates the chamber in which the paper is heated,
and drives the ammonia into contact with either sulphurous or
hydrochloric acid, and by this means the ammonia is recovered in a
solid form which would otherwise be wasted.

The inventors also incorporate hydrated oxide of copper with
paper pulp, so that after it is made into paper it has only to be
subjected to the action of ammonia, as ordinarily done, or to the
action of gaseous ammonia mingled with steam. Brown papers are
strengthened and glazed by passing them through a bath of pulp
containing cupro-ammonium, either with or without pitch, tar, or
other resinous matters. It is well known that by passing paper
through a cupro-ammonium bath it is surface dissolved and glazed
by its own material, and if it be desired to unite two or more
sheets together this is the most economical way of conducting the
operation; but if it be desired to strengthen and glaze a single
thickness of paper or millboard, it is considered undesirable to
make the glaze by dissolving a portion of the paper itself. In
this case the inventors pass the web or sheet of paper through a
bath, not of cupro-ammonium simply, but of cupro-ammonium in which
ligneous material is already dissolved; and when the glazing of
brown paper is to be effected, they prefer to fortify the bath
with tar, pitch, marine glue, or other resinous materials. By this
process, panels and tiles may be manufactured from millboard,
or thick sheets of ligneous material made from pulp already
incorporated with hydrated oxide of copper. The panels, etc., are
passed, by means of an endless web, through a bath of ammoniacal
solution, or the vapour of ammonia and steam, and the tiles or
panels may be surface-glazed by exposing them while moist to the
action of fluo-silicic acid gas, by which silica is deposited in
the material and on its surface.


=Dr. Wright's Process for preparing Cupro-ammonium.=--This process,
which has been adopted at the Willesden Paper Mills, may be thus
briefly described:--In the first part of the process, metallic
copper, in small lumps, solid metal, or clippings, etc., is covered
with a solution of ammonia in water, or with a weak solution
of cupro-ammonium hydrate, containing an amount of free ammonia
in solution dependent upon the strength of the copper solution
ultimately required; a current of air is then caused to pass
through the whole by means of an air-pump, in such a manner that
the bubbles of air pass over and amongst the fragments of metallic
copper, which, if in small particles, may be advantageously kept in
suspension by any convenient agitator. In a few hours the liquid
becomes saturated with as much copper as it can dissolve, the
rate of solution varying with the form of the vessel containing
the materials, the strength of the ammoniacal fluid, and the rate
of the passage of the stream of air. To carry this process into
effect, metallic copper in fragments of convenient size is loosely
piled inside a vertical tube or tower, and water is allowed to
trickle from a pipe over the copper so as to keep its surface
moist. At the base of the tower a current of air, mixed with
ammonia gas, is caused to pass into the tower, so as to ascend
upwards, meeting the descending water as it trickles over the
copper. Under these conditions the copper becomes oxidised, and the
water dissolves firstly the ammonia gas, and, secondly, the oxide
of copper formed, so that the liquor which passes out at the base
of the tower is a solution of cupro-ammonium hydrate, the strength
of which depends on the proportions subsisting between the bulk
of the mass of copper, the quantity of water trickling over it,
and the amount of air and ammonia gas supplied in a given time.
As an example of the method of carrying out the above process,
the inventor proceeds as follows:--He constructs a vertical iron
tower which may be ten inches in internal diameter and ten feet
in height, and this is filled with scraps of sheet copper. On
this water is allowed to trickle, whilst at the base of the tower
a mixture of air and gaseous ammonia is allowed to pass upwards
through the tower, by which a solution of cupro-ammonium is formed,
which is allowed to trickle out at the base of the tower into a
tank. It has been found advantageous to use a series of towers,
allowing the air and ammonia gas that pass out at the top of the
first tower to enter at the bottom of the second tower, and so on
successively throughout the series. The weaker solutions produced
in the later towers of the series are used instead of water in the
earlier towers, so that practically all the ammonia gas originally
used is obtained in the form of cupro-ammonium hydrate solution,
issuing from the first tower of the series.

The cupro-ammonium process, as carried on at the Willesden
Mills, is applied to ropes, netting, etc., by immersing them in
a solution of cupro-ammonium, which, when they are subsequently
dried, gives them a varnished appearance, while at the same time,
the fibres having become cemented together by the action of the
cupro-ammonium, their strength is increased. By the same process
paper, canvas, and other manufactured articles are rendered
waterproof. A concentrated solution of cupro-ammonium may also be
used for securing envelopes, whereby the adhesion of the surfaces
of the paper is rendered perfect, and the only means of opening the
envelope is by cutting or tearing the paper.


=Jouglet's Process.=--This process, which with modifications has
been adopted by others, is based on the solvent action on cellulose
of a solution of oxide of copper in ammonia. A quantity of this
solution is placed in a tank, and the paper rapidly passed over and
in contact with the surface of the liquid, by means of suitable
rollers in motion. The paper is afterwards pressed between a pair
of rolls and dried by the ordinary drying cylinders. The brief
contact of the paper with the liquid occasions just sufficient
action on the cellulose to have the effect of an impermeable
varnish.


=Waterproof Composition for Paper.=--The following composition for
rendering paper waterproof for roofing and flooring purposes has
been patented in America.[29] By preference good, hard manilla
paper is selected, and a composition of the following ingredients
is applied with a brush, or by means of rollers:--Glue, 2 lbs., is
dissolved in 3 gallons of crude petroleum, of about the density of
33° B. at 60° F.; 35 gallons of resin oil, and about half a pint
of oil of eucalyptus, which will have the effect of destroying the
objectionable odour of the resin oil. To this mixture is further
added about 4 gallons of any ordinary drier. The above ingredients
are to be thoroughly mixed by agitation, and the composition
brushed over the paper in a room heated to about 80° F., and
allowed to dry. It is said that paper thus coated will exclude
wind, cold, dampness, and dust.


=Toughening Paper.=--_Morfit's Process._--The object of the
following process is to produce a paper "toughened in a degree
and quality distinctively from any other in the market," and
is applicable to all kinds of paper, but more particularly to
those made with inferior grades of pulp for printing newspapers,
and for wrapping papers. The means employed are the seaweeds
which form glutinous liquors with water, such as Carrageen, or
Irish moss, Agar-agar, and the like. Any of such seaweeds may be
employed, either separately or mixed with another of its kind,
according to the judgment of the operator and the sort of paper
to be manufactured, but some seaweeds are superior to others for
this purpose. The raw seaweed is first washed, and then boiled
with water until all the soluble matter has been extracted, and
the resulting liquor is then strained. The hot strained liquor
forms the bath in which sheets of paper or pulp are to be treated.
If desired, resin soap and aluminous cake may be added to the
glutinous liquor, but these "serve rather to size and make the
paper rustle than increase its toughness." If the paper is to be
treated in the form of sheets or web, it is to be passed, as it
leaves the wire-cloth in which it is formed, through a hot solution
of the seaweed alone, or mixed with resinous soap and aluminous
cake, and dried by means of suitable machinery. To apply it to
the pulp, the latter is to be diffused in the hot liquor, and
the sheets or web made therefrom in the usual manner. The proper
proportions of seaweed, resinous soap, and aluminous cake will
vary with the kind of pulp and sheets under treatment, and must be
adjusted as the judgment of the operator determines best for each
operation.


=Transparent Paper.=--There are several methods of rendering paper
transparent, amongst which the following has been recommended:--

  Boiled and bleached linseed oil      120 parts.
  Lead turnings                          6   "
  Oxide of zinc                         30   "
  Venice turpentine                      3   "

The above ingredients are placed in an iron or other suitable
vessel, in which they are thoroughly mixed, and the whole then
boiled for about eight hours. The mixture is then allowed to
cool, when it is again well stirred and the following substances
added:--White copal, 30 parts; gum sandarac, 2 parts, these
ingredients being well incorporated by stirring.


=Tracing Paper.=--Sheets of smooth unsized paper are laid flat on
a table, and then carefully coated on one side only with a varnish
composed of Canada balsam and oil of turpentine. The brush used
for this purpose must be a clean sash tool, and when the first
sheet has been varnished in this way it is to be hung across a line
to dry. The operation is then to be applied to fresh sheets in
succession until the required quantity of paper has been treated.
In the event of one coating of the varnish not rendering the paper
sufficiently transparent, a second coating may be applied when the
first coating has become quite dry.


=Varnished Paper.=--When it is desired to varnish the surface of
paper, card-work, pasteboard, etc., it must first be rendered
non-absorbent with two or three coatings of size, which will also
prevent the varnish from acting upon any colour or design which may
be impressed upon the paper. The size may be made by dissolving
isinglass in boiling water, or by boiling clean parchment cuttings
in water until a clear solution is formed, which, after straining,
is ready for use. If necessary, for very delicate purposes, the
size thus prepared may be clarified with a little white of egg.
The size should be applied, as in the former case, with a clean
sash tool, but the touch should be light, especially for the first
coating, lest the inks or colours should run or become bleared.
When dry, the varnish may be applied in the usual way.


=Oiled Paper.=--Sheets of paper are brushed over with boiled
linseed oil, and then hung up to dry. Paper thus prepared is
waterproof, and has been used as a substitute for bladder and
gut skins for covering jam pots, etc., but the introduction of
parchment paper has almost entirely superseded it.


=Lithographic Paper.=--This paper, which is written upon with
lithographic ink, may be prepared by either of the following
formulæ:--1. Take starch, 6 ozs.; gum arabic, 2 ozs.; alum, 1 oz.
Make a strong solution of each separately in hot water, then mix
the whole and strain the liquor through gauze. It must be applied
to one side of the paper while still warm by means of a soft brush
or sponge; a second or third coating may be given as the preceding
one becomes dry. The paper is finally pressed to render it smooth.
2. The paper must first receive three coats of thin size, one coat
of good white starch, and one coat of a weak solution of gamboge in
water. The ingredients are to be applied cold with a sponge, and
each coat allowed to dry before the next is applied.


=Cork Paper.=--A paper under this title was patented in America
by Messrs. H. Felt and Co.; it is prepared by coating one side
of a thick, soft, and flexible paper with a mixture composed of
glue, 20; gelatine, 1; and molasses, 3 parts, and covering with
finely-powdered cork, which is afterwards lightly rolled in. The
paper thus prepared is said to be used for packing bottles.


=New Japanese Paper.=--According to the _Bulletin du Musée
Commercial_, a native of Japan has recently invented a new process
by which paper may be made from seaweed. The paper thus made is
said to be very strong, almost untearable, and is sufficiently
transparent to admit of its being used as a substitute for window
glass; it takes all colours well, and in many respects resembles
old window glass.--_Board of Trade Journal._


=Blotting Paper.=--This paper, requiring to be very absorbent, is
not sized, but is prepared with starch alone, which, while holding
the fibres together, does not affect the absorbent property of the
paper. Dunbar gives a recipe for making blotting paper which has
been found successful, and from which we make a few extracts. In
selecting materials for blotting, of high-class, cotton rags of the
weakest and tenderest description procurable should be chosen. Boil
them with 4 lbs. of caustic soda to the cwt.--that is, if you have
no facilities for boiling them in lime alone. When furnished to the
breaking-engine, wash the rags thoroughly before letting down the
roll; when this is done, reduce them to half-stuff, and as soon as
possible convey them to the potcher. When up to the desired colour,
drain immediately. The breaker-plate should be sharp for blottings,
and the beater-roll and plate also in good order, and the stuff
beaten smartly for not more than an hour and a half in the engine.
For pink blottings furnish two-thirds white cottons and one-third
of Turkey reds if they can be got, or dye with cochineal to desired
shade; empty down to the machine before starting, and see that the
vacuum pumps are in good condition. Remove weights from couch-roll,
and if there are lifting screws raise the top couch-roll a little.
Take shake-belt off, as the shake will not be required. Press light
with first press, and have the top roll of the second press covered
with an ordinary jacket similar to couch-roll jacket. Dry hard, and
pass through one calender with weights off, and roll as light as
possible, just enough to smooth slightly.


=Parchment Paper.=--This paper, which is extensively used for
covering jars and pots for pickles and jams, is prepared, according
to the process of Poumarède and Figuier, as follows:--White unsized
paper is dipped for half a minute in strong sulphuric acid,
specific gravity 1·842, and afterwards in water containing a
little ammonia. By Gaine's process (1857) unsized paper is plunged
for a few seconds into sulphuric acid diluted with half to a
quarter of its bulk of water (the acid being added to the water),
and the solution allowed to cool until of the same temperature as
the air. The paper is afterwards washed with weak ammonia. This
process, which has been extensively worked by Messrs. De la Rue and
Co., produces a far better material than the foregoing.


=Mill and Card-board.=--In the manufacture of boards refuse
materials of all kinds that occur in the paper-mill may be used,
and these are sorted according to the quality of boards for which
they are best suited. After being well beaten the resulting mass is
mixed with suitable proportions of rag pulp, kaolin, chalk, white
clays, &c. There are four principal processes by which boards are
manufactured, namely,

1. By superposing several sheets of paper and causing them to unite
by a sizing material.

2. By superposing several wet leaves at the time of couching.

3. By moulds provided with thick deckles.

4. By special machines similar to those used for making continuous
webs of paper, but without a drying cylinder, the sheets being
dried in the open air or in a heated room.

The third method is only adopted for boards of moderate thickness,
as an excess of pulp would render the draining difficult.


=Making Paper or Cardboard with two Faces by Ordinary Machine.=--By
this process, recently patented by Mr. A. Diana, all kinds of thin
or thick paper or cardboard are manufactured with two different
faces by means of the ordinary paper-machine, having a single
flat table with a single wire-gauze web, without requiring a
second metallic web. For this purpose the two pulps are prepared
separately, and one is caused to pass on to the web in an almost
liquid condition; this is allowed to drain off sufficiently, and
the second pulp (also in a liquid condition) is then passed
uniformly upon the whole surface of the previous layer. The water
drains off from this layer through the first layer, and the paper
or cardboard is thus directly formed with two different faces, the
subsequent operations being as ordinarily employed in paper-making.
The space between two of the suction cases employed for drawing off
the water in the pulp is a suitable point for the distribution of
the diluted second pulp, which is almost liquid.


=Test Papers.=--These papers, which are extensively used both
in the laboratory and the factory, for determining the presence
of acids or alkalies in various liquids, may be prepared as
follows:--_Litmus paper_, for detecting the presence of acids, is
prepared by first making an infusion of litmus. Reduce to a paste
with a pestle and mortar 1 oz. of litmus, adding a little boiling
water; then add more boiling water--from 3 to 4 ozs. in all--and
put the mixture into a flask and boil for a few minutes; finally,
add more boiling water to make up half a pint, and when cold filter
the liquor. To prepare the test paper, a sufficient quantity of the
liquid being poured into a flat dish, pieces of unsized paper are
steeped in the blue liquid, so that all surfaces may be thoroughly
wetted; the paper is then to be hung up by one corner to drain, and
afterwards dried. As many sheets of paper as may be required should
be treated in this way, and the sheets afterwards cut up into
convenient strips for use. _Red litmus paper_, for detecting slight
traces of alkali in liquids, may be prepared by dipping a glass
rod, previously dipped into a very dilute solution of sulphuric
acid, into one-half of the above infusion, repeating the operation
cautiously until the liquid turns from blue to a slightly red tint.
Unsized paper when dipped in this will acquire a reddish colour
which is very sensitive to the action of weak alkaline liquors, and
the vapour of ammonia restores the blue colour instantly. _Turmeric
paper_ is prepared by dipping unsized paper in a decoction of
turmeric--about 2 ozs. to the pint. Paper steeped in this solution
and dried acquires a yellow colour, which turns brown in alkaline
solutions.



CHAPTER XVII.

_MACHINERY USED IN PAPER-MAKING._

  Bentley and Jackson's Drum Washer.--Drying Cylinder.--Self-Acting
  Dry Felt Regulator.--Paper Cutting Machine.--Single Web
  Winding Machine.--Cooling and Damping Rolls.--Reversing or
  Plate Glazing Calender.--Plate Planing Machine.--Roll Bar
  Planing Machine.--Washing Cylinder for Rag Engine.--Bleach
  Pump.--Three-roll Smoothing Presses.--Back-water Pump.--Web
  Glazing Calender.--Reeling Machine.--Web Ripping Machine.--
  Roeckner's Clarifier.--Marshall's Perfecting Engine.


Apart from the mechanical contrivances which are referred to
in various parts of this work, in which their application is
explained, it will be necessary to direct attention to certain
machines and appliances which are adopted at some of the more
advanced paper-mills in this country and in America; but since
the various makers of paper-makers' machinery are constantly
introducing improvements to meet the requirements of the
manufacturer, we must refer the reader to these firms for fuller
information than can be given in the limited scope of this
treatise. Many of the improvements in paper-making machinery
consist in modifications--sometimes of a very important nature--in
the construction of certain parts of a machine, whereby the
efficiency of the machine as a whole is in some cases considerably
augmented. Without offering any critical remarks upon the merits
of the respective improvements which have been introduced, it
will be sufficient to direct attention to the manufacturer's own
description of the principal features of the special mechanical
contrivance which he produces for the use of the paper-maker. It
may also be said that innumerable patents have been obtained for
various improvements in machinery, or parts of machines, engines,
etc., which can readily be referred to at the Library of the Patent
Office, or any of the public libraries throughout the Kingdom.


[Illustration: Fig. 43.]

=Bentley and Jackson's Drum-Washer.=--This drum-washer, for use in
the rag-engine, is shown in Fig. 43. It has cast-iron ends, strong
copper buckets, shaft, stands, lifting-gear, and driving-wheel,
but instead of the drum being covered with the ordinary strong
brass backing-wire, it is covered with their improved "honey-comb"
_backing-plates_, over which the fine wire is wrapped as usual. The
honey-comb backing consists of tough rolled brass or copper plates,
curved to suit the diameter of the drum, and secured to its ends by
cross-bars. It is practicably indestructible, strengthens the drum,
and by maintaining its cylindrical form, adds considerably to the
durability of the fine covering-wire.


[Illustration: Fig. 44.]

=Drying Cylinders.=--These cylinders, by the same firm, for which
patents were obtained in 1872 and 1887, are made with concave and
convex ends, the latter type being shown in Fig. 44. The cylinder
body is made of hard cast-iron, turned and polished on outside
surface. The ends and trunnions are of tough cast iron, turned
to fit into their places, and there secured by bolts and nuts by
a patented method, whereby no bolts (excepting for the manhole)
are put through the metal, an unbroken surface is preserved, and
the annoyance of leakage through the bolt-holes is avoided. A
manhole and cover is fitted to all cylinders 3 feet in diameter
and upwards, and a water-lifter and pipe to remove the condensed
steam. The trunnions are bored to receive nozzles or junctions
for admitting steam, and the whole, when completed, is carefully
balanced and tested by steam pressure to 35 lbs. per square inch.
The firm state that they have made cylinders from 2 to 10 feet in
diameter by this system.


[Illustration: Fig. 45.]

=Self-acting Dry Felt Regulator.=--This contrivance, which is
manufactured by Messrs. Bentley and Jackson, is represented in
front and side elevation in Fig. 45. A is the framing of the
paper-machine, B the felt-rollers, C the dry felt; D is a slide
carrying one end of the felt guide-roller B; C is a shaft across
the machine, with a pulley F, two-keyed on one end, and a bevel
pinion two-keyed on the other end. The pulley F and pinion H are
keyed together, and run loose upon the shaft G; I is a bevel-wheel,
gearing into the pinions H and 2. The wheel I is connected by
a spindle and a pair of bevel-wheels to a screw E, which works
through a threaded bush. When the machine is at work, if the felt
C should run on one side, it will pass between the pulley F and
the guide-roller B, causing the pulley to revolve, and turning the
screw E in the threaded bush, thereby moving the slide fixing D and
the guide-roller B, which causes the felt to run back. Should the
felt run to the other side, it will run in contact with the pulley
F 2, and thus reverse the motion of the guide-roller B.


[Illustration: Fig. 46.]

=Paper-cutting Machine.=--This machine (Fig. 46), which is
manufactured by the same firm, is constructed to cut from one to
eight webs simultaneously, in sheets of any required length, from
8 to 60 inches. It is built on the "Verny" principle, and its
operation is as follows:--The webs of paper from the reel-rolls
are carried by an endless felt, and the paper is drawn off the
rolls by travelling cast-iron gripper beams, which firmly grasp
the felt and the webs of paper to be cut, the travel of the beams
being equal to the length of the sheet of paper to be cut. When the
required length of the sheet is drawn from the rolls, a cast-iron
clamp, placed close to the dead cross-cut knife, descends and
firmly holds the paper until the movable cross-cut knife has cut
off the sheets, which fall on a second endless felt, and are placed
by the catchers in the usual manner. As soon as the sheets are cut,
the clamp is released, and the travelling-grippers are again ready
to seize the paper and repeat the operation.


[Illustration: Fig. 47.]

=Single Web Winding Machine.=--This machine (Fig. 47) is constructed
for preparing webs of paper for continuous printing-presses. The
roll of paper to be prepared is carried by brass bearings having
vertical and horizontal screw adjustments attached to standards
mounted on a slide, and movable by a screw transversely on the
machine to accommodate the deckle edges. The paper web is taken
through a pair of iron draw-rolls, carried by brass bearings,
fitted in cast-iron stands; there are two pairs of ripping-knives
with bosses, springs, and collars, mounted on turned wrought-iron
shafts running in brass bearings carried by cast-iron stands; a
wrought-iron leading-roll and carrying brackets fitted with brass
bushes; a copper measuring roll counter, geared to indicate up to
10,000 yards, with disengaging apparatus to cease measuring when the
paper breaks; a friction-drum 2 feet in diameter, made of wood,
mounted on cast-iron rings, and a wrought-iron shaft, all carefully
turned and balanced; two cast-iron swivelling arms, with brass
sliding bearings to carry the mandrel on which the prepared web is
to be wound, with screws, struts, wheels and shaft to regulate the
angular pressure of the roll of paper against the wood drum,
according to its weight and the quantity of paper.


[Illustration: Fig. 48.]

[Illustration: Fig. 49.]

=Cooling and Damping Rolls.=--The illustration (Fig. 48) represents
an apparatus, constructed by Messrs. Bentley and Jackson, for
cooling and damping paper after leaving the drying cylinders
and before passing through the calenders. It consists of two
brass rolls bored and fitted with cast-iron ends, brass nozzles,
and regulating taps, through which the rolls are supplied with
a constant flow of water. The rolls are carried by cast-iron
standards, fitted with brass steps and cast-iron caps. Jets of
steam are blown on each of the rolls from a perforated copper pipe
running parallel with, and at a little distance from, the body of
the roll. The steam is condensed on the cold surfaces of the brass
rolls, and absorbed by the web of paper, which passes around and in
contact with their surfaces, and is consequently damped on _both_
sides. The perforated steam-pipes are enclosed by copper hoods,
to prevent the steam from spreading, and the supply of steam is
regulated by ordinary brass valves or cocks. The rolls are geared
together by a pair of spur-wheels, and driven by a pulley of
suitable diameter.


[Illustration: Fig. 50.]

=Reversing or Plate-glazing Calender.=--This machine, which is
shown in Figs. 49 and 50, is also made by the firm referred to, and
consists of two hammered iron rolls, each about twelve inches in
diameter, of any suitable length, carefully turned and carried by
strong cast-iron standards, fitted with bell-metal steps. The top
roll is provided with setting-down blocks and brasses, compound
levers and weights to regulate the pressure required. The two rolls
are geared together by strong shrouded wheels, and driven by a
strong cast-iron spur-wheel and pinion, a driving-shaft, fast and
loose pulleys, carried by cast-iron stands and pedestals fitted
with brass steps. The machine is fitted with two metal feed-tables,
and a self-acting apparatus for returning the sheets to the rolls,
and a handle-lever, slide-bar, and strap-forks for starting and
reversing.


[Illustration: Fig. 51.]

=Plate-planing Machine.=--This machine, which is manufactured by
Messrs. Bryan Donkin and Co., of Bermondsey, is shown in Fig. 51.
By its aid the plates of rag-engines can be sharpened without being
taken to pieces. The slide of the machine is made exactly like the
roll-bar planing machine (see below), and is so arranged that it
can easily be taken off and used for sharpening roll-bars.


[Illustration: Fig. 52.]

[Illustration: Fig. 53.]

=Roll-Ear Planing Machine.=--In the accompanying engraving (Fig.
52) is shown an apparatus fitted to a rag-engine for sharpening
rag-engine roll-bars, and it will be seen that by means of it the
operation can be performed without removing the roll from its
usual position. The edges of the bars are first planed by a tool
supplied by the manufacturers to render the whole cylindrical
before sharpening them; the bevelled sides are then planed by
suitable tools, two of which accompany the apparatus. This method
of sharpening renders the bars uniform in shape, the roll is kept
in better working order, and it can be dressed in considerably less
time, and at less expense, than can be done by chipping by hand.


=Washing-Cylinder for Rag-Engine.=--The illustration at Fig. 53
represents the machine as manufactured by Messrs. Bryan Donkin and
Co. It is so made that the water is delivered on the driving side
of the rag-engine, thus avoiding any trough across the engine, and
admitting of the midfeather being thin, as is usual in cast-iron
engines. It is all self-contained, and the driving apparatus is
wholly on the outside of the engine. The raising and lowering are
effected by a worm and worm-wheel, so that the cylinder will stop
at any point required.


[Illustration: Fig. 54.]

=Bleach Pump.=--In the accompanying engraving (Fig. 54) is shown
a pump, manufactured by Bryan Donkin and Co., which is arranged
expressly for the purpose of pumping up bleach-liquor. Each pump
is all self-contained, and merely requires a drum and strap to
drive it. The live and dead riggers upon the pump allow it to be
started and stopped at pleasure. "In all paper-mills," say the
manufacturers, "the bleach-liquor should be used over and over
again, not only to save bleach, which amounts to a considerable sum
in the course of a year, but also to keep the paper clean."


[Illustration: Fig. 55.]

[Illustration: Fig. 56.]

=Three-Roll Smoothing-Presses.=--The engraving (Fig. 55) shows a
damp smoothing-press, with rolls for smoothing the paper between
the two sections of drying cylinders of a paper-machine. The makers
are Messrs. Bryan Donkin and Co. A three-roll smoothing press, for
smoothing the paper at the end of a paper-machine, also by the same
makers, is shown in Fig. 56.


[Illustration: Fig. 57.]

=Back-water Pump.=--The engraving (Fig. 57) shows a pair of back or
size-water pumps, manufactured by Bertrams, Limited. The barrels
are of cast-iron, lined with copper. The suction and discharge
valves are each contained in a chamber with covers, so that every
valve could be easily got at by simply releasing the cover. The
valve-seats are of brass, with brass guards and rubber clacks.
The plungers are of brass, with cup-leathers. All is fitted up
on a cast-iron sole-plate, with tall standards, disc-cranks, and
driving-pulley between frames.


[Illustration: Fig. 58.]

=Web-glazing Calender.=--Fig. 58 represents Bertrams' web-glazing
calender, with steam-engine attached. The illustration shows the
machine in front elevation. The steam-engine is specially designed
for this class of work, having two cylinders 10 inches in diameter
by 16 inches stroke, fitted on a double-hooded sole-plate, with
double-throw crank-shaft, fly-wheel, two eccentrics, wrought-iron
piston-rods, connecting-rods and valve-rods, steam and exhaust
branch pipes with one inlet valve, lubricators, and the cylinders
cased with teak legging and brass hoops.


[Illustration: Fig. 59.]

=Reeling Machine.=--One form of reeling machine manufactured by
Bertrams, Limited, is shown in Fig. 59, and is used for slitting
and re-reeling webs of paper, especially where large webs are
requisite for web-calendering, web-printing, and suchlike. The reel
of paper from the paper-machine is placed on a sliding-carriage
arrangement, the brackets of which are planed and fitted to a
planed sole, with wedge or dove-tail corners, and controlled by
screws, hand-wheel, etc., so that the reel can quickly and easily
be moved forward or backward to suit any unequal reeling that may
have taken place on the paper or the machine. A hot cast-iron is
provided for mending breaks in the web, and a measuring-roll and
counter is also applied. The machine has an important application
of drawing-in or regulating rolls of cast iron, with arrangement
of expanding pulley for regulating the tension on the paper.
Slitting-knives, regulating, dancing, or leading-rolls, of cast
iron, etc., are applied for separating the edges and guiding the
webs after they are slit. The reeling is performed by a 3-feet
diameter drum, cross-shafts, and arms, to which regulating heads
are fitted, so that several webs can be run up at one operation.


[Illustration: Fig. 60.]

=Web-Ripping Machine.=--This machine, which is manufactured
by Messrs. Bentley and Jackson, is shown in Fig. 60, and is
constructed to divide webs of paper into two or more widths.
It consists of two brass bearings on cast-iron standards, with
screw adjustments, a break-pulley and friction-regulator, all
mounted on cast-iron slides, movable transversely by means of a
screw, geared-wheels, shaft and hand-wheel; a wood guide-roll,
about 7 inches diameter, with wrought-iron centres, carried by
brass bearings with screw adjustment; three skeleton drums, each
2 feet in diameter, on wrought-iron shafts, carried by brass
bearings, and driven by spur-wheels and pinions; two wrought-iron
leading-rolls, with brass bearings and cast-iron stands; a pair
of strong wrought-iron ripper shafts with circular steel knives,
bosses, springs, and collars; cast-iron stands and brass bearings,
spur-wheels and driving-pulley; two (or more) changeable wood
drums 1 foot 6 inches in diameter, each with wrought-iron shaft
and catch-box, carried by brackets fitted with brass steps for
easily changing, driven by wrought-iron shafts with pedestals and
friction-pulleys, 2 feet in diameter, with regulating screws and
lock-nuts, all carried by strong cast-iron framing and standards,
and driven by a wrought-iron driving-shaft, with fast and loose
driving-pulleys, strap-fork and levers for starting and stopping.


[Illustration: Fig. 61.]

=Roeckner's Clarifier.=--In this apparatus, of which an
illustration is given in Fig. 61, Mr. Roeckner has taken advantage
of the fact that if a column of liquid is ascending very slowly and
quietly within a vessel, it will not be able to carry up with it
the solid particles which it contains, which will gradually fall
back and sink to the bottom under the action of gravity, without
ever reaching the top of the vessel, provided this be of sufficient
height. The illustration shows the arrangement of the apparatus on
a small scale; the liquor to be clarified is run into a well or
reservoir _b_; into this dip a wrought-iron cylinder _c_, which is
open at the lower end, but hermetically closed at the top by means
of the casing _d_. From this casing air can be withdrawn through a
pipe, _h_, by means of an air-pump _i_. As soon as this is done the
liquid will begin to ascend the cylinder _c_, and if the height of
this is below that to which the water will rise at the atmospheric
pressure (say 25 feet), the liquid will ascend until it fills
the cylinder and the casing. Into the pocket at the side of the
casing there dips a pipe _g_, which passes out through the opposite
side of the casing, descends below the level of the water in the
tank, and ends in a discharge-cock. When this cock is opened, the
cylinder _c_ and the pipe _g_ form between them a syphon, of which,
however, the descending leg is of very small diameter compared with
the ascending leg. In consequence, the liquid will rise in the
cylinder _c_ very slowly. The sediment it contains will sink back
and collect in the bottom of the tank _b_, and clear water will
flow out at the outlet. A sludge-cock at the bottom of the tank
allows the solid matter to be drawn off at intervals and conveyed
to any convenient place for drying, etc.[30] For drawing clear
water from a river, the clarifier would simply be placed in the
river, dipping 2 or 3 inches into it below the lowest water-level.
The clear water will then be drawn through the clarifier, while
the heavier matters will fall down and be carried away by the
river current. It is stated that this has proved a great advantage
to a paper-mill which used a river, and had, prior to its use,
been much troubled through the dirt being pumped with the water.
The clarifier to receive the waste from paper-machinery, or from
washings in the engines, can be placed in any convenient corner,
and by its action the water can be re-used, and the otherwise lost
fibres collected, without its action ever being stopped.


[Illustration: Fig. 62.]

=Marshall's Perfecting Engine.=--This engine, a longitudinal
section of which is shown in Fig. 62, has been introduced into
this country by Messrs. Bentley and Jackson, and is described
in _Industries_[31] as follows:--"The machine, which is the
invention of Mr. F. Marshall, of Turner's Falls, Mass., U.S.A.,
is used in one of the processes of paper manufacture, and has for
its purpose the more effectual drawing of the pulp fibre, the
clearance of knots from the pulp previous to its delivery on to the
paper-making machine, and the saving of time in the treatment of
the material. As will be seen in the illustration (Fig. 62), the
machine consists essentially of a cast-iron conical casing, bored,
and fitted with about two hundred elbowed steel knives, G, placed
in sections. At the large end of this conical casing is placed a
movable disc, also fitted with about two hundred and ten steel
knives, F, and capable of adjustment by means of a screw, worm,
worm-wheel, and hand-wheel, E. The revolving cone and disc are of
cast iron, fitted with straight steel knives firmly keyed upon a
hammered iron shaft, and carefully balanced to prevent vibration.
The knives of the revolving cone and disc are brought into contact
with the stationary knives by means of the hand-wheel, E, and
the disc-knives can be independently adjusted by means of the
hand-wheel C, which actuates a screw on the conical casing by means
of the worm and worm-wheel shown. The machine is driven by means
of a pulley A, and the whole machine is mounted on a cast-iron
base-plate. The pulp material enters the engine in the direction
indicated by the arrow, B, at the small end of the cone, and is by
the rotary and centrifugal action of the revolving cone, propelled
to its large end, and during its passage is reduced to a fine pulp
by the action of the knives. It then passes through the knives,
F, of the stationary and rotating discs, by which the fibres are
further crushed or split up, all knots or strings rubbed out, and
the pulp effectually cleared previous to its exit through the
passage D." We are informed that the machine is capable of treating
from 900 lbs. to 1,200 lbs. of pulp per hour. The power required to
drive it is estimated at from 40 i.h.p. to 50 i.h.p. when making
300 revolutions per minute. This, however, is dependent on the
amount of friction caused between the surfaces of the fixed and
revolving knives. The flow space occupied is 12ft. 6in. in length,
and 4ft. in width. The perfecting machine, in its complete form, is
shown in Fig. 63.

[Illustration: Fig. 63.]



CHAPTER XVIII.

_RECOVERY OF SODA FROM SPENT LIQUORS._

  Recovery of Soda.--Evaporating Apparatus.--Roeckner's
  Evaporator.--Porion's Evaporator--American System of Soda
  Recovery.--Yaryan Evaporator.


=Recovery of Soda.=--Probably one of the most important
improvements in modern paper-making, at least from an economical
point of view, is the process of recovering one of the most costly,
and at the same time most extensively used, materials employed in
the manufacture--soda. While not a great many years since (and
in some mills is still the case even now), it was customary to
allow the spent soda liquors resulting from the boiling of various
fibres to run into the nearest rivers, thus not only wasting a
valuable product, but also polluting the streams into which they
were allowed to flow, means are now adopted by which a considerable
proportion of the soda is recovered and rendered available for
further use. The means by which this is effected are various,
but all have for their object the expulsion of the water and the
destruction of the organic matters dissolved out of the fibrous
substances in the process of boiling with caustic soda solutions.
One of the main objects of the various methods of recovering the
soda from spent liquors is to utilise, as far as practicable, all
the heat that is generated from the fuel used, whereby the process
of evaporation may be effected in the most economical way possible.
The principle upon which the most successful methods are based is
that the flame and heat pass over and under a series of evaporating
pans, and through side flues, by which time the heat has become
thoroughly utilised and exhausted. When all the water has been
expelled, the resulting dry mass is ignited and allowed to burn
out, when the black ash that remains, which is carbonate of soda,
is afterwards dissolved out, and the alkaline liquor causticised
with lime in the usual manner. According to Dunbar, 8 cwt. of
recovered ash and 4½ cwt. of good lime will produce 900 gallons
of caustic ley at 11° Tw. The liquor is then pumped into settling
tanks, from which it is delivered to the boilers when required.


[Illustration: Fig. 64.]

=Evaporating Apparatus.=--An ordinary form of evaporator for the
recovery of the soda is shown in Fig. 64. It consists of a chamber
A, of the nature of a reverberatory furnace, lined with fire-brick,
the bottom of which is slightly hollowed. Above this is a tank
B containing the liquor, which is run down into the chamber as
required by means of a pipe C, provided with a tap. At one end of
the chamber is a furnace D, the flame of which passes through
the chamber and over the surface of the liquor lying upon the
floor, heating the chamber, evaporating, and at last incinerating,
its contents, and at the same time warming the liquor in the
tank above, and evaporating some of its water. The products of
the combustion in the furnace, and of evaporation, pass by the
flue into a chimney, and escape thence into the air. There is a
door E in the side of the furnace near the level of the floor of
the chamber, and this is opened from time to time to enable the
workmen to stir and move about the contents of the chamber, and
finally, when the process is sufficiently advanced, to draw out
the residue. The first effect produced is the reduction of the
liquor to the consistence of tar. Later on, a white crust, which
is the incinerated material, forms on the surface, and is drawn
on one side by the workmen, so as to allow of fresh crust being
formed. When all the charge has become solid it is drawn. The
charge is usually withdrawn before the conversion into carbonate is
completed; it is then raked out into barrows and placed in a heap,
generally in a shed or chamber, open on one side, but sometimes in
a closed brick-chamber or den, where the combustion continues for
several weeks. The result is the fusion of the material into a grey
rocky substance, which consists chiefly of carbonate and silicate
of soda.

Various modifications of the esparto evaporator and calciner have,
however, been introduced since the recovery of soda has become more
general, and are in use at various works, all having for their
main object the economising of fuel and the utilising of the waste
heat of the fire, which in the old-fashioned calciner goes up the
chimney and is lost. The leading principle, of all of them is to
use the waste heat in concentrating the liquor preparatory to its
being run into the part where the calcination is to be effected.
This is done by so extending and widening out the flue as to cause
the heated air and flame, after they have performed their function
in the calcination, to pass over or under their layers of liquor,
lying upon shelves or floors in such a way that the liquor shall
become more and more concentrated as it approaches the calciner by
successive steps or gradations.[32]--_Dr. Ballard._


[Illustration: Fig. 65.]

=Roeckner's Evaporator.=--This apparatus, an illustration of which
is shown in Fig. 65, is thus described by Dr. Ballard, medical
officer of the Local Government Board, who was specially appointed
by the board to investigate the effluvium nuisances which arise
in connection with certain manufacturing industries. "In this
apparatus there is above the calcining floor a series of shelves
or shallow pans, alternating in such a manner that the liquor
flowing from the tank above into the uppermost of them, flows,
after a partial evaporation, over the edge of the shelf into the
shelf or shallow pan next below, and in this way from shelf to
shelf, still becoming more and more concentrated until it reaches
the final floor, over which the flame from the actual fire plays,
and where the first part of the calcination is effected. The
heated air, in passing to the chimney, passes over each of these
shelves in succession, heating them and concentrating the liquor
upon them. There is between the lower shelves an arrangement for
causing the liquor to pass from the upper to the lower by means of
a pipe, instead of its running over the edge. At the top of all
is a covered tank, where the temperature of the liquor is raised
before it is run into the evaporator. In order to promote the
heating of the liquor in this tank, the lower part of the tank is
made to communicate by side pipes with tubes passing across the
evaporator near the fire, as, for instance, at the bridge and at
the further end of the calcining floor. In this way a circulation
of liquor is set up which serves to heat the liquor in the tank
more effectually. A pipe from the top of the tank leads to the
chimney-shaft, conducting any vapours into it. As the incinerated
crust forms it is raked on one side, and when sufficient of it has
accumulated it is drawn to an opening (provided with a damper) at
the side or end of the floor, and discharged down this opening
into a brick chamber below, which is inclosed by iron doors, and
from which a flue conducts the vapours that arise during the final
fusion through the fire in such a way as to consume them." By
recent improvements Mr. Roeckner has constructed an apparatus for
condensing and rendering inoffensive the vapours eliminated from
the liquor during its evaporation on the successive shelves of his
evaporator.


=Porion's Evaporator.=--This evaporator and incinerating furnace
much resembles in principle an ordinary reverberatory furnace,
except that it is provided with paddle agitators, which project the
liquid upwards, causing it to descend in a spray, thus increasing
the surface of the liquid coming in contact with the hot air and
current of smoke traversing the furnace. By this method the expense
of fuel is greatly reduced. The residue is in a state of ignition
when it is withdrawn from the furnace, and is piled in heaps so
that it may burn slowly. When the combustion is complete, the
resulting calcined mass is treated with water, and the carbonate
of soda formed is afterwards causticised in the usual way. About
two-thirds of the soda is thus recovered.


=The Yaryan Evaporator.=--Mr. Homer T. Yaryan, of Toledo, Ohio,
U.S.A., has introduced some important improvements in evaporating
apparatus, which have been fully recognised in America, and appear
to have been attended with success. The principle involved is that
of multiple effects, in which the evaporation takes place while
the liquid is flowing through heated coils of pipe or conduits,
and in which the vapour is separated from the liquid in a chamber,
at the discharge end of the coils, and is conducted to the heating
cylinder surrounding the evaporating coils of the next effect,
from the first to the last effect. The objects of the invention
are: (1) to provide extended vaporising coils or conduits and
increased heating surface for each liquid feed supply in the
heating cylinders, and provide improved means for feeding the
liquid, whereby each set or coil of vaporising tubes will receive
a positive and uniform supply of liquid without danger of the
feed ducts being clogged by extraneous matter; (2) to positively
control the amount of liquid fed by the pump to the evaporating
coils, and make it more uniform than heretofore, regardless of the
speed of the pump; (3) to provide improved separating chambers at
the discharge ends of the vaporising coils so as to better free
liquid and solid particles from the vapours; (4) to provide for
the successful treatment of the most frothy liquids by causing
the vapours carrying solid and liquid particles to pass through
catch-all chambers, where they are arrested and precipitated and
then returned to the evaporating coils; (5) to secure a more
positive flow and circulation of liquid from the evaporating
cylinder of one effect to another, under the influence of a better
vacuum than heretofore in multiple-effect vacuum evaporating
apparatus; (6) to provide for transferring a better concentrated
liquid into the separating chamber containing cooler concentrated
liquid in direct connection with the condenser and vacuum pump, so
as to equalise the temperature of the two liquids, and then draw
off both by one tail pump.

[Illustration: Fig. 66.]

[Illustration: Fig. 67.]

[Illustration: Fig. 68.]


[Illustration: Fig. 69. Fig. 70. Fig. 71.]

[Illustration: Fig. 72. Fig. 73. Fig. 74.]

The present invention comprises a series of important improvements
on an apparatus described by Mr. Yaryan in a former English patent,
No. 14,162 (1886), and covers a number of important modifications
in construction, whereby improved results are secured. It is only
necessary, therefore, to give the details of the new patent,
No. 213 (1888), since it embodies the latest improvements which
practical working of the apparatus has suggested. In reference to
the accompanying illustrations the following details are given:
Fig. 66 represents a side elevation of the apparatus; Fig. 67,
the front elevation; Fig. 68, a top plan view; Fig. 69, a vertical
section of a cylinder showing the evaporating coils and separating
chamber; Fig. 70 is a horizontal section; and Fig. 71, a vertical
section of the separating chamber shown in Fig. 69, both on
reduced scale; Fig. 72 is a broken section of the cylinders for
showing the connections of the liquid pipe from the first to the
third effect evaporator; Fig. 73 is a rear end view of a cylinder
with manifold, the feed pump and a sectional view of the feed
box and supply devices; Fig. 74 represents a sectional view, on
enlarged scale, of the manifold and a feed duct; Fig. 75 is an
inside view of a return bend-head; Fig. 76 an inside view of a
section of the head; Fig. 77, a vertical cross section thereof
on enlarged scale, and showing the partitions forming cells
for connecting the ends of the evaporating tubes; Fig. 78 is a
vertical longitudinal section of a catch-all chamber; Fig. 79, a
cross section thereof; Fig. 80 is a vertical longitudinal section
of new form of separating chamber; and Fig. 81 represents a side
view and Fig. 82 an end view of the cylinders for showing the pipe
connection between the separating chambers of the third and fourth
effect evaporators.

[Illustration: Fig. 75. Fig. 76. Fig. 77.]

[Illustration: Fig. 78. Fig. 79. Fig. 80.]

The evaporating cylinders are mounted upon a framework Y, supported
upon columns X X, or other suitable supports. The apparatus is
shown arranged as quadruple effect, with four connected cylinders,
but multiple effect apparatus may be constructed with an increased
number of cylinders up to ten or twelve. The heating cylinders
B^1 B^2 B^3 B^4, containing the evaporating tubes or coils, are
preferably arranged in the same horizontal plane, and are provided
at the discharge ends of the evaporating coils with separating
chambers, A^1 A^2 A^3 A^4, of enlarged diameter, and at the supply
ends of the coils with the coils with return bend ends, C^1 C^2
C^3 C^4. From each separating chamber, A^1, A^2, valve pipe D^1
D^2 D^3 leads into the shell of the next heating cylinder, as
B^2, B^3, B^4, and vapour pipe D^4 leads from the last separator
A^4 to the condenser H, and the vacuum pump H^1. A cylindrical
catch-all chamber E^1, E^2, E^3, E^4, is connected in each vapour
pipe between each separator and each successive heating cylinder,
as shown in Figs. 66, 67, and 68, and in detail in Fig. 75. Gauge
glass and liquid receiving chambers, G^1, G^2, G^3, G^4, connect
with the bottom of each separating chamber for receiving the
liquid as it is separated from the vapour, and a gauge glass _g_
is applied to each of such chambers. Liquid discharge and transfer
pipes _t_, _t^1_, having valves _h_, _h^1_, as best shown in Figs.
66, 68, and 72, lead respectively from chambers G^1, G^2, of the
first and second effect to the manifold feed pipes leading into the
cylinders B^3, B^4, of the third and fourth effect for the purpose
hereafter described. The main steam supply pipe F, having a safety
valve _f_ and stop valve _f^1_, Figs. 66, 67, and 68, connects with
the heating cylinder B^1 of the first effect. The evaporating tubes
1, 2, 3, 4, 5, are expanded or otherwise secured in the tube sheets
_d_ and _e″_ at opposite ends of the cylinders, and are properly
connected at the ends in sets of five to form coils. The outer rear
return-bend head C^1 C^2, etc., are provided on their insides with
numerous short intersecting partition plates _c_, forming single
and double cells, properly arranged for connecting the evaporating
tubes in sets of five, as shown in Figs. 75, 76, 77.

[Illustration: Fig. 81. Fig. 82.]

The heads are pierced with holes _c′_ for connecting the liquid
supply pipes M of the manifolds L. The inner return-bend head T in
the separating chambers are formed like heads C^1 C^2, etc., with
intersecting partition plates _x_, and are provided with discharge
openings _t″_ for every fifth tube, as shown in Fig. 69. Tube sheet
_d_ is made of considerably larger diameter than cylinders B^1
B^2, etc., and acts as a vibrating diaphragm, to accommodate the
expansion and contraction of the tubes. The separating chambers may
be constructed with dash plates _b_ _b_, two or more in number,
having openings _g′_ _g′_ alternately upon opposite sides for the
passage of vapour, and opening _a′_ at the bottom for the passage
of liquid, as shown in Fig. 80. Here a tube sheet _z_ is provided
near the openings of the evaporating tubes, and in such sheet are
set numerous small horizontal tubes _n_, which discharge against a
vertical arresting plate _b′_ set near their open ends. Water and
solid matter are impelled against the plate and thereby arrested
and caused to flow down to the bottom of the chamber. The liquid
feed apparatus consists of a supply tank K, stand-pipe J, feed box
K^1, double pump I, manifold L, and connecting pipes and valves.
The liquid to be evaporated flows from tank K, through pipe _k_, to
stand-pipe J and box K^1, the flow being constant and uniform, and
of the desired quantity, by means of a valve _k′_ having a lever
handle _r′_ which is connected by a cord or chain passing over a
pulley _j_ with float _q_ in stand-pipe J. The valve opening in
pipe _k_ being properly adjusted by means of the float, etc., the
liquid is admitted to the stand-pipe J while the column of liquid
is automatically maintained at any desired height and pressure
regardless of the quantity in the supply tank, by means of the
float _q_, which, as it rises, tends to close valve _k′_, and as
it falls, to open the valve. From the bottom of the stand-pipe J,
nozzle _j′_ discharges a constant and uniform stream of liquid into
feed box K^1. The suction pipe I″ of pump I extends into box K^1,
where it terminates in a turned-down nozzle provided with valve _i_
having a lever handle and float _z_. As a given amount of liquid is
constantly running into the box, should the pump run too fast the
float lowers, partially closing the valve and lessening the amount
of liquid drawn at each stroke of the pump, and preventing air from
being drawn in, since the end of the suction pipe is always sealed
by the liquid. The liquid is forced by pump I into the manifolds
L, from which it flows through the contracted ducts _l_ into the
enlarged feed pipes _m_, as shown in Figs. 73 and 74. Ducts _l_ are
of about one-half inch diameter, and the upper and lower sections
thereof are connected by a union coupling, one portion of which
_l′_ has a reducer with opening one-quarter inch diameter, more or
less, according to the amount of liquid it is desired to feed.

The catch-all chambers E^1 E^2, etc., Figs. 66, 78, and 79, are
provided each at its inlet end _e_, with tube sheet _o_ extending
across its diameter a short distance in front of the opening of
vapour pipe D^1, and in such sheet are fixed numerous longitudinal
tubes _p_ extending to near the opposite head _e′_, so that vapours
carrying watery or solid particles are impelled against the head
and arrested. Liquid and solid matter, arrested in the catch-all
chambers, flow through pipes _v v′_ _v″_ down into the fluid
transfer pipe _t t′_ (Figs. 67, 68, and 72), and thence into the
evaporating coils and through pipe _v‴_ directly to the tail pump
W, Fig. 67. By use of the catch-all chambers the most frothy
liquids can he readily and economically managed. A liquid transfer
pipe _s_, having a valve _h″_, leads directly from receiving
chamber G^3 of the third effect to the separating chamber A^4 of
the fourth effect, the latent heat being carried off in the vapours
drawn by the vacuum pump H^1 into the chamber H, and the finished
liquid of both effects is drawn off through pipe _w_ by one and
the same tail pipe pump W. The water of condensation accumulating
in the heating cylinders B^1 B^2, etc., is transferred from one
to the other through connecting pipes _u u′ u″_ having valves
_y_, shown in Figs. 66, 67, and 68; and finally from cylinder B^4
through pipe _u‴_ directly into condenser H. The specification of
the patent, which those interested will do well to consult, next
describes the operation of the apparatus.


=American System of Soda Recovery.=--Mr. Congdon gives an
exhaustive description[33] of the method of recovering soda
in the United States, from whose interesting paper we extract
the following:--The spent liquors are delivered to the Yaryan
evaporator from the pans at a density of 6° to 7° B. at 130°
F. Here they are concentrated to 34° to 42° at 140° F. At this
density they are fed into furnaces of a reverberatory type, where
they are burnt to a cherry-red heat; and the ash then raked out.
This ash, which averages 50 per cent. of soda, is weighed in iron
barrows on suitable scales, and wheeled into the leaching-room
for lixiviation. The system of leaching, as it is termed in the
States, is conducted as follows:--Iron tanks are used, with
suitable piping, that allows pumping from one tank to another, and
also to pump from any one of them up to the causticising tanks in
the alkali-room. There is also a water-line by which water may be
pumped into any of the tanks, and there is a spout used in washing
away the black ash sludge. The leaching-tanks have false bottoms
of 2in. by 2in. stuff, placed crosswise, over which is a layer of
gravel, on which lies a layer of straw, by which the liquor is
filtered. The gravel is removed every few days, and the straw
with every charge. When one of the tanks is filled with black ash,
it is "wet down" with the stored liquor (the strongest of the
stored weak liquors), and also with the strongest weak liquors
from the tanks, and with weak liquors obtained from these tanks by
pumping water upon them and keeping them full. This is all pumped
up to the causticising-tank until the strength is reduced to 2°
or 1½° B. The remaining liquor is then drained into a tank known
as the "clear-liquor" tank, owing to there being no black ash in
it. The liquor from the next weakest pan is then pumped upon the
pan containing the black ash, and the next weakest liquor pumped
upon this. The weaker pans are then in succession pumped upon
the stronger, and the water pumped upon these, and thus a very
perfect washing is obtained. The sludge left behind is nothing but
charcoal, with a slight trace of carbonate of soda. Mr. Congdon
illustrates the above system thus. The tanks stand as follows:--

No. 1. Clear liquor, 1° to 2° B. (strongest).

No. 2. Black ash sludge (weaker than No. 3).

No. 3. Black ash, after sending up to causticising-tank (strongest
sludge).

No. 4. Fresh black ash.

No. 5. Weaker than No. 2 (sludge only).

No. 6. Weaker than No. 5 (sludge and weakest liquor).

The method of procedure is as follows:--

Liquor from No. 3 drained into No. 1 (now full).

No. 6 pumped on to No. 2 (No. 6 sludge thrown away).

Liquor from No. 2 drained upon No. 3.

Water put on No. 5.

No. 5 pumped upon No. 2 (No. 5 sludge thrown away).

The black ash is treated thus:--

No. 4, full of black ash, is wet down with Nos. 1, 2, and 3, and
pumped up to the causticising-tank.

Water is pumped out to Nos. 2 and 3, and then drained upon No.
4, the liquor still being pumped up from No. 4 while the water
is being pumped upon Nos. 2 and 3, which are kept full. This is
continued until the liquor tests only 2° to 1° B.

No. 4 is now drained upon No. 1.

No. 3 pumped upon No. 4, and this drained into No. 1 (now full).

No. 3 pumped upon No. 5.

Water pumped upon No. 2 (No. 2 the next to be thrown away).

No. 5 is by this time full of fresh black ash, and the same process
is carried out with No. 4.



CHAPTER XIX.

_DETERMINING THE REAL VALUE OR PERCENTAGE OF COMMERCIAL SODAS,
CHLORIDE OF LIME, ETC._

  Examination of Commercial Sodas.--Mohr's Alkalimeter.--Preparation
  of the Test Acid.--Sampling Alkalies.--The Assay.--Estimation of
  Chlorine in Bleaching Powder.--Fresenius' Method.--Gay-Lussac's
  Method.--The Test Liquor.--Testing the Sample.--Estimation of
  Alumina in Alum Cake, etc.


In a manufacture such as paper-making, which involves the
consumption of enormous quantities of materials of variable
quality, as soda ash, caustic soda, and bleaching powder, for
example, it will be readily seen that some means should be at the
command of the consumer who does not avail himself of the services
of a practical chemist at his works, by which he can ascertain the
_actual_ value of the various substances he uses. An art which, up
to a certain point in its progress, is mainly a chemical operation,
it would undoubtedly be more safely and economically conducted when
supervised by persons well acquainted with chemical principles
and reactions, and less dependent upon individual judgment, than
is, perhaps, too frequently the case. Under such supervision more
perfect uniformity of results--a consideration of the greatest
importance in a manufacture of this kind--would be ensured.


[Illustration: Fig. 83. Fig. 84. Fig. 85.]

=Examination of Commercial Sodas.=--The methods of determining the
percentage of real alkali in the commercial products which have
received the name of _Alkalimetry_ are fortunately of a simple
character, and such as a person of ordinary intelligence and
skill can readily manipulate and render thoroughly reliable by
exerting the necessary care. He must, however, be provided with a
few indispensable appliances, which will be described, and with
these he should make several trials upon various samples until
he finds that his results are uniform and his manipulation easy
and reliable. He will require a chemical balance,[34] capable of
weighing to the tenth of a grain; a few glass "beakers" (Fig.
83) of various sizes, capable of holding from four to eight or
ten ounces of fluid; several glass stirrers; a bottle of litmus
solution, made by dissolving litmus in hot water; books of litmus
and turmeric papers; and several glass flasks (Fig. 84) of various
sizes, capable of holding from four to eight ounces. Besides these
accessories, certain measuring instruments, termed _alkalimeters_
or _burettes_, are employed, of which either of the two following
may be employed. These instruments are of glass, and hold up to 0
or zero exactly 1,000 grains. The scale is graduated in a hundred
divisions, which are again subdivided into tenths. Bink's burette
is shown in Fig. 85, and Mohr's burette in Fig. 86. The latter,
being provided with a stand, enables the operator to add the test
liquor--with, which the burette is charged--drop by drop, when the
alkaline solution to be tested is near the point of saturation,
without engaging the hands.


[Illustration: Fig. 86. Fig. 87.]

=Mohr's Alkalimeter.=--This useful instrument (Fig. 86) and the
method of using it is thus described by Mohr:--"I have succeeded
in substituting for expensive glass stop-cocks an arrangement
which may be constructed by any person with ease, which remains
absolutely air and water-tight for an indefinite period, which
may be opened and regulated at will by the pressure of the
fingers, and which costs almost nothing. It consists of a small
piece of vulcanized indiarubber tube, which is closed by a clamp
of brass wire (Fig. 87). The ends of this clamp, which I call a
pressure-cock, are bent laterally at right angles in opposite
directions and furnished with knobs, so that when both ends are
pressed the clamp is opened, and a single drop or a continuous
current of liquid may be allowed to escape at pleasure. The
measuring-tube is a straight glass cylinder, as uniform as
possible, graduated to 0·2 or 0·1 cubic centimètres, and somewhat
contracted at its lower end, so as to fit into the indiarubber
tube. A small piece of glass tube inserted below the pressure-cock
forms the spout. The pressure-cock has the advantage of not
leaking, for it closes itself when the pressure of the fingers
is removed. The measure, furnished with the pressure-cock, is
fastened upon an appropriate stand, which can be placed at any
required height. When used, it is filled above the zero point with
test liquor, the cock opened for an instant, so as to let the
air escape from the spout, and the level of the solution is then
adjusted. This is done by bringing the eye level with the zero
point, and applying a gentle pressure to the cock until the liquid
has sunk so low that the inferior curve of the liquid touches the
graduation like the circle of a tangent; the cock is then closed,
and at the same moment the liquid remains at zero, and continues to
do so for weeks if evaporation is prevented. The test-measure being
normally filled, the experiment may be commenced; this is done
sitting, while the filling of the measure is done standing.

"The weighed sample of alkali is first placed in a beaker-glass,
and the test-liquor is allowed to flow into it by gently pressing
the cock. Both hands are set at liberty, for when the pressure-cock
is released it closes of itself. The volumetric[35] operation may
be interrupted at pleasure, in order to heat the liquid, shake it,
or do whatever else may be required. The quantity of liquid used
may be read off at any moment, and in repeating an experiment,
the limit of the quantity used before may be approached so near
that the further addition of liquid may be made drop by drop."
The test-acid to be used _volumetrically_--that is, with the
alkalimeter, has a specific gravity of 1·032 at 60° F., and 1,000
grains by measure contain exactly 40 grains of real or anhydrous
(that is, without water) sulphuric acid.

The chemical principles involved in the process of alkali-testing
may be thus briefly stated:--According to the laws of chemical
combination defined by the atomic theory of Dalton, all substances
combine in _definite_ proportions or "equivalents"; thus, 1 part by
weight of _hydrogen_ combines with 8 parts by weight of _oxygen_
to form water. The equivalent number of hydrogen, therefore, is
1, and of oxygen 8, and that of water 9. Again, 3 equivalents of
oxygen combine with 1 equivalent of sulphur (16) to form sulphuric
acid; thus, sulphur 16, oxygen 24, equals anhydrous sulphuric
acid 40; therefore 40 is the _equivalent_ or combining number of
this acid, and it cannot be made to unite with alkalies or other
bases in any other proportion. For example, 40 _grains_ by weight
of _pure_ sulphuric acid will neutralise exactly 53 grains of
_dried carbonate of soda_, 31 grains of _pure anhydrous soda_, or
40 grains of _hydrate of soda_ (caustic soda). This being so, it
is only necessary to have exactly 40 grains of _real_ sulphuric
acid in 1,000 grains of water to form a _test-acid_, which, when
employed to neutralise an alkaline solution, will show, by the
proportion of dilute acid used to saturate the alkali, the absolute
percentage present in the sample.


=Preparation of the Test-Acid or Standard Solution.=--As there is
some trouble involved in the preparation of the test-liquor, it
is advisable to prepare a sufficient quantity at a time to last
for many operations. It may be readily made by mixing 1 part of
concentrated sulphuric acid with 11 or 12 parts of _distilled
water_, the mixture being made in what is termed a "Winchester"
bottle, which holds rather more than half a gallon, and is provided
with a glass stopper. The acid solution must be _adjusted_ or
brought to the proper strength after it has cooled down to 60°
F.; and it should be _faintly tinged_ with litmus, which will
give it a pinkish hue. The acid, to be of the proper strength,
should _exactly_ neutralise 53 grains of pure carbonate of soda,
previously calcined at a red heat, or 31 grains of pure anhydrous
soda. To prepare the anhydrous carbonate of soda, a few crystals of
carbonate of soda are placed in a Berlin porcelain crucible, and
this must be heated over a spirit-lamp or Bunsen burner. When all
the water of crystallisation has become expelled, the calcination
is continued until the mass is at a bright red heat, when the
vessel may be allowed to cool. 53 grains of the calcined carbonate
are now to be carefully weighed, and next dissolved in a glass
beaker, in about 2 ounces of distilled water. The alkalimeter is
now to be charged with the test-acid to the level of zero, and (if
Mohr's burette be used) the beaker containing the alkaline solution
is to be placed upon the stand immediately beneath the exit-tube.
Now press the knobs of the pressure-cock, and allow a portion
of the liquor to flow into the beaker. When the effervescence
which immediately sets up subsides, make further additions of the
test-liquor from time to time, until the effervescence becomes
sluggish, at which period the acid must be added with greater
caution. When the solution approaches saturation it acquires a
purplish tint (due to the litmus with which the acid is tinged),
which it retains until the point of saturation is reached, when it
suddenly changes to a pink colour. After each addition of the acid
the solution should be stirred with a thin and clean glass rod;
and before the final change from purple to pink, the end of the
glass rod should be applied to a strip of blue litmus paper, when,
if the moistened spot touched assumes a red colour, the saturation
is complete; if, on the contrary, the paper is unchanged, or has a
violet or reddish hue, add the test-liquor, one or two drops at a
time, with continued stirring, until a drop of the solution applied
with a glass rod reddens litmus paper, when the saturation is
finished. If any test-liquor remain in the burette, this indicates
that there is excess of acid in the test-liquor; consequently more
distilled water must be added to the bulk, the burette emptied
and refilled with the reduced liquor, and another 53 grains of
anhydrous carbonate of soda treated as before, until 1,000 grains
of the acid liquor _exactly_ neutralise the solution. Should the
whole contents of the burette in the first trial be used before
saturation is complete, a little more sulphuric acid must be put
into the Winchester or test-acid bottle, and a 53-grain solution
of carbonate of soda treated as before. A very little practice
will enable the operator to adjust his test-liquor with perfect
accuracy; and, to prevent mistakes, the bottle should be labelled
"Test-acid," and always be kept closed by its stopper.


=Sampling Alkalies.=--Soda-ash of commerce is usually packed in
wooden casks, and in order to obtain a fair average sample from a
large number of these casks, which may represent one consignment,
it is important to take small samples, as near the centre of each
cask as possible, from as many of the casks as time will permit.
Each sample, as drawn from the cask, should be at once placed
in a rather wide-mouthed bottle furnished with a well-fitting
cork. Each sample should be numbered and marked with the brand
which distinguishes the cask from which it was taken. The duty
of sampling should be placed in the hands of a person of known
integrity and intelligence.

When about to test a sample of soda-ash, the contents of the bottle
should first be emptied upon a sheet of dry paper, and the larger
lumps then crushed to reduce the whole to a coarse powder, and
this must be done as quickly as possible to prevent absorption of
moisture from the atmosphere. 100 grains of the alkali must now
be accurately weighed and put into a glass flask (Fig. 84), and
the remainder of the alkali returned to the bottle and the vessel
securely corked. About half an ounce of distilled water is then to
be put into the flask and gentle heat applied, with an occasional
shaking, until the alkali is all dissolved. The flask is then to
be set aside for a few minutes, until any insoluble matter present
has subsided, when the clear liquor is to be carefully poured into
a beaker glass; the sediment must be washed several times with
small quantities of distilled water, and the washings added to
the solution in the beaker. This washing is of great importance
and must be performed several times, or until the last washing
liquor produces no effect upon yellow turmeric paper, which even
slight traces of alkali will turn a brown colour. So long as this
brown tint is given to the turmeric paper the presence of alkali
is assured, and the washing must be continued. It is important,
after each washing, to pour off the last drop of the liquor above
the sediment, by which the operation is more effectual, and is
effected with less water than when this precaution is not observed.
In order to ensure perfect accuracy in the result, every particle
of the washings must be added to the contents of the beaker-glass
in which the assay is to be made.


=The Assay.=--The alkalimeter is first to be filled with the
test-acid exactly to the line 0 or zero of the scale as described,
and the beaker containing the solution to be tested then placed
immediately beneath the dropping tube of the instrument; a thin
glass rod should be placed in the beaker as a stirrer. The acid
liquor is then allowed to flow gradually into the alkaline
solution (which should be repeatedly stirred with the glass rod),
by pressing the knobs of the pressure-cock, until the solution
assumes a purple tint, which it will retain until the exact point
of saturation has been arrived at, when, as before stated, it
will suddenly change to a pink colour. Before the latter stage is
reached the beaker should be placed over a spirit lamp or Bunsen
burner, and the liquid heated to expel the carbonic acid which is
evolved, and partly absorbed by the solution during the process of
saturation. When the neutralisation is complete, the alkalimeter
is allowed to repose for a few moments, so that the acid liquor
may drain from the interior of the glass tube into the bulk of the
fluid, and the quantity of test-acid used is then determined by
reading off the number of divisions of the alkalimeter that have
been exhausted, every one of which represents 1/100th part, or 1
per cent. of _alkali_, whenever the _equivalent weight_ is taken
for assay. Every 1/10th part of an alkalimeter division represents
1/10th of 1 per cent., and the result is thus obtained without
the necessity of any calculation. The following table shows the
_equivalent_ or combining proportions of soda with 40 grains of
real (that is, anhydrous) sulphuric acid:--

                                   Are
                                equivalent
                                   to
  40 grains of sulphuric acid      }  31 grains soda (anhydrous).
  1,000 grains of dilute           }  40 grains hydrate of soda (pure
    sulphuric acid (sp. gr. 1·033) }    caustic soda).
  1,000 grains of dilute           }  53 grains carbonate of soda
    sulphuric acid (water-grain    }    (anhydrous).
    measure) sp. gr. 1·032         }  143 grains crystallized
                                   }    carbonate of soda.

Mr. Arnot recommends the following method for alkali testing: "The
sample, which should be a fair average of the drum or cask from
which it is drawn, should, in the case of caustic soda, be quickly
crushed into small fragments, and returned to the stoppered bottle
in which it was collected for testing. It need not be finely
ground, and, indeed, should not be, as it very readily attracts
moisture from the air. The contents of the drum are usually pretty
uniform, and the crushing recommended will give the operator
a sample quite fit to work upon. Samples of soda-ash and soda
crystals will, of course, be fairly representative of the casks
from which they are drawn. One hundred grains of the prepared
sample must be weighed out upon a watch-glass or slip of glazed
paper, and transferred to a porcelain basin, with at least half a
pint of boiling water. The watch-glass is preferable for caustic
soda, and the weighing in the case of that agent must be done
expeditiously. While the sample is dissolving the burette will be
charged with the standard acid. To the soda solution a few drops
of solution of litmus, sufficient to colour it distinctly, will
be added. The acid will then be run into the blue soda liquor;
at first, within reasonable limits, this may be done rapidly,
but towards the close of the operation the acid must be added
cautiously, and the solution kept well stirred. In the case of
caustic, when the blue has distinctly changed to red, the operation
may be considered completed, and the measures may be read off the
burette; and this is, without calculation, the result required.
When the soda in the sample is a carbonate, the blue colour of the
litmus will be changed to pink before all the soda is neutralised,
owing to a portion of the liberated carbonic acid remaining in
the solution; this must be eliminated by placing the basin over a
Bunsen burner and boiling the solution. The blue colour will thus
be restored, and more acid must be added, repeating the boiling
from time to time, until the red colour becomes permanent. It is
sometimes necessary to filter the soda solution before testing;
this applies specially to recovered soda, and, although in a less
degree, to soda-ash." When the soda solution is filtered, it will
be necessary to thoroughly wash out the liquor absorbed by the
filtering paper, the washings being added to the bulk of the liquor
as before. The best plan is to allow the soda solution to stand
for some time until all the sediment has deposited, and then to
pour off as much of the liquor as possible, and then to wash the
sediment into a very small filter, in which it will receive further
washing, until no trace of alkali can be detected in the last wash
water.


=Estimation of Chlorine in Bleaching Powder.=--It is desirable that
the manager or foreman of a paper-mill should have at his command
some ready means by which he may test the percentage of chlorine
in samples of bleaching powder, or chloride of lime, delivered at
the mill, not alone to enable him to determine the proportions to
be used in making up his bleaching liquors, but also to ensure his
employers against possible loss in case of inferior qualities being
delivered at the mill. Bleaching powders being purchased according
to percentage, it is absolutely necessary that the purchaser should
have this determined to his own satisfaction before either using
or paying for the material. Good chloride of lime should contain
35 per cent. of available chlorine, but the powder should not be
accepted which contains less than 32 per cent. There are several
methods of estimating the percentage of chlorine in bleaching
powder, which is composed of hypochlorite of lime, chloride of
calcium, and hydrate of lime, the latter substances being of no
service in the bleaching process.

According to Fresenius, in freshly prepared and perfectly normal
chloride of lime, the quantities of hypochlorite of lime and
chloride of calcium present stand to each other in the proportion
of their equivalents. When such chloride of lime is brought into
contact with dilute sulphuric acid, the whole of the chlorine it
contains is liberated in the elementary form. On keeping chloride
of lime, however, the proportion between hypochlorite of lime
and chloride of calcium gradually changes: the former decreases,
the latter increases. Hence from this cause alone, to say nothing
of original difference, the commercial article is not of uniform
quality, and on treatment with acid gives sometimes more, and
sometimes less, chlorine. As the value of bleaching powder depends
entirely upon the amount of chlorine set free on treatment with
acids, chemists have devised very simple methods of determining the
available amount of chlorine in any given sample, these methods
having received the name of _chlorimetry_. The method of Fresenius
is generally considered both practicable and reliable.


=Fresenius' Method= of preparing the solution of bleaching powder
to be tested is as follows:--Carefully weigh out 10 grains of
the sample, and finely triturate it in a mortar with a little
cold water, gradually adding more water; next allow the liquor to
settle, then pour the liquid into a litre flask, and triturate
the residue again with a little water, and rinse the contents of
the mortar carefully into the flask, which should then be filled
with water up to the graduated mark. Now shake the milky fluid
and proceed to examine it while in the turbid state; and each
time, before measuring off a fresh portion, the vessel must be
again shaken to prevent the material from depositing. The results
obtained with the solution in its turbid condition are considered
more accurate and reliable than when the clear liquid alone is
treated, even though the deposit be frequently washed. This may be
proved, Fresenius says, by making two separate experiments, one
with the decanted clear liquor, and another with the residuary
turbid mixture. In an experiment made in his own laboratory
the decanted clear fluid gives 22·6 of chlorine, the residuary
mixture 25·0, and the uniformly mixed turbid solution 24·5. One
cubic centimètre of the solution of chloride of lime so prepared
corresponds to 0·01 gramme of chloride of lime.


=Gay-Lussac's Method.=--This method, which is known as the
_arsenious acid process_, has been much adopted for the
determination of chlorine in bleaching powders, and is conducted as
follows:--

_The Test-liquor._--This is prepared by dissolving 100 grains of
_pure_ arsenious acid in about 4 ounces of pure hydrochloric acid,
and the solution is to be diluted with water until, on being poured
into a graduated 10,000 grains measure-glass, it occupies the
volume of 700 grains measure marked on the scale. Each 1,000 grains
measure of this liquid now contains 14·29 grains of arsenious acid,
corresponding to 10 grains of chlorine, or 1/10 grain of chlorine
for every division or degree of the scale of the chlorimeter, for
which purpose a Mohr's burette of the above capacity may be used,
or a graduated tube of the form shown in Fig. 85 may be employed.

_Testing the Sample._--100 grains of the chloride of lime to
be tested are next dissolved in water, and poured into a tube
graduated up to 2,000 grains measure. The whole must be well shaken
in order to obtain a uniformly turbid solution, and half of it
(1,000 grains measure) transferred to a graduated chlorimeter,
which is, therefore, thus filled up to 0°, or the zero of the
scale, and contains exactly 50 grains of the chloride of lime
under examination, whilst each degree or division of the scale
contains only ½ grain. 1,000 grains measure of the arsenious acid
test-liquor are now poured into a glass beaker, and a few drops of
a solution of sulphate of indigo added, in order to impart a faint,
but distinct, blue colour to it; the glass is then to be shaken
so as to give a circular movement to the liquid, and whilst it is
whirling round the chloride of lime solution from the chlorimeter
is gradually and cautiously added until the blue tinge given to the
arsenious acid test-liquor is destroyed, care being taken to stir
the mixture well with a glass rod during the whole process, and to
stop as soon as the decoloration is complete. We will assume that
in order to destroy the blue colour of 1,000 grains measure of the
arsenious acid test-liquor 90 divisions or degrees of the chloride
of lime solution have been employed. These 90 divisions, therefore,
contained the 10 grains of chlorine required to destroy the colour
of the test solution; and since each division represents ½ grain
of chloride of lime, 45 grains of chloride of lime (10 grains of
chlorine) were present in the 90 divisions so employed, from which
the percentage strength may be ascertained:--

  For 45 : 10 :: 100 : 22·22.

The chloride of lime examined, therefore, contained 22¼ per
cent. (nearly) of chlorine. This method is extremely simple and
trustworthy when properly employed, but to ensure accuracy certain
precautions must be adopted. Instead of pouring the test liquor
into the solution of the sample (as in alkalimetry), the solution
of the sample must be poured into the test-liquor. If the contrary
plan were adopted the hydrochloric acid of the test-liquor would
liberate chlorine gas so fast that much would be lost, and the
result rendered incorrect. By pouring, on the contrary, the
chloride of lime solution into the arsenious acid solution the
chlorine is disengaged in small portions at a time, and meets with
an abundance of arsenious acid to react on. The mixture of chloride
of lime should also be employed turbid.

=Estimation of Alumina in Alum Cake, etc.=--Mr. Rowland Williams,
F.C.S., in a paper read before the Chemical Society in June,
1888, describes a method of estimating the alumina in alums,
alum cakes, and sulphate of alumina, by which he obtained more
accurate results than are obtained by the ordinary ammonia method
of estimation. After pointing out several objections to the method
of precipitating the alumina by ammonia, he proceeds:--"There
is another method for the estimation of alumina which is not so
well known as the above. This is by means of sodium thiosulphate.
Having had a very extensive and successful experience of this
process, I can recommend it with confidence. Considerable practice
is, however, necessary in order to secure good results, as
certain conditions must be carefully attended to, otherwise the
precipitation will be incomplete. The estimation is made in a
moderately dilute solution. In the case of alum cake and sulphate
of alumina I dissolve 400 grains in water, filter, dilute to 10,000
grains. I use 1,000 grains of this solution (equal to 40 grains of
the sample) for estimating the alumina. If any free acid is present
it is neutralised by a few drops of carbonate of soda solution,
and the whole diluted to about 8 ounces measure. A large quantity
of crystallized thiosulphate of soda is then added, and the liquid
boiled for at least half-an-hour, constantly replacing the water
lost by evaporation. By the end of that time all the alumina will
be precipitated in a finely-divided form, along with more or less
free sulphur. The precipitate is then filtered off and washed well
with boiling water. The filtration and washing take place very
rapidly, and may generally be accomplished in about twenty minutes,
this being a great saving of time in comparison with the long and
tedious washing by decantation, which is necessary in the case of
gelatinous alumina. Before filtration, it is advisable to add a
drop or two of carbonate of soda solution, lest the liquid should
have become slightly acid during boiling."



CHAPTER XX.

_USEFUL NOTES AND TABLES._

  Preparation of Lakes.--Brazil-wood Lake.--Cochineal Lake.--Lac
  Lake.--Madder Lake.--Orange Lake.--Yellow Lake.--Artificial
  Ultramarine.--Twaddell's Hydrometer.--Dalton's Table showing the
  proportion of Dry Soda in Leys of Different Densities.--Table
  of Strength of Caustic Soda Solutions at 59° F.--Table showing
  the Specific Gravity corresponding with the degrees of Baumé's
  Hydrometer.--Table of Boiling Points of Alkaline Leys.--Table
  showing the Quantity of Caustic Soda in Leys of Different
  Densities.--Table showing the Quantity of Bleaching Liquid at 6°
  Twaddell required to be added to Weaker Liquor to raise it to
  the given Strength.--Comparative French and English Thermometer
  Scales.--Weights and Measures of the Metrical System.--Table of
  French Weights and Measures.--List of Works relating to Paper
  Manufacture.


=Preparation of Lakes.=--These are prepared by either of the
following processes:--1. By adding a solution of alum, either
alone or partly saturated with carbonate of potassa, to a filtered
infusion or decoction of the colouring substance, and after
agitation precipitating the mixture with a solution of carbonate
of potash ("salt of tartar"). 2. By precipitating a decoction or
infusion of the colouring substance made with a weak alkaline
ley, by adding a solution of alum. 3. By agitating recently
precipitated alumina with a solution of the colouring matter,
prepared as before, until the liquid is nearly discoloured, or
the alumina acquires a sufficiently dark tint. The first method
is usually employed for aciduous solutions of colouring matter,
or for those whose tint is injured by alkalies; the second for
those that are brightened, or at least uninjured, by alkalies;
the third, those colouring matters that have a great affinity for
gelatinous alumina, and readily combine with it by mere agitation.
By attention to these general rules, lakes may be prepared from
almost all animal and vegetable colouring substances that yield
their colour to water, many of which will be found to possess great
beauty and permanence.

The precise process adapted to each particular substance may
be easily ascertained by taking a few drops of its infusion or
decoction, and observing the effects of alkalies and acids on the
colour.

The quantity of alum or of alumina employed should be nearly
sufficient to decolour the dye-liquor, and the quantity of
carbonate of potassa should be so proportioned to the alum as to
exactly precipitate the alumina, without leaving free or carbonated
alkali in the liquid. The first portion of the precipitate has
the deepest colour, and the shade gradually becomes paler as the
operation proceeds.

A beautiful "tone" of violet, red, and even purple may be
communicated to the colouring matter of cochineal by the addition
of perchloride of tin; the addition of arseniate of potassa
(neutral arsenical salt) in like manner gives shades which may
be sought for in vain with alum or alumina. After the lake is
precipitated it must be carefully collected, washed with cold
distilled water, or the purest rain-water, until it ceases to give
out colour.

=Brazil-wood Lake.=--1. Take of ground Brazil wood 1 lb., water
4 gallons; digest for 24 hours, then boil for 30 or 40 minutes,
and add of alum 1½ lb., dissolved in a little water; mix, decant,
strain, and add of solution of tin ½ lb.; again mix well and
filter; to the clear liquid add, cautiously, a solution of salt of
tartar or carbonate of soda, as long as a deep-coloured precipitate
forms, carefully avoiding excess. 2. Add washed and recently
precipitated alumina to a strong and filtered decoction of Brazil
wood. Inferior to the last.

=Cochineal Lake.=--1. Cochineal (in coarse powder) 1 oz.; water
and rectified spirit, of each, 2½ ozs.; digest for a week; filter
and precipitate the tincture with a few drops of solution of tin,
added every 2 hours, until the whole of the colouring matter is
thrown down; lastly, wash the precipitate in distilled water and
dry it; very fine. 2. Digest powdered cochineal in ammonia water
for a week, dilute the solution with a little water, and add the
liquid to a solution of alum, as long as a precipitate falls, which
is the lake. Equal to the last. 3. Coarsely powdered cochineal 1
lb., water 2 gallons; boil 1 hour, decant, strain, add a solution
of salt of tartar, 1 lb., and precipitate with a solution of alum.
By adding the alum first, and precipitating the lake with the
alkali, the colour will be slightly varied. All the above are sold
as carminated or Florence lake, to which they are often superior.


=Lac Lake.=--Boil fresh stick-lac in a solution of carbonate of
soda, filter the solution, precipitate with a solution of alum, and
proceed as before. A fine red.


=Madder Lake.=--1. Take of Dutch grappe or crop madder 2 oz.,
tie it in a cloth, beat it well in a pint of water in a stone
mortar, and repeat the process with fresh water (about 5 pints)
until it ceases to yield colour; next boil the mixed liquor in an
earthen vessel, pour it into a large basin, and add of alum 1 oz.,
previously dissolved in boiling water, 1 pint; stir well, and while
stirring, pour in gradually of a strong solution of carbonate of
potassa (salt of tartar) 1½ oz.: let the whole stand until cold,
then pour off the supernatant liquor, drain, agitate the residue
with boiling water, 1 quart (in separate portions), decant, drain,
and dry. Product, ½ oz. The Society of Arts voted their gold medal
to the author of the above formula. 2. Add a little solution
of acetate of lead to a decoction of madder, to throw down the
brown colouring matter, filter, add a solution of tin or alum,
precipitate with a solution of carbonate of soda or of potassa,
and otherwise proceed as before. 3. Ground madder, 2 lbs.; water,
1 gallon; macerate with agitation for 10 minutes, strain off the
water, and press the remainder quite dry; repeat the process a
second and a third time; then add to the mixed liquors, alum, ½
lb., dissolved in water, 3 quarts; and heat in a water-bath for
3 or 4 hours, adding water as it evaporates: next filter, first
through flannel, and when sufficiently cold, through paper; then
add a solution of carbonate of potassa as long as a precipitate
falls, which must be washed until the water comes off colourless,
and lastly, dry. If the alkali be added in 3 successive doses,
3 different lakes will be obtained, successively diminishing in
beauty.


=Orange Lake.=--Take of the best Spanish annotta 4 ozs.; pearlash,
¾ lb.; water, 1 gallon; boil it for half an hour, strain,
precipitate with alum, 1 lb., dissolved in water, 1 gallon,
observing not to add the latter solution when it ceases to produce
an effervescence or a precipitate. The addition of some solution of
tin turns this lake a lemon yellow; acids redden it.


=Yellow Lake.=--1. Boil French berries, quercitron bark, or
turmeric, 1 lb., and salt of tartar, 1 oz., in water, 1 gallon,
until reduced to one half; then strain the decoction and
precipitate with a solution of alum. 2. Boil 1 lb. of the dye-stuff
with alum, ½ lb.; water, 1 gallon, as before, and precipitate the
decoction with a solution of carbonate of potash.


=Artificial Ultramarine.=--This is obtained by several processes,
of which the following are examples:--1. Take kaolin, 37 parts;
sulphate of soda, 15; carbonate of soda, 22; sulphur, 18; and
charcoal, 8 parts; mix these intimately, and heat in large covered
crucibles for twenty-four to thirty hours. The resulting product
is then to be again heated in cast-iron boxes at a moderate
temperature, until the required tint is obtained; it is finally
pulverised, washed in a large quantity of water, and the floating
particles allowed to subside in a separate vessel; the deposited
colour is now collected and dried. 2. Expose to a low red heat,
in a covered crucible as long as fumes are given off, a mixture
composed of: kaolin, 2 parts; anhydrous carbonate of soda and
sulphur, of each 3 parts. Some persons use one-third less carbonate
of soda.


=Twaddell's Hydrometer=, which is much employed for ascertaining
the strength of soda and chloride of lime solutions, etc., is so
graduated and weighted that the 0 or zero mark is equal to 1,000,
or the specific gravity of distilled water at the temperature of
60° F., and each degree on the scale is equal to ·005; so that by
multiplying this number by the number of degrees marked on the
scale, and adding 1·, the real specific gravity is obtained. Thus
10° Twaddell indicates a specific gravity of 1050, or 1·05, and so
on.


=Imitation Manilla Pulp from Wood.=--Mr. George E. Marshall, of
Turner's Falls, Mass., patented a process some years back by which
wood, under the action of hot water, and under a heavy pressure,
acquires the characteristic colour of manilla. The wood, having
been cut as usual, is placed in a closed vessel or tank capable
of resisting high pressure, if necessary, of 450 lbs. to the
square inch, the material being closely packed. At the bottom of
this tank is an opening with a valve, through which the water,
previously heated to a point above boiling, and below 280°, is
forced by a hydraulic press to such an extent as to saturate and to
completely permeate the wood, and to soften and drive out of the
pores the gum, resins, and acids; and if the temperature is kept
sufficiently hot, it gives the pulp the desired colour belonging
to a finely-made manilla paper. This may be aided somewhat by the
introduction of a small quantity of some alkaline substance to
act on the acids. The water may be heated in a coil outside, and
forced into the tank by a hydraulic press. The water thus heated
and forced in leaves the wood or the pulp in the most desirable
condition for work and for colour. Pulp made from wood treated
below the boiling point will be white; but this process is said to
secure the desired manilla colour by raising the temperature to
240° or 250° for a light pulp, and as high as 280° for a dark pulp.
No pressure is required from the steam above three atmospheres, but
the press may give from 450 to 500 lbs. to the square inch, and
practice has shown that the greater the pressure the more speedy is
the operation on the wood.[36]


=Testing Ultramarines.=--The sample of ultramarine should
be examined as to its power of resisting the action of alum
solutions, which may readily be done by the method suggested by Mr.
Dunbar:--"Dissolve the same amount of each sample in water, and
mix in this water about ½ lb. of pulp. When thoroughly mixed, and
each lot of pulp is well and evenly coloured, add one glassful
of the ordinary mill alum liquor, either from pure alum, or
aluminous cake to each, losing no time over the operation. Stir
each well and continuously with a glass rod, and note the glasses
carefully as to the length of time each sample keeps its colour."
To ascertain the _staining power_, so called, of the ultramarine,
and at the same time the tone, or tint, which it will impart when
mixed with pulp, 25 grains of each sample should be mixed with 100
of kaolin or sulphate of lime (pearl hardening) and the several
mixtures then worked up into a paste with a little water by means
of a spatula, when the differences in the staining power of the
respective samples will at once become apparent if either be of
inferior quality. To make the test more complete, a like amount of
commercially pure ultramarine should be mixed with 100 grains of
kaolin for the purpose of comparison. In this way a ready judgment
may be formed as to the quality of the sample under examination.


=Strength of Paper.=--The comparative strength of samples of paper
may he determined by cutting strips an inch in width from each
sample, and suspending these from a rigid iron bar. Weights are
then cautiously attached to each until the sample breaks, when
the difference in the weights sustained by the respective samples
before the breaking point is reached will determine the comparative
strength of the samples tested. Mr. Parkinson, of St. George's
Road, Preston, furnishes a simple contrivance for determining the
breaking points of paper, and so comparing their value.



_TABLES._


I.--DALTON'S TABLE SHOWING THE PROPORTION OF DRY SODA IN LEYS OF
DIFFERENT DENSITIES.

   Specific      Dry Soda
  gravity of     per cent.    Boiling
   solution.    by weight.    points.

    1·85           63·6         600°
    1·72           53·8         400°
    1·63           46·6         300°
    1·56           41·2         280°
    1·50           36·8         265°
    1·47           34·0         255°
    1·44           31·0         248°
    1·40           29·0         242°
    1·36           26·0         235°
    1·32           23·0         228°
    1·29           19·0         224°
    1·23           16·0         220°
    1·18           13·0         217°
    1·12            9·0         214°
    1·06            4·7         213°


II.--TABLE OF STRENGTH OF CAUSTIC SODA SOLUTIONS AT 59° F. = 150°
C. (TÜNNERMAN).

  +--------------------------------------------------------------------+
  | Specific Gravity |  Degrees  | Per cent. of | Equivalent per cent. |
  |  (Water 1,000).  | Twaddell. |     Soda.    |   of 60 per cent.    |
  |                  |           |              |    Caustic Soda.     |
  |------------------+-----------+--------------+----------------------|
  |      1·0040      |    0·80   |     0·302    |         0·503        |
  |      1·0081      |    1·62   |     0·601    |         1·001        |
  |      1·0163      |    3·26   |     1·209    |         2·015        |
  |      1·0246      |    4·92   |     1·813    |         3·021        |
  |      1·0330      |    6·60   |     2·418    |         4·030        |
  |      1·0414      |    8·28   |     3·022    |         5·037        |
  |      1·0500      |   10·00   |     3·626    |         6·043        |
  |      1·0587      |   11·74   |     4·231    |         7·051        |
  |      1·0675      |   13·50   |     4·835    |         8·059        |
  |      1·0764      |   15·28   |     5·440    |         9·067        |
  |      1·0855      |   17·10   |     6·044    |        10·073        |
  |      1·0948      |   18·96   |     6·648    |        11·080        |
  |      1·1042      |   20·84   |     7·253    |        12·090        |
  |      1·1137      |   22·74   |     7·857    |        13·095        |
  |      1·1233      |   24·66   |     8·462    |        14·103        |
  |      1·1330      |   26·60   |     9·066    |        15·110        |
  |      1·1428      |   28·56   |     9·670    |        16·117        |
  |      1·1528      |   30·56   |    10·275    |        17·125        |
  |      1·1630      |   32·60   |    10·879    |        18·131        |
  |      1·1734      |   34·68   |    11·484    |        19·140        |
  |      1·1841      |   36·82   |    12·088    |        20·147        |
  |      1·1948      |   38·96   |    12·692    |        21·153        |
  |      1·2058      |   41·16   |    13·297    |        22·161        |
  |      1·2178      |   43·56   |    13·901    |        23·170        |
  |      1·2280      |   45·60   |    14·506    |        24·177        |
  |      1·2392      |   47·84   |    15·110    |        25·170        |
  +--------------------------------------------------------------------+


III.--TABLE SHOWING THE SPECIFIC GRAVITY CORRESPONDING WITH THE
DEGREES OF BAUMÉ'S HYDROMETER.

Liquids denser than Water.

  +-----------------------------------------------------------------+
  | Degrees. | Specific | Degrees. | Specific | Degrees. | Specific |
  |          | Gravity. |          | Gravity. |          | Gravity. |
  |----------+----------+----------+----------+----------+----------|
  |     0    |  1·0000  |    26    |  1·2063  |    52    |  1·5200  |
  |     1    |  1·0066  |    27    |  1·2160  |    53    |  1·5353  |
  |     2    |  1·0133  |    28    |  1·2258  |    54    |  1·5510  |
  |     3    |  1·0201  |    29    |  1·2358  |    55    |  1·5671  |
  |     4    |  1·0270  |    30    |  1·2459  |    56    |  1·5833  |
  |     5    |  1·0340  |    31    |  1·2562  |    57    |  1·6000  |
  |          |          |          |          |          |          |
  |     6    |  1·0411  |    32    |  1·2667  |    58    |  1·6170  |
  |     7    |  1·0483  |    33    |  1·2773  |    59    |  1·6344  |
  |     8    |  1·0556  |    34    |  1·2881  |    60    |  1·6522  |
  |     9    |  1·0630  |    35    |  1·2992  |    61    |  1·6705  |
  |    10    |  1·0704  |    36    |  1·3103  |    62    |  1·6889  |
  |          |          |          |          |          |          |
  |    11    |  1·0780  |    37    |  1·3217  |    63    |  1·7079  |
  |    12    |  1·0857  |    38    |  1·3333  |    64    |  1·7273  |
  |    13    |  1·0935  |    39    |  1·3451  |    65    |  1·7471  |
  |    14    |  1·1014  |    40    |  1·3571  |    66    |  1·7674  |
  |    15    |  1·1095  |    41    |  1·3694  |    67    |  1·7882  |
  |          |          |          |          |          |          |
  |    16    |  1·1176  |    42    |  1·3818  |    68    |  1·8095  |
  |    17    |  1·1259  |    43    |  1·3945  |    69    |  1·8313  |
  |    18    |  1·1343  |    44    |  1·4074  |    70    |  1·8537  |
  |    19    |  1·1428  |    45    |  1·4206  |    71    |  1·8765  |
  |    20    |  1·1515  |    46    |  1·4339  |    72    |  1·9000  |
  |          |          |          |          |          |          |
  |    21    |  1·1603  |    47    |  1·4476  |    73    |  1·9241  |
  |    22    |  1·1692  |    48    |  1·4615  |    74    |  1·9487  |
  |    23    |  1·1783  |    49    |  1·4758  |    75    |  1·9740  |
  |    24    |  1·1875  |    50    |  1·4902  |    76    |  2·0000  |
  |    25    |  1·1968  |    51    |  1·4951  |          |          |
  +-----------------------------------------------------------------+


IV.--TABLE OF BOILING POINTS OF ALKALINE LEYS.

  +---------------------------------------------------+
  | Alkaline | Specific | Percentage of |  Boils at   |
  |   Ley.   | Gravity. |    Alkali.    |   degrees   |
  |          |          |               | Fahrenheit. |
  |----------+----------+---------------+-------------|
  | Soda     |   1·18   |     13        |    217°     |
  | Potash   |   1·23   |     19·5      |    220      |
  | Soda     |   1·23   |     16        |    220      |
  | Potash   |   1·28   |     23·4      |    224      |
  | Soda     |   1·29   |     19        |    224      |
  | Soda     |   1·32   |     23        |    228      |
  | Potash   |   1·33   |     26·3      |    229      |
  | Soda     |   1·36   |     26        |    235      |
  | Soda     |   1·40   |     29        |    242      |
  | Potash   |   1·42   |     34·4      |    246      |
  | Soda     |   1·47   |     34        |    255      |
  | Potash   |   1·44   |     36·8      |    255      |
  | Soda     |   1·5    |     36·8      |    265      |
  | Potash   |   1·52   |     42·9      |    276      |
  | Potash   |   1·6    |     46·7      |    290      |
  | Soda     |   1·63   |     46·6      |    300      |
  | Potash   |   1·68   |     51·2      |    329      |
  +---------------------------------------------------+


V.--TABLE SHOWING THE QUANTITY OF CAUSTIC SODA IN LEYS OF DIFFERENT
DENSITIES (WATER 1,000).

  +---------------------------------------------+
  | Specific |   Soda    | Specific |   Soda    |
  | gravity. | per cent. | gravity. | per cent. |
  |----------+-----------|----------+-----------|
  |   1·00   |    0·00   |   1·22   |   20·66   |
  |   1·02   |    2·07   |   1·24   |   22·58   |
  |   1·04   |    4·02   |   1·26   |   24·47   |
  |   1·06   |    5·89   |   1·28   |   26·33   |
  |   1·08   |    7·69   |   1·30   |   28·16   |
  |   1·10   |    9·43   |   1·32   |   29·96   |
  |   1·12   |   11·10   |   1·34   |   31·67   |
  |   1·14   |   12·81   |   1·35   |   32·40   |
  |   1·16   |   14·73   |   1·36   |   33·08   |
  |   1·18   |   16·73   |   1·38   |   34·41   |
  |   1·20   |   18·71   |          |           |
  +---------------------------------------------+


VI.--TABLE SHOWING THE QUANTITY OF BLEACHING LIQUID AT 6° TWADDELL
(SPECIFIC GRAVITY 1·030) REQUIRED TO BE ADDED TO WEAKER LIQUOR TO
RAISE IT TO THE GIVEN STRENGTHS.

  +----------------------------------------------------------+
  |   Strength of    | Required  |   Proportions Required.   |
  | Sample in 1/12°. | Strength. |---------------------------|
  |                  |           |Given Sample.|Liquor at 6°.|
  |------------------+-----------+-------------+-------------|
  |                  |           |   parts.    |    part.    |
  |      Water       |   8/12°   |     8       |      1      |
  |        1         |    "      |     9¼      |      1      |
  |        2         |    "      |    11       |      1      |
  |        3         |    "      |    13½      |      1      |
  |        4         |    "      |    17       |      1      |
  |        5         |    "      |    23       |      1      |
  |        6         |    "      |    35       |      1      |
  |        7         |    "      |    71       |      1      |
  |      Water       |   6/12°   |    11       |      1      |
  |        1         |    "      |    13½      |      1      |
  |        2         |    "      |    17       |      1      |
  |        3         |    "      |    23       |      1      |
  |        4         |    "      |    35       |      1      |
  |        5         |    "      |    71       |      1      |
  |      Water       |   4/12°   |    17       |      1      |
  |        1         |    "      |    23       |      1      |
  |        2         |    "      |    35       |      1      |
  |        3         |    "      |    71       |      1      |
  |      Water       |   3/12°   |    23       |      1      |
  |        1         |    "      |    35       |      1      |
  |        2         |    "      |    71       |      1      |
  +----------------------------------------------------------+


VII.--COMPARATIVE FRENCH AND ENGLISH THERMOMETER SCALES.

  French or Centigrade.               English or Fahrenheit.

     0  Cent. or C.          equals     32  Fahr. or F.
     5      "                  "        41     "
    10      "                  "        50     "
    15      "                  "        59     "
    20      "                  "        68     "
    25      "                  "        77     "
    30      "                  "        86     "
    35      "                  "        95     "
    40      "                  "       104     "
    45      "                  "       113     "
    50      "                  "       122     "
    55      "                  "       131     "
    60      "                  "       140     "
    65      "                  "       149     "
    70      "                  "       158     "
    75      "                  "       167     "
    80      "                  "       176     "
    85      "                  "       185     "
    90      "                  "       194     "
    95      "                  "       203     "
   100      "  (Water boils)   "       212     "  (Water boils)
   200      "                  "       392     "
   300      "                  "       572     "
   356      "  (Mercury boils) "       662     "  (Mercury boils)


VIII.--WEIGHTS AND MEASURES OF THE METRICAL SYSTEM.

(From the British Pharmacopœia.)

WEIGHTS.

  1 Milligramme = the thousandth part of one gramme, or   0·001 gramme.
  1 Centigramme = the hundredth        "        "         0·01     "
  1 Décigramme  = the tenth            "        "         0·1      "
  1 Gramme      = weight of a cubic centimètre
                  of water at 4° C.                       1·0      "
  1 Décagramme  = ten grammes                            10·0      "
  1 Hectogramme = one hundred grammes                   100·0      "
  1 Kilogramme  = one thousand grammes                1,000·0      "

MEASURES OF CAPACITY.

  1 Millilitre =     1 cubic centimètre,
                                   or the measure of 1 gramme of water.
  1 Centilitre =    10       "           "          10      "
  1 Décilitre  =   100       "           "         100      "
  1 Litre      = 1,000       "           "       1,000      "

MEASURES OF LENGTH.

  1 Millimètre = the thousandth part of one mètre, or 0·001 mètre.
  1 Centimètre = the hundredth       "      "         0·01    "
  1 Décimètre  = the tenth           "      "         0·1     "
  1 Mètre      = the ten-millionth part of a quarter of the meridian
                   of the earth.


IX.--TABLE OF FRENCH WEIGHTS AND MEASURES.

  Kilogramme, 1,000 grammes, equals 2 lbs. 3¾ ozs. nearly.
  Gramme (the unit) equals 15·432 grains.

FRENCH MEASURE OF VOLUME.

  1 Litre (the unit) equals 34 fluid ozs. nearly.

LONG MEASURE.

  Mètre (the unit)                equals  39·371  inches.
  Décimètre (10th of a mètre)       "     3·9371    "
  Centimètre (100th of a mètre)     "     0·3937    "
  Millimètre (1,000th of a mètre)   "     0·0393    "



LIST OF WORKS RELATING TO PAPER MANUFACTURE.


"Practical Remarks on Modern Paper." J. Murray. Edinburgh, 1829.

"Manuel du Fabricant des Papiers." L. S. Le Normand. Paris, 1834.

"L'Industrie de la Papetrie." G. Planche. Paris, 1853.

"Die Fabrikation des Papiers." L. Müller. Berlin, 1855.

"Manufacture of Paper and Boards." A. Proteaux. Philadelphia, 1866.

"Manufacture of Paper." C. Hofmann. Philadelphia, 1873.

"Pflanzenfasir." Hugo Müller. Leipzig, 1873.

"Bamboo Considered as a Paper-making Material." London, 1875.

"Etudes sur les Fibres Végétales." Vétillart. Paris, 1876.

"Technology of the Paper Trade" (Cantor Lectures). Arnot. Journal
Society of Arts, 1877.

"The Practical Paper-maker." J. Dunbar. London, 1881.

"Forestry and Forest Products." Edinburgh, 1884.

"A Treatise on Paper." R. Parkinson. Preston, 1886.

"Manufacture of Paper." C. T. Davis. Philadelphia, 1887.

"Manufacture of Paper." Tomlinson.

"Text Book of Paper-making." C. F. Cross and E. J. Bevan.

Articles on paper-making will also be found in the following
encyclopædias, journals, etc:--

"Encyclopædia Britannica," vol. xvii.; "Encyclopædia
Metropolitana," 1845; "Tomlinson's Cyclopædia;" "New American
Cyclopædia;" "British Manufacturing Industries;" "English
Cyclopædia;" "Encyclopædia Americana;" "Penny Cyclopædia;" _Paper
Makers' Monthly Journal_; _Paper Makers' Circular_; _Paper Trade
Journal_; _American Paper Trade Journal_.



INDEX.


  Acetic acid, 64, 98

  Acid, arsenious, process, 231
    or bisulphite processes, objections to, 74
    boracic, 46
    carbonic, 97
    fluo-silicic, 175
    hydrochloric, 55, 232
    hypochlorous, 98
    nitric, 66
    nitrous, 66
    nitro-hydrochloric, 64
    oxalic, 98
    processes, McDougall's boiler for, 72
    sulphuric, 47, 99
      anhydrous, 225
    sulphurous, 55, 175
    test, 224
    test, preparation of, 225
    treatment of wood, 64

  Acids, action of, on cellulose, 2

  Acicular fibres, 3

  Action of acids on cellulose, 2

  Adamsonia, 85

  Adamson's process, 77

  African esparto, 47

  Agalite, 115

  Agar-agar, 178

  Agave Americana, 8

  Alexandria rags, 21

  Algerian esparto, 47

  Alkali, caustic, 48
    testing, 224

  Alkalimeter, Mohr's, 223

  Alkalimeters, 222

  Alkalimetry, 221

  Alkaline leys, boiling points of, 243

  Alkalis, sampling, 227

  Alum, 116

  Alum, bleach liquor, 100
    cake, estimation of alumina in, 233
    concentrated, 119
    crystallised, 119
    liquor, 240
    pearl, 119
    porous, 167

  Alumina, estimation of, in alum, &c., 233
    sulphate of, 100

  Aluminium, chloride of, 100
    hypochlorite of, 100

  Aluminous cake, 119

  American combinations for colouring, 167
    method of sizing, 123
    ochre, 167
    refining engines, Mr. Wyatt on, 103
    system of soda recovery, 218
    wood pulp, 60

  Ammonia, 233

  Ammoniacal water, 6

  Andreoli's electrolytic bleaching process, 96

  Anhydrous soda, 225
    sulphuric acid, 225

  Aniline blues, 166
    reds, 166
    sulphate of, 8
    triethyl rose, 98

  Animal size, preparation of, 120, 122
    sized papers, 123
    or tub-sizing, 122

  Annotta, Spanish, 238

  Antichlor, 109

  Antique paper, 157

  Apparatus, disintegrating, 72
    evaporating, 205

  Aqua regia, 66

  Arnot, Mr., on beating-engines, 102
    on finishing, 160

  Arnot's method of alkali testing, 229

  Artificial flowers, colouring paper for, 168
    ultramarine, 238

  Arsenious acid process, 231

  Asbestos, 73, 115

  Ash, black, 219

  Aussedat's process, 63

  Azure blue, 170


  Back-water pump, Bertrams', 195

  Bagging, old, 10

  Balsam, Canada, 179

  Baltic rags, 21

  Bamboo cane, 10, 18

  Bambusa vulgaris, 18

  Banana fibre, 10

  Bank-notes, water-marking, 147

  Baobab, 85

  Bark fibres, 6
    oak, 166
    paper mulberry, 10

  Barre and Blondel's process, 66

  Bast bagging, 10

  Baumé's hydrometer, 242

  Beakers, 222, 224

  Beater, 37
    Jordan, 103, 104
    Kingsland, 104

  Beating, 101
    Dunbar's observations on, 102
    engine, 103
      Bertrams', 105
      Forbes', 105
      Umpherston's, 105
    engines, Arnot on, 102
    operations of, 107
    or refining, 101

  Belgian rags, 20

  Bentley and Jackson's boiler, 80
    cooling and damping rolls, 189
    drum-washer, 185
    dry felt self-acting regulator, 186
    glazing calender, 155
    rag-cutter, 24
      engine, 38
    single-cylinder machine, 153
    web-ripping machine, 198

  Benzine, 5, 77

  Berlin blue, 168

  Bertrams' back-water pump, 195
    beating-engine, 105
    conical pulp-saver, 144
    damping-rolls, 155
    edge-runner, 82
    esparto-cleaner, 40
    large paper machine, 134
    rag boiler, 29
      cutting-machine, 23
      engine, 37
    revolving strainer and knotter, 137
    revolving knife-cutter, 162
    reeling machine, 197
    single-sheet cutter, 162
    web-glazing calender, 196
    willowing and dusting machine, 26

  Beetroot refuse, 10

  Beyrout rags, 21

  Bichromate of potassa, 165

  Binders' clippings, 10

  Birch, 60

  Bisulphite of lime, 71
      magnesium, 70
    process, Blitz's, 72
      Francke's, 68
      Graham's, 73
      Mitscherlich's, 71
      objections to, 74

  Black ash, 219
    calicoes, 20
    cotton, 20
    Frankfort, 171
    lamp, 166

  Blacks, 20

  Bleach, 93
    liquor, alum, 100
      Wilson's, 100
      zinc, 99
    mixer, 92
    pump, Donkin's, 193

  Bleaching, 89
    agent, 90
    with chloride of lime, 92
      chlorine gas, Glaser's process, 93
    C. Watt, jun.'s, electrolytic process, 94
    electrolytic, Andreoli's process, 96
    Hermite's process, 96
    esparto, 50
    liquid, table showing quantity to be used, 244
    liquor, 50, 91
      preparation of, 92

  Bleaching liquors, 3
    Lunge's process of, 98
    new method of, 100
    operations, 89
    powder, 92
      estimation of chlorine in, 230
      Fresenius' method, 231
      Gay-Lussac's method, 231

  Bleaching, sour, 91
    Thompson's process, 97
    Young's method, 100

  Blending, 112

  Blitz's process, 72

  Blotting-papers, 21, 181

  Blue, 166
    azure, 170
    Berlin, 168
    Bremen, 170
    cottons, 20
    dark, 170
    indigo, 166
    linens, 20
    mineral, 171
    pale, 170
    paper, 19
    Paris, 169
    Prussian, 165
    rags, 19
    smalts, 165

  Blues, 20
    aniline, 166

  Boiler, Bentley and Jackson's, 80
    Roeckner's, 45

  Boiling, American, 60
    esparto, 41
    rags, 29
    straw, 81
    waste paper, 86

  Boracic acid, 46

  Borax, 169

  Boxes, suction, 148

  Brazil wood, 166
    lake, 236

  Breaking half-stuff, 39
    points of paper, method of determining, 240

  Breaking and washing, 34

  Breast-roll, 149

  Bremen blue, 170

  "Broke" paper, 85

  Bromine, 6
    water, 6

  Broom, 10

  Broussonetia papyrifera, 18

  Brown, 167

  brown, dark, 170
    reddish, 172

  Bucking-keir, 88

  Buckwheat straw, 10

  Buff envelope, 167

  Bunsen burner, 225

  Burettes, 222


  Calcined soda, 93

  Calciner, 206

  Calcium, acetate of, 98
    chloride of, 109, 230
    hypochlorite of, 3
    salts, 99

  Calender, glazing, 154

  Calendering, 154
    super, Mr. Wyatt on, 158

  Calicoes, black, 20

  Canada balsam, 179

  Cane, bamboo, 10
    rattan, 10

  Caoutchouc, 73

  Carbonate of lime, 119
    magnesia, 46
    potassa, 235, 236
    soda, 31

  Carbonell's esparto process, 46

  Carbonic acid, 97

  Carbonisation, 75

  Cardboard, 182
    with two faces by ordinary machinery, 182
    work, 179

  Carminated lake, 237

  Carrageen moss, 178

  Carrying tubes, 143

  Castile soap, 121

  Caustic alkali, 48
    potash, 3, 7
    soda, 31
      ley, 31
      table showing quantities of, in leys of different densities, 243

  Causticising soda, 32, 205
    tanks, 218

  Cellulose, 1
    action of acids on, 2
    determination of, 5
    of flax, 4
    physical characteristics of, 3
    white, 76

  Chemical combination, 224
    processes, 55
    wood pulp, 54

  Chilled-iron glazing-rolls, 156

  China clay, 114
    grass, 10

  Chloride of aluminium, 100
    calcium, 101, 230
    lime, 47, 230
      bleaching with, 92
      testing samples of, 232
    magnesium, 96
    potassium, 95
    sodium, 95, 109
    zinc, 99

  Chlorimeter, 232

  Chlorimetry, 231

  Chlorine, 2, 90, 232
    gas, bleaching with, 93
    in bleaching powder, estimation of, 230
    test for, 110

  Chrome, lemon, 170
    orange, 166
    yellow, 166

  Cinnabar, 171

  Citrate of tin, 169

  Clarifier, Roeckner's, 199

  Clay, China, 114

  Clogging, 116

  "Close" paper, 112

  Cobalt, oxide of, 165

  Cochineal, 121, 166
    lake, 236

  Colcothar, 170

  Coloured cotton, 20
    papers, 165

  Colouring, 121
    American combinations for, 167
    materials, mixing, with pulp, 168
    matters used in paper making, 166
    paper for artificial flowers, 168

  Commercial sodas, examination of, 221

  Comparative cost of animal and engine sizing, estimate of, 128
    French and English thermometer scales, 244

  Composition for waterproof paper, 177

  Concentrated alum, 119

  Conical pulp-saver, 144

  Cooling and damping rolls, Bentley and Jackson's, 189

  Copal, white, 179

  Copper, green, 170
    hydrated oxide of, 175
    sulphate, 146

  Copperas, 165

  Copying-paper, 120

  Corchorus capsularis, 4

  Cork, 180
    paper, 180

  Cost of animal and engine sizing, comparative estimate of, 128

  Cotton fibre, 3
    filaments of, 7
    pieces, 20
    rags, 10
    seed waste, 10
      oil soap, 121
    superfine whites, 20
    waste, 10
    wool, 10

  Cottons, blue, 20
    outshot, 20
    unbleached, 20

  Coucher, 130

  Couch-rolls, 149

  Coupier and Mellier's process, 80, 84

  Crop madder, 237

  Crystallised alum, 119

  Cupro-ammonium, 2, 174
    Wright's process of preparing, 175

  Cutting, 22, 161
    machine, 23
      Verny's, 187

  Cutter, single-sheet, 162

  Cutters, 22

  Cylinder, drying, 185
    machine, single, 152
    washing, 193

  Cylinders, drying, 151


  Dalton's table showing proportion of dry soda in leys of different
        densities, 241

  Damping-rolls, Bertrams', 155

  Dandy-roll, 144

  Deckle, 130
    frame, 143
    strap, 143

  De la Rue's improvements in water-marks, 147

  Determination of cellulose, 5

  Determining the real value or percentage of commercial sodas,
        chloride of lime, &c., 221

  Devil, Donkin's, 27

  Dextrin, 2

  Diana's process for making paper or cardboard with two faces by
        ordinary machinery, 182

  Digester, 65

  Disinfecting machine, 12

  Disintegrating apparatus, 79

  Doctor, the, 150

  Donkin's bleach-mixer, 92
      pump, 193
    glazing machine, 157
      press, 157
    plate-planing machine, 191
    rag boiler, 30
      dusting machine, 26
    washing cylinder for rag-engine, 193

  Double crown, 164
    demy, 164
    royal, 164

  Double-sized paper, 126

  Drab, 167

  Drainers, 39

  Draining, 39

  Dr. Mitscherlich's process, 71

  Drum-washer, 34
    Bentley and Jackson's, 185

  Dry-felt regulator, self-acting, 186

  Drying cylinder, 185
    cylinders, 151

  Dunbar's method of treating esparto, 48
    observations on beating, 102

  Duster, 26

  Dusting, 26

  Dutch grappe madder, 237

  Dyers' wood waste, 10


  Edge-runner, Bertrams', 82

  Ekman's process, 70

  Elastic fibres, 3
    packing, 72

  Electrolytic bleaching process, Andreoli's, 96
    Hermite's, 96
    C. Watt's, 94

  Electrotypes for water-marking, 146

  Engine, beating, 103
      Bertrams', 105
      Forbes', 105
      Umpherston's, 105
    Marshall's perfecting, 201
    size, French method of preparing, 120
    sizing, 115

  Engines, beating, Mr. Arnot on, 102
    refining, American, Mr. Wyatt on, 103

  English green, 172
    pink, 172

  Envelope, buff, 167
    orange-red gold, 167
    yellow gold, 167

  Eosine, 166

  Equivalents, chemical, 224

  Esparto, African, 47
    Algerian, 47
    bleaching, 50
    boiler, Sinclair's, 42, 43
    boiling, 41
    cleaner, Bertrams', 40
    Dunbar's treatment of, 48
    fibre, 4
    Gabes, 47
    grass, 10, 16
    Mallary's process for, 46
    Oran, 47
    picking, 40
    preliminary treatment of, 40
    Carbonell's process for, 46
    Sfax, 47
    Spanish, 47
    Susa, 47
    Tripoli, 47
    washing boiled, 49
    willowing, 41
    Young's process for boiling, 50

  Estimation of alumina in alum cake, &c., 233
    of chlorine in bleaching powder, 230
    of commercial sodas, 221

  Eucalyptus, oil of, 178

  Evaporating apparatus, 205

  Evaporator, esparto, 206
    Porion's, 208
    Roeckner's, 206
    Yaryan's, 208

  Evaporators, American, 61, 208

  Examination of commercial sodas, 221


  Feebly-ribbed, or smooth fibres, 5

  Felt, 72, 101

  Felting, 131

  Fern leaves, 10

  Ferrocyanide of potassium, 165

  Fibre, banana, 10
    cotton, 3
    esparto, 4
    flax, 7
    hemp, 8
    jute, 4, 8
    linen, 4
    Manilla, 4
    sulphite, and resin, 76
    yellow pine, 4

  Fibres, acicular, 3
    bark, 6
    elastic, 3
    round-ribbed, 5
    smooth, or feebly-ribbed, 5
    spiral, 8
    straw, 4
    various, treatment of, 80
    vegetable, micrographic examination of, 5
    vegetable, recognition of, by the microscope, 6

  Fibrous waste, 11

  Finished paper, packing the, 163

  Finishing, 157
    Arnot on, 160
    house, 163
    and sizing, 132

  First press-roll, 150

  Flask, 227

  Flax, cellulose of, 4
    fibre, or linen, 7
    New Zealand, 8, 10
    tow, 11
    waste, 10

  Flocks, 73

  Florence lake, 237

  Foolscap, 164

  Forbes' beating-engine, 105

  Foreign rags, 20

  Fourdrinier machine, 133

  Francke's bisulphite process, 68

  Frankfort black, 169

  French and English thermometer scales, comparative, 244
    measure of volume, 245
    rags, 20
    weights and measures, table of, 245

  Fresenius' method of estimating bleaching powder, 231

  Friction-glazing, 157

  Fridet and Matussière's process, 66

  Furnace, incinerating, 208

  Fustians, 20

  Fustic, 169


  Gabes esparto, 47

  Gaine's process for making parchment paper, 182

  Gamboge, 169

  Gas, chlorine, bleaching with, 93
    receiver, 65

  Gay-Lussac's method of estimating bleaching powder, 231

  German rags, 21

  Glaser's process for bleaching with chlorine gas, 93

  Glauber's salt, 109

  Glazing calender, 154
    press, Donkin's, 157
    rolls, chilled-iron, 156
    web, 154

  Glucose, 2

  Glue pieces, 122
    stock, 124

  Glycerin, 120

  Graham's process, 73

  Grass, China, 10
    esparto, 10, 16
    sea, 11

  Green, copper, 170
    English, 172
    pale, 170
    Schweinfurth, 171

  Grey linens, 20

  Ground madder, 237
    wood pulp, 85

  Guillotine rag-cutter, 24

  Gum arabic, 169
    sandarac, 179
    tragacanth, 168

  Gunny, 20
    bags, 10

  Gutta-percha, 147


  Half jute and linen, 20
    stuff, 39, 101
      breaking, 39

  Hemp fibre, 8
    Manilla, 4, 10
    sizal, 8
    tarred, 20
    waste, 10
    white, 20

  Hermite's electrolytic bleaching process, 96

  High-pressure boiler, 63

  Hollander, or rag-engine, 34, 129

  Home rags, 20

  Hop-bines, 10

  Hydrate of soda, 225

  Hydrated oxide of copper, 175

  Hydro-cellulose, 1

  Hydrochloric acid, 55, 232

  Hydro-extractor, 94

  Hydrometer, Baumé's, 242
    Twaddell's, 238

  Hypochlorite of aluminium, 100
    calcium, 3
    lime, 92, 98, 230
    soda, 8
    sodium, 96

  Hypochlorous acid, 98

  Hyposulphite of soda, 110


  Iodide of potassium, 111

  Imitation Manilla pulp from wood, 239

  Imperial, 164

  Incinerating furnace, 208

  Indiarubber, vulcanised, 223

  Indigo, 98, 166
    sulphate of, 232

  Ink, lithographic, 180

  Introduction of wood pulp, 17

  Irish moss, 178

  Iron, oxide of, 34

  Iron, pernitrate of, 165
    sulphate of, 170

  Isinglass, 179


  Japanese paper, new, 180

  Jordan's beating engine, 103, 104

  Jouglet's process for waterproof paper, 177

  Jute fibre, 4, 8
    Manilla, &c., 84
    spinners' waste, 20
    waste, 10, 20


  Kaolin, 114, 182

  Keegan's process, 59

  Killing the colour, 121

  Kingsland beating-engine, 104

  Knife, revolving, 161

  Knotter and strainer, revolving, 137

  Kollergang, or edge-runner, 82


  Lac lake, 237

  Laid paper, 130

  Lake, Brazil-wood, 236
    carminated, 237
    cochineal, 236
    Florence, 237
    lac, 237
    madder, 237
    orange, 238
    scarlet, 171

  Lakes, preparation of, 235

  Lamp-black, 166, 169

  Leaching, 218
    tanks, 218

  Lead, nitrate of, 167
    white, 171

  Leather waste, 11

  Leghorn rags, 21

  Lemon chrome, 170

  Leys, alkaline, boiling point of, 243
    of different densities, table showing quantities of caustic soda
          in, 243

  Lime, bisulphite of, 71
    carbonate of, 119
    chloride of, 23, 47, 110
      bleaching with, 92
      testing, 232
    hypochlorite of, 92, 98, 230
    milk of, 33, 72, 110
    sulphate of, 100

  Limed skins, 122

  Linen, 4
    fibre, 4
    or flax fibre, 7
    pieces, 20
    rags, 10
    waste, 10

  Linens, blue, 20
    extra fine, 20
    grey, 20
    strong, 20
    white, 20

  Liquor, bleaching, preparation of, 92

  Liquors, bleaching, 3
    spent, recovery of soda from, 218

  Lithographic ink, 180
    paper, 180

  Litmus paper, 183

  Lixiviation, 75

  Loading, 114

  Logwood, 166

  Long measure, French, 246

  Lunge's bleaching process, 9


  Machine, Bentley and Jackson's perfecting, 201
    web-ripping, 198
    Bertrams' large paper, 13
      rag-cutting, 23
      reeling, 197
      web-glazing, 196
      willowing and dusting, 26
    disinfecting, 12
    Donkin's plate-planing, 191
      rag-dusting, 23
    Fourdrinier, 133
    rag-cutting, 23
    roll-bar planing, 191
    single-cylinder, 152
      web-winding, 188
    sizing, 126
    Verny's paper-cutting, 187
    wire and its accessories, 142
    Yankee, 152

  Machinery, making paper by, 133
    used in paper-making, 184

  Machines, wet, 57

  Madder, Dutch, 237
    ground, 237
    lake, 237

  Magnesia, carbonate of, 46
    sulphate of, 46

  Magnesian limestone, 69

  Magnesite, 46, 70

  Magnesium, bisulphite of, 70
    chloride of, 96

  Maize husks and stems, 10

  Making the paper, 130
    paper or cardboard with two faces by ordinary machinery, 182
    paper by hand, 129
      machinery, 133

  Mallary's process for esparto, 46

  Manganese, peroxide of, 94

  Manilla fibre, 4
    hemp, 4, 10
    jute, &c., 84
    paper, 85

  Manilla, imitation, from wood pulp, 239

  Manning winder, 159

  Maori-prepared phormium, 8

  Materials, raw, 10
    used in paper-making, 9

  Marking, water, 146

  Marshall's perfecting engine, 201

  McDougall's boiler for acid processes, 72

  Mechanical processes, 78
    wood pulp, 113
      Voelter's process of preparing, 78

  Megass, or cane trash, 10

  Mellier's process, 84

  Method of sizing, American, 123

  Metrical system, weights and measures of, 245

  Micrographic examination of vegetable fibres, 5

  Microscope, recognition of vegetable fibres by, 6

  Midfeather, 35

  Milk of lime, 33, 72, 110

  Millboard, 175, 182

  Mincing the fibre, 102

  Mineral blue, 171
    orange, 166

  Miscellaneous papers, 174

  Mixed fines, 20
    prints, 20

  Mixing colouring materials with pulp, 168

  Mohr's alkalimeter, 223

  Molasses, 180

  Morfit's process for toughening paper, 178

  Morocco papers, stains for, 171

  Mucilage, 94

  Mustard oil, 46
    stems, 10


  Nascent chlorine, 96

  Netting, old, 11

  New Japanese paper, 180
    method of bleaching, 100

  New rags, 20

  New Zealand flax, 8, 10

  Nitric acid, 66

  Nitro-hydrochloric acid, 64

  Nitrous acid, 66

  Notes and tables, 235

  Nutgalls, 166

  Nuttall's rag-cutter, 24


  Oak-bark, 166

  Oakum, 11

  Objections to the acid or bisulphite process, 74

  Ochre, American, 167
    yellow, 165, 166

  Oil, boiled, 179
    cotton-seed, soap, 121
    of eucalyptus, 178
    linseed, 179
    mustard, 46
    resin, 178
    of turpentine, 179
    of vitriol, 100

  Oiled paper, 180

  Old bagging, 10
    bast bagging, 10
    canvas, 10
    netting, 11
    rope, 10
    style, 157

  Operation of beating, 107

  Oran esparto, 47

  Orange chrome, 166
    lake, 238
    mineral, 166
    red gold envelope, 167
    yellow, 171

  Organic acid, 99

  Outshot cottons, 20

  Outshots (whites), 20

  Overhaulers, 22

  Oxalic acid, 98

  Oxide of cobalt, 165
    iron, 34
    zinc, 99


  Packing the finished paper, 163

  Pale blue, 170

  Panels, millboard, 175

  Pasteboard, 179

  Paper, animal-sized, 123
    antique, 157
    blotting, 21, 181
    blue, 19
    breaking points of, method of determining, 240
    "broke," 85
    or cardboard with two faces made by ordinary machinery, 182
    colouring, for artificial flowers, 168
    copying, 120
    cork, 180
    cutting machine, Verny's, 187
    double sized, 126
    hand-made, 129
    new Japanese, 180
    machine, Bertrams' large, 134
      Fourdrinier's, 133
      Yankee, 152
    making by hand, 129
      by machinery, 133
      machinery used in, 184
      materials used in, 9
    manilla, 85
    imitation manilla, from wood, 239
    Morfit's process for toughening, 178
    mulberry, 18
    bark, 10
    oiled, 180
    old style, 157
    parchment, 181
    shavings, 58
    sizes of, 164
    strength of, 240
      Parkinson's contrivance for determining, 240
    toned, 165
    toughening, 178
    tracing, 179
    transparent, 179
    turmeric, 183
    varnished, 179
    vegeto-mineral, 115
    waste, 85
      boiling, 86
      Ryan's process for treating, 87
    water-marked, 130
    waterproof, 174
      Jouglet's process, 177
    for windows, 181
    coloured, 165
    miscellaneous, 174
    Morocco, stains for, 171
    printing, 164
    satin, stains for, 172
    test, 183
    wrapping, 178
    writing, 164

  Parchment liquor, 171
    paper, 181
    shavings, 171

  Paris blue, 169

  Parker and Blackman's disinfecting machine, 12

  Parting, 131

  Partington's process, 71

  Pearl alum, 119

  Pearlash, 238

  Pearl hardening, 114

  Peat, 10

  Pectin, 6

  Pectose, 6

  Perchloride of tin, 236

  Perfecting engine, Marshall's, 201

  Pernitrate of iron, 165

  Peroxide of manganese, 94

  Petroleum, 178

  Phormium tenax, 8

  Physical characteristics of cellulose, 3

  Picking esparto, 40

  Pictet and Brélaz's process, 64

  Pieces, cotton, 20
    linen, 20

  Pink, 166
    English, 172

  Plate-glazing, 157
      calender, reversing, 191
    planing machine, 190

  Poplar, 10, 60

  Porion's evaporator, 208

  Porous alum, 167

  Potash, 74
    carbonate of, 235
    caustic, 3, 7
    yellow prussiate of, 165

  Potassa, carbonate of, 235

  Potassium, chloride of, 95
    iodide of, 111
    ferrocyanide of, 165

  Potcher, 37

  Poucher, 39

  Poumarède and Figuier's process for parchment paper, 181

  Preliminary operations, 19
    treatment of esparto, 40

  Preparation of animal size, 122
    bleaching liquor, 92
    lakes, 235
    test acid, 225

  Press, glazing, Donkin's, 157

  Press-rolls, 150

  Presse-pâte, 51

  Printing-paper, 103
    papers, 164

  Prints, light, 20
    mixed, 20

  Process, Adamson's, 77
    American wood pulp, 60
    Andreoli's electrolytic bleaching, 96
    arsenious acid, 231
    Aussedat's, 63
    Barre and Blondel's, 66
    Blitz's, 72
    Carbonell's esparto, 46
    Coupier and Mellier's, 80
    C. Watt's electrolytic bleaching, 94
    Diana's, for making paper with two faces by ordinary machinery, 182
    Dr. Mitscherlich's, 71
    Eckman's, 70
    Francke's bisulphite, 68
    Fridet and Matussière's, 66
    Gaine's, for making parchment paper, 182
    Graham's, 73
    Hermite's electrolytic bleaching, 96
    Jouglet's, for preparing waterproof paper, 177
    Keegan's, 59
    Lunge's bleaching, 98
    Mallary's esparto, 46
    Mellier's, 84
    Morfit's, 178
    Partington's, 71
    Pictet and Brélaz's, 64
    Poumarède and Figuier's, 181
    retting, 129
    Ritter and Kellner's, 71
    Ryan's, 87
    Scoffern and Tidcombe's, 174
    Sinclair's, 58
    Thompson's, 97
    Thune's, 79
    Voelter's, 78
    Watt and Burgess's, 55
    Wright's, 175
    Young's, 50
    Young and Pettigrew's, 66

  Processes, acid or bisulphite, objections to, 74
    McDougall's boiler for, 72
    chemical, 55
    mechanical, 78
    sulphide, 77
    sulphite, 68

  Prussian blue, 165

  Prussiate of potash, 165

  Pulp, ground wood, 85
    long-fibred, 111
    mechanical wood, 113
    mixing colouring matter with, 168
    rag, 72

  Pulp saver, 143
      conical, 144
    strainers, 137
      Bertrams' revolving, 137
      Roeckner's, 140

  Pulp, sulphite, 68, 160
    wood, American, 60
      first introduced by Mr. C. Watt, 17
      imitation Manilla from, 239

  Pump, vacuum, 149


  Quercitron, 166


  Rag bagging, 11
    boiler, Bertrams', 29
      Donkin's, 30
    cutter, Nuttall's, 24
    cutting-machine, Bertrams', 23
      Donkin's, 26
    engine, 34
      Bentley and Jackson's, 38
      Bertrams', 37
    pulp, 72

  Rags, 11
    Alexandria, 21
    Baltic, 21
    Belgian, 20
    Beyrout, 21
    blue, 19
    boiling, 29
    cotton, 10
    country, 21
    disinfecting, 12
    foreign, 20
    French, 20
    German, 21
    home, 20
    Leghorn, 21
    linen, 10
    new, 20
    Russian, 21
    sorting, 19
    treatment of, 19
    Trieste, 21
    Turkey, 21
    woollen, 21

  Rattan cane, 10

  Raw materials, 10

  Recognition of vegetable fibres by the microscope, 6

  Recovery of soda, American system, 218
    from spent liquor, 204

  Red, cherry, 170
    dark, 170
    litmus paper, 183
    ochre, 172
    pale, 171
    Turkey, 170
    Venetian, 166

  Reds, aniline, 166

  Reeds, 10

  Reeling machine, Bertrams', 197

  Refining or beating, 101
    engine, 159
      Jordan's, 103
    engines, American, Mr. Wyatt on, 103

  Regulating box, 136

  Resin, 6, 115
    oil, 178
    size, 118
    soap, 116

  Resinous soaps, 179

  Retree, 85, 164

  Retting, 4
    process of, 129

  Reversing or plate-glazing calender, 190

  Revolving knife, 161
    cutter, 162
    strainer and knotter, 137

  Rhamnus catharticus, 169

  Ritter and Kellner's process, 71

  Roeckner's boiler, 45
    clarifier, 199
    evaporator, 206
    pulp strainers, 140

  Roll-bar planing machine, 191

  Rolls, couch, 149
    press, 150
    smoothing, 151, 152

  Rope, 20
    bagging, 20
    hard, 20
    tarred, 20
    white, 20

  Round-ribbed fibres, 5

  Royal, 164

  Russian rags, 21

  Ryan's process for treating waste paper, 87


  Sailcloth, 11

  Salt of tartar, 235

  Sampling alkalies, 227

  Sandarac, gum, 179

  Sand-table, 136
    tables, 149
    trap, 50, 136

  Sap green, 169

  Satin papers, stains for, 172

  Save-all, 143

  Sawdust, 10

  Scarlet lake, 171

  Schweinfurth green, 171

  Scoffern and Tidcombe's process for waterproof paper, 174

  Sea grass, 11

  Seaweeds, 178

  Second press-roll, 150

  Seconds rags, 20

  Seconds, whites, 20

  Self-acting dry felt regulator, 186
    cleansing strainer, 139

  Separating tank, 61

  Setting, 174

  Settling of the pulp, 131

  Sfax esparto, 47

  Shavings, paper, 58
    parchment, 171
    wood, 10, 55

  Shoddy, 11

  Silk cocoon waste, 11

  Silver white, 173

  Sinclair's esparto boiler, 42, 43
    process, 58

  Single-cylinder machine, 152

  Single-sheet cutter, 162
    web-winding machine, 188

  Sizal, or sisal hemp, 8

  Size, animal, preparation of, 122
    engine, French method of preparing, 120
    resin, 118

  Sizes of paper, 164

  Sizing, 115
    American method of, 123
    and finishing, 132
    machine, 126
    tub or animal, 122
    Mr. Wyatt's remarks on, 127
    zinc soaps in, 121

  Skip, 153

  Small post, 164

  Smalts blue, 121, 165

  Smoothing presses, three-roll, 194
    rolls, 151, 152

  Soap, Castile, 121
    cotton-seed oil, 121
    resin, 116

  Soaps, zinc, in sizing, 121

  Soda, anhydrous, 225
    ash, 31, 227
    calcined, 93
    carbonate, 31
    caustic, 31
      table showing the quantities of leys of different densities, 243
    dry, Dalton's table, showing the proportion of, in leys of
          different densities, 241
    hydrate of, 225
    hypochlorite of, 8
    hyposulphite of, 110
    ley, caustic, 31
    recovery of, 104
    recovery of, American system of, 218
    solutions, caustic, table showing strength of, 241
    sulphite of, 110
    thiosulphite of, 110, 233

  Sodas, commercial, examination of, 221

  Sodium, chloride of, 95, 109
    hypochlorite of, 96
    thiosulphite of, 233

  Sorting rags, 19, 22

  Sour bleaching, 91

  Souring, 99

  Spanish annotta, 238
    esparto, 47

  Spent liquors, recovery of soda from, 204
    liquors, 218

  Spiral fibres, 8

  Spruce, 60

  Stable manure, 11

  Staining power of ultramarines, 240

  Stains for Morocco papers, 171
    satin papers, 172

  Standard test-acid solution, 225

  Starch paste, 117

  Strainer and knotter, Bertrams' revolving, 137
    self-cleansing, 139

  Strainers, 57, 137
    Roeckner's pulp, 140

  Straw, 16
    boiling, 81
    buckwheat, 10
    fibres, 4
    wheat, 10

  Strength of paper, determination of, 240

  Strings, 20

  Strong linens, 20

  Stuff-chests, 57, 112, 136
    pump, 136

  Sturtevant blower, 60

  Suction boxes, 148

  Sulphate of alumina, 100
    aniline, 8
    copper, 146
    indigo, 232
    iron, 170
    lime, 100
    magnesia, 46
    zinc, 99, 119

  Sulphide processes, 77

  Sulphite fibre, 76
    and resin, 76
    processes, 68
    pulp, 68
    of soda, 110
    wood pulp, 160

  Sulphur, 72, 225

  Sulphuric acid, 47, 91, 99
    anhydrous, 225

  Sulphurous acid, 175
    gas, 55

  Super-calendering, 157
    American, Mr. Wyatt on, 157

  Superfine white cotton, 20

  Superfines, white, 20

  Supply-box, 136

  Surface-sizing, 122

  Susa esparto, 47


  Table of boiling points of alkaline leys, 243
    French and English thermometer scales, 244
    French weights and measures, 245
    showing proportion of dry soda in leys of different densities, 241
    showing the quantity of bleaching liquid to be used, 244
    showing the quantity of bleach liquor required to be added to
          weaker liquors, 244
    showing the quantity of caustic sodas in leys of different
          densities, 243
    showing the specific gravity corresponding with the degrees of
          Baumé's hydrometer, 242
    of strength of caustic soda solutions, 241
    of weights and measures of the metrical system, 245

  Tables and notes, 235
    sand, 149

  Tan waste, 10

  Tarpaulin, 11, 77

  Tarred hemp, 20
    rope, 20
    string, 20

  Tartar, salts of, 235

  Tea colour, 167

  Test acid, preparation of, 224, 225
    for chlorine, 110
    liquor, 232
    papers, 183

  Testing chloride of lime, 232
    ultramarines, 239

  Thermometer scales, comparative French and English, 244

  Thiosulphite of soda, 110
    sodium, 233

  Thirds, whites, 20

  Thompson's bleaching process, 97

  Three-roll smoothing process, 194

  Thune's process, 79

  Tiles, paper, 175

  Tin, citrate of, 169
    perchloride of, 236

  Tobacco stalks, 10

  Toned paper, 165

  Torrance's drainer, 39

  Toughening paper, 178

  Tracing paper, 179

  Tragacanth, gum, 168

  Transparent paper, 179

  Treatment of esparto, 40
    rags, 19, 29
    various fibres, 80
    wood, 53, 68

  Triethyl rose aniline, 98

  Tripoli esparto, 47

  Tub-sizing, 122

  Turmeric paper, 183

  Turkish minium, 170

  Turkey rags, 21
    red, 170

  Turpentine, oil of, 179
    Venice, 179

  Twaddell's hydrometer, 238


  Ultramarine, 121, 165
    artificial, preparation of, 238

  Ultramarines, staining power of, 240
    testing, 239

  Umpherston's beating-engine, 105

  Unbleached cottons, 20


  Vacuum pumps, 149

  Vanadate of ammonia, 72

  Various fibres, treatment of, 80

  Varnished paper, 179

  Varrentrapp's zinc bleach liquor, 100

  Vat for hand paper-making, 129

  Vegetable fibres, micrographic examination of, 5

  Vegetable fibres, recognition of, by the microscope, 6

  Vegeto-mineral paper, 115

  Venetian red, 166

  Venice turpentine, 179

  Verdigris, 169

  Verny's paper-cutting machine, 187

  Violet, 171
    dark, 172
    light, 171

  Vitriol, oil of, 57, 90, 106

  Voelter's process for preparing mechanical wood pulp, 78

  Volumetric assaying, 224

  Vulcanised india-rubber, 223

  Vulcanite, 148


  Washing, American, 61
    boiled esparto, 49
    and breaking, 34
      engine, 37
    cylinder for rag-engine, 193

  Waste, cotton, 10
    cotton-seed, 10
    flax, 10
    hemp, 10
    jute, 10
    linen, 10
    liquors, recovery of soda from, 204
    paper, 10, 85
      boiling, 86
      Ryan's process for, 87
    tan, 10

  Water-marked paper, 130

  Water-marking, 146

  Water-marks, De la Rue's improvements in, 147

  Waterproof composition for paper, 177
    paper, 174
      for flooring, 177
      Jouglet's process, 177
      for roofing, 177

  Watt and Burgess's wood-paper process, 55

  Watt's electrolytic bleaching process, 94

  Wax, 6, 120
    soap, 169

  Web-glazing, 154
    calender, Bertrams', 196

  Web-ripping machine, 198

  Weights and measures, French table of, 245

  Weights and measures of the metrical system, 245

  Wet machines, 57

  White cellulose, 76
    copal, 179
    hemp, 20
    lead, 171
    linens, 20

  Willow and duster, Bertrams', 25
    Masson, Scott, and Co.'s, 40

  Willowing, 24
    esparto, 41

  Wilson's bleach liquor, 100

  Winding machine, single-web, 188

  Wood, acid treatment of, 64
    fibre, 53
    paper, Watt's patent for, 17
    pulp, American method of preparing, 60
    pulp, chemical, 54
    mechanical, 113
    shavings, 10, 55, 77
    pulp, sulphite, 160
    treatment of, 53, 68
    pulp, Voelter's mechanical process for preparing, 78
    waste, dyers', 10

  Woollen rags, 21

  Wrapping papers, 178

  Wright's process for preparing cupro-ammonium, 175

  Writing papers, 164

  Wyatt, Mr., on American refining engines, 103
    on American super-calendering, 157

  Wyatt, Mr., on sizing, 127


  Xyloidin, 67


  Yankee machine, 152

  Yaryan evaporator, 208

  Yellow chrome, 166
    gold envelope, 167
    lake, 238
    ochre, 165, 166
    pale, 172, 173
    pine fibre, 4

  Young's method of bleaching, 100

  Young and Pettigrew's process, 66

  Young's process for cleaning esparto, 50


  Zinc bleach liquor, 99
    chloride of, 99
    oxide of, 99, 100
    salts, 100
    soaps in sizing, 121
    sulphate of, 99, 119

  Zostera marina, 11


PRINTED BY J. S. VIRTUE AND CO., LIMITED, CITY ROAD, LONDON



FOOTNOTES:

[1] Cantor Lectures, _Journal of Society of Arts_, vol. xxvi. p. 74.

[2] Needle-shaped, slender and sharp-pointed.

[3] Manilla hemp.

[4] For this purpose, a microscope having a magnifying power of 120
to 150 diameters will be found efficient.

[5] "Commercial Organic Analysis." By A. H. Allen, F.C.S., vol. i.
p. 316.

[6] For Table of French Measures see end of this work.

[7] _Pectous_, pertaining to or consisting of _pectose_ or
_pectin_. Pectose is a substance contained in the pulp of unripe
fleshy fruit, also in fleshy roots and other vegetable organs.
It is insoluble in water, but under the influence of acids is
transformed into _pectin_.

[8] A _litre_ equals 34 fluid ounces _nearly_.

[9] "Commercial Organic Analysis." By A. H. Allen, F.C.S., vol. i.

[10] _Septa_, plural of _septum_, a partition, as the partitions of
an orange, for example.

[11] "Manufacture of Paper." By C. T. Davis, Philadelphia, 1887.

[12] Patent dated 16th December, 1884, No. 539.

[13] "Forestry and Forest Products," p. 501, and Cross and Bevan's
"Text Book of Paper-making," p. 65.

[14] "Practical Paper Maker," by James Dunbar. Mackenzie and
Storrie, Leith, 1887.

[15] "Practical Treatise on the Manufacture of Paper." By Carl
Hofmann, Philadelphia, 1873.

[16] _The Chemist._ Edited by Charles and John Watt, p. 552; 1855.

[17] _School of Mines Quarterly, a Journal of Applied Science._
Jan., 1889.

[18] The _cord_ is a pile containing 128 cubic feet, or a pile 8
feet long, 4 feet high, and 4 feet broad.

[19] Wagner's "Jahresb." 1860, p. 188.

[20] _Paper-Makers Monthly Journal_, March 15th, 1889.

[21] Sometimes also called _thiosulphite of soda_.

[22] "The Art of Soap-making." By Alexander Watt. London, Crosby
Lockwood and Son, 4th edition, 1890.

[23] Sometimes called "concentrated alum," "pearl alum," etc.

[24] Muspratt's "Chemistry Applied to the Arts."

[25] "Art of Leather Manufacture." By Alexander Watt. Crosby
Lockwood and Son, 1885.

[26] "Proceedings of the Society of Civil Engineers," vol. lxxix.
p. 245.

[27] _Paper-Makers' Monthly Journal_, April 15th, 1889.

[28] The berries of _Rhamnus catharticus_ made into a decoction by
boiling.

[29] _Paper Trade Journal_, New York, April 20th, 1889.

[30] _Sanitary World_, March 29th, 1884.

[31] _Industries_, January 25th, 1889.

[32] "Seventh Annual Report of Local Government Board," 1877-8.

[33] School of Mines _Quarterly Journal of Applied Science_,
January, 1889, New York.

[34] These balances may be obtained from Mr. Oertling, Coppice Row,
London, or of any philosophical instrument maker.

[35] There are two principal methods of analysing or assaying
alkalies by means of the test-acid, namely, _volumetric_, or by
volume, and _gravimetric_, or by weight, in which a specific
gravity bottle, capable of holding exactly 1,000 grains of
distilled water, is used.

[36] New York _Paper Trade Journal_, 1878.


       *       *       *       *       *



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  must prove extremely useful to every practical man possessing a
  copy."--_Practical Engineer._


_=New Manual for Practical Engineers.=_

  _THE PRACTICAL ENGINEER'S HAND-BOOK._ Comprising a Treatise on
  Modern Engines and Boilers: Marine, Locomotive and Stationary.
  And containing a large collection of Rules and Practical Data
  relating to recent Practice in Designing and Constructing all
  kinds of Engines, Boilers, and other Engineering work. The whole
  constituting a comprehensive Key to the Board of Trade and other
  Examinations for Certificates of Competency in Modern Mechanical
  Engineering. By WALTER S. HUTTON, Civil and Mechanical Engineer,
  Author of "The Works' Manager's Handbook for Engineers," &c.
  With upwards of 370 Illustrations. Fourth Edition, Revised, with
  Additions. Medium 8vo, nearly 500 pp., price 18_s._ Strongly
  bound.

==> _This work is designed as a companion to the Author's_ "WORKS'
MANAGER'S HAND-BOOK." _It possesses many new and original features,
and contains, like its predecessor, a quantity of matter not
originally intended for publication, but collected by the author
for his own use in the construction of a great variety of_ MODERN
ENGINEERING WORK.

_The information is given in a condensed and concise form, and is
illustrated by upwards of 370 Woodcuts; and comprises a quantity
of tabulated matter of great value to all engaged in designing,
constructing, or estimating for_ ENGINES, BOILERS, _and_ OTHER
ENGINEERING WORK.

*** OPINIONS OF THE PRESS.

  "We have kept it at hand for several weeks, referring to it as
  occasion arose, and we have not on a single occasion consulted
  its pages without finding the information of which we were in
  quest."--_Athenæum._

  "A thoroughly good practical handbook, which no engineer can go
  through without learning something that will be of service to
  him."--_Marine Engineer._

  "An excellent book of reference for engineers, and a valuable
  text-book for students of engineering."--_Scotsman._

  "This valuable manual embodies the results and experience of the
  leading authorities on mechanical engineering."--_Building News._

  "The author has collected together a surprising quantity of rules
  and practical data, and has shown much judgment in the selections
  he has made.... There is no doubt that this book is one of the
  most useful of its kind published, and will be a very popular
  compendium."--_Engineer._

  "A mass of information, set down in simple language, and in such
  a form that it can be easily referred to at any time. The matter
  is uniformly good and well chosen and is greatly elucidated
  by the illustrations. The book will find its way on to most
  engineers' shelves, where it will rank as one of the most useful
  books of reference."--_Practical Engineer._

  "Full of useful information and should be found on the office
  shelf of all practical engineers."--_English Mechanic._


_=Practical Treatise on Modern Steam-Boilers.=_

  _STEAM-BOILER CONSTRUCTION._ A Practical Handbook for Engineers,
  Boiler-Makers, and Steam Users. Containing a large Collection
  of Rules and Data relating to Recent Practice in the Design,
  Construction, and Working of all Kinds of Stationary, Locomotive,
  and Marine Steam-Boilers. By WALTER S. HUTTON, Civil and
  Mechanical Engineer, Author of "The Works' Manager's Handbook,"
  "The Practical Engineer's Handbook," &c. With upwards of 300
  Illustrations. Second Edition. Medium 8vo, 18_s._ cloth.

==> _This work is issued in continuation of the Series of Handbooks
written by the Author, viz_:--"THE WORKS' MANAGER'S HANDBOOK"
_and_ "THE PRACTICAL ENGINEER'S HANDBOOK," _which are so highly
appreciated by Engineers for the practical nature of their
information; and is consequently written in the same style as those
works_.

The Author believes that the concentration, in a convenient form
for easy reference, of such a large amount of thoroughly practical
information on Steam-Boilers, will be of considerable service to
those for whom it is intended, and he trusts the book may be deemed
worthy of as favourable a reception as has been accorded to its
predecessors.

*** OPINIONS OF THE PRESS.

  "Every detail, both in boiler design and management, is clearly
  laid before the reader. The volume shows that boiler construction
  has been reduced to the condition of one of the most exact
  sciences; and such a book is of the utmost value to the _fin de
  siècle_ Engineer and Works' Manager."--_Marine Engineer._

  "There has long been room for a modern handbook on steam boilers;
  there is not that room now, because Mr. Hutton has filled it. It
  is a thoroughly practical book for those who are occupied in the
  construction, design, selection, or use of boilers."--_Engineer._

  "The book is of so important and comprehensive a character that
  it must find its way into the libraries of everyone interested in
  boiler using or boiler manufacture if they wish to be thoroughly
  informed. We strongly recommend the book for the intrinsic value
  of its contents."--_Machinery Market._

  "The value of this book can hardly be over-estimated. The
  author's rules, formulæ, &c., are all very fresh, and it is
  impossible to turn to the work and not find what you want. No
  practical engineer should be without it."--_Colliery Guardian._


_=Hutton's "Modernised Templeton."=_

  _THE PRACTICAL MECHANICS' WORKSHOP COMPANION._ Comprising a
  great variety of the most useful Rules and Formulæ in Mechanical
  Science, with numerous Tables of Practical Data and Calculated
  Results for Facilitating Mechanical Operations. By WILLIAM
  TEMPLETON, Author of "The Engineer's Practical Assistant," &c.
  &c. Sixteenth Edition, Revised, Modernised, and considerably
  Enlarged by WALTER S. HUTTON, C.E., Author of "The Works'
  Manager's Handbook," "The Practical Engineer's Handbook," &c.
  Fcap. 8vo, nearly 500 pp., with 8 Plates and upwards of 250
  Illustrative Diagrams, 6_s._, strongly bound for workshop or
  pocket wear and tear.

*** OPINIONS OF THE PRESS.

  "In Its modernised form Hutton's 'Templeton' should have a
  wide sale, for it contains much valuable information which the
  mechanic will often find of use, and not a few tables and notes
  which he might look for in vain in other works. This modernised
  edition will be appreciated by all who have learned to value the
  original editions of 'Templeton'.--_English Mechanic._

  "It has met with great success in the engineering workshop, as
  we can testify; and there are a great many men who, in a great
  measure, owe their rise in life to this little book."--_Building
  News._

  "This familiar text-book--well known to all mechanics and
  engineers--is of essential service to the every-day requirements
  of engineers, millwrights, and the various trades connected with
  engineering and building. The new modernised edition is worth its
  weight in gold."--_Building News._ (Second Notice.)

  "This well-known and largely-used book contains information,
  brought up to date, of the sort so useful to the foreman and
  draughtsman. So much fresh information has been introduced as to
  constitute it practically a new book. It will be largely used in
  the office and workshop."--_Mechanical World._

  "The publishers wisely entrusted the task of revision of this
  popular, valuable, and useful book to Mr. Hutton, than whom a
  more competent man they could not have found."--_Iron._


_=Templeton's Engineer's and Machinist's Assistant.=_

  _THE ENGINEER'S, MILLWRIGHT'S, and MACHINIST'S PRACTICAL
  ASSISTANT._ A collection of Useful Tables, Rules and Data. By
  WILLIAM TEMPLETON. 7th Edition, with Additions. 18mo, 2_s._ 6_d._
  cloth.

*** OPINIONS OF THE PRESS.

  "Occupies a foremost place among books of this kind. A more
  suitable present to an apprentice to any of the mechanical trades
  could not possibly be made."--_Building News._

  "A deservedly popular work. It should be in the 'drawer' of every
  mechanic."--_English Mechanic._


_=Foley's Office Reference Book for Mechanical Engineers.=_

  _THE MECHANICAL ENGINEER'S REFERENCE BOOK_, for Machine and
  Boiler Construction. In Two Parts. Part I. GENERAL ENGINEERING
  DATA. Part II. BOILER CONSTRUCTION. With 51 Plates and numerous
  Illustrations. By NELSON FOLEY, M.I.N.A. Folio, £5 5_s._
  half-bound.

SUMMARY OF CONTENTS.

PART I.

MEASURES.--CIRCUMFERENCES AND AREAS, &C., SQUARES, CUBES,
FOURTH POWERS.--SQUARE AND CUBE ROOTS.--SURFACE OF
TUBES--RECIPROCALS.--LOGARITHMS.--MENSURATION.--SPECIFIC GRAVITIES
AND WEIGHTS.--WORK AND POWER.--HEAT.--COMBUSTION.--EXPANSION
AND CONTRACTION.--EXPANSION OF GASES.--STEAM.--STATIC
FORCES.--GRAVITATION AND ATTRACTION.--MOTION AND
COMPUTATION OF RESULTING FORCES.--ACCUMULATED
WORK.--CENTRE AND RADIUS OF GYRATION.--MOMENT OF
INERTIA.--CENTRE OF OSCILLATION.--ELECTRICITY.--STRENGTH
OF MATERIALS.--ELASTICITY.--TEST SHEETS OF
METALS.--FRICTION.--TRANSMISSION OF POWER.--FLOW OF LIQUIDS.--FLOW
OF GASES.--AIR PUMPS, SURFACE CONDENSERS, &C.--SPEED OF
STEAMSHIPS.--PROPELLERS.--CUTTING TOOLS.--FLANGES.--COPPER SHEETS
AND TUBES.--SCREWS, NUTS, BOLT HEADS, &C.--VARIOUS RECIPES AND
MISCELLANEOUS MATTER.

  WITH DIAGRAMS FOR VALVE-GEAR, BELTING AND ROPES, DISCHARGE AND
  SUCTION PIPES, SCREW PROPELLERS, AND COPPER PIPES.

PART II.

TREATING OF, POWER OF BOILERS.--USEFUL RATIOS.--NOTES
ON CONSTRUCTION.--CYLINDRICAL BOILER SHELLS.--CIRCULAR
FURNACES.--FLAT PLATES--STAYS.--GIRDERS.--SCREWS.--HYDRAULIC
TESTS.--RIVETING.--BOILER SETTING, CHIMNEYS, AND MOUNTINGS.--FUELS,
&C.--EXAMPLES OF BOILERS AND SPEEDS OF STEAMSHIPS.--NOMINAL AND
NORMAL HORSE POWER.

  WITH DIAGRAMS FOR ALL BOILER CALCULATIONS AND DRAWINGS OF MANY
  VARIETIES OF BOILERS.

*** OPINIONS OF THE PRESS.

  "This appears to be a work for which there should be a large
  demand on the part of mechanical engineers. It is no easy
  matter to compile a book of this class, and the labour involved
  is enormous, particularly when--as the author informs us--the
  majority of the tables and diagrams have been specially prepared
  for the work. The diagrams are exceptionally well executed, and
  generally constructed on the method adopted in a previous work
  by the same author.... The tables are very numerous, and deal
  with a greater variety of subjects than will generally be found
  in a work of this kind; they have evidently been compiled with
  great care and are unusually complete. All the information given
  appears to be well up to date.... It would be quite impossible
  within the limits at our disposal to even enumerate all the
  subjects treated; it should, however, be mentioned that the
  author does not confine himself to a mere bald statement of
  formulæ and laws, but in very many instances shows succinctly
  how these are derived.... The latter part of the book is devoted
  to diagrams relating to Boiler Construction, and to nineteen
  beautifully-executed plates of working drawings of boilers and
  their details. As samples of how such drawings should be got out,
  they may be cordially recommended to the attention of all young,
  and even some elderly, engineers.... Altogether the book is one
  which every mechanical engineer may, with advantage to himself
  add to his library."--_Industries._

  "Mr. Foley is well fitted to compile such a work.... The diagrams
  are a great feature of the work.... Regarding the whole work, it
  may be very fairly stated that Mr. Foley has produced a volume
  which will undoubtedly fulfil the desire of the author and become
  indispensable to all mechanical engineers."--_Marine Engineer._

  "We have carefully examined this work, and pronounce it
  a most excellent reference book for the use of marine
  engineers."--_Journal of American Society of Naval Engineers._

  "A veritable monument of industry on the part of Mr. Foley, who
  has succeeded in producing what is simply invaluable to the
  engineering profession."--_Steamship._


_=Coal and Speed Tables.=_

  _A POCKET BOOK OF COAL AND SPEED TABLES, for Engineers and
  Steam-users._ By NELSON FOLEY, Author of "The Mechanical
  Engineer's Reference Book." Pocket-size, 3_s._ 6_d._ cloth.

  "These tables are designed to meet the requirements of every-day
  use; they are of sufficient scope for most practical purposes,
  and may be commended to engineers and users of steam."--_Iron._

  "This pocket-book well merits the attention of the practical
  engineer. Mr. Foley has compiled a very useful set of tables,
  the information contained in which is frequently required by
  engineers, coal consumers and users of steam."--_Iron and Coal
  Trades Review._


_=Steam Engine.=_

  _TEXT-BOOK ON THE STEAM ENGINE._ With a Supplement on Gas
  Engines, and PART II. ON HEAT ENGINES. By T. M. GOODEVE, M.A.,
  Barrister-at-Law, Professor of Mechanics at the Royal College
  of Science, London; Author of "The Principles of Mechanics,"
  "The Elements of Mechanism," &c. Twelfth Edition, Enlarged. With
  numerous Illustrations. Crown 8vo, 6_s._ cloth.

  "Professor Goodeve has given us a treatise on the steam engine
  which will bear comparison with anything written by Huxley or
  Maxwell, and we can award it no higher praise."--_Engineer._

  "Mr. Goodeve's text-book is a work of which every young engineer
  should possess himself."--_Mining Journal._


_=Gas Engines.=_

  _ON GAS-ENGINES._ With Appendix describing a Recent Engine with
  Tube Igniter. By T. M. GOODEVE, M.A. Crown 8vo, 2_s._ 6_d._ cloth.

  [_Just published._

  "Like all Mr. Goodeve's writings, the present is no exception
  in point of general excellence. It is a valuable little
  volume."--_Mechanical World._


_=Steam Engine Design.=_

  _A HANDBOOK ON THE STEAM ENGINE_, with especial Reference to
  Small and Medium-sized Engines. For the Use of Engine-Makers,
  Mechanical Draughtsmen, Engineering Students and Users of Steam
  Power. By HERMAN HAEDER, C.E. English Edition, Re-edited by the
  Author from the Second German Edition, and Translated, with
  considerable Additions and Alterations, by H. H. P. POWLES,
  A.M.I.C.E., M.I.M.E. With nearly 1,100 Illustrations. Crown 8vo,
  9_s._ cloth.

  "A perfect encyclopædia of the steam engine and its details, and
  one which must take a permanent place in English drawing-offices
  and workshops."--_A Foreman Pattern-maker._

  "This is an excellent book, and should be in the hands of all who
  are interested in the construction and design of medium sized
  stationary engines.... A careful study of its contents and the
  arrangement of the sections leads to the conclusion that there is
  probably no other book like it in this country. The volume aims
  at showing the results of practical experience, and it certainly
  may claim a complete achievement of this idea."--_Nature._

  "There can be no question as to its value. We cordially commend
  it to all concerned in the design and construction of the steam
  engine."--_Mechanical World._


_=Steam Boilers.=_

  _A TREATISE ON STEAM BOILERS: Their Strength, Construction, and
  Economical Working._ By ROBERT WILSON, C.E. Fifth Edition. 12mo,
  6_s._ cloth.

  "The best treatise that has ever been published on steam
  boilers."--_Engineer._

  "The author shows himself perfect master of his subject, and
  we heartily recommend all employing steam power to possess
  themselves of the work."--_Ryland's Iron Trade Circular._


_=Boiler Chimneys.=_

  _BOILER AND FACTORY CHIMNEYS: Their Draught-Power and Stability._
  With a Chapter on _Lightning Conductors_. By ROBERT WILSON,
  A.I.C.E., Author of "A Treatise on Steam Boilers," &c. Second
  Edition. Crown 8vo, 3_s._ 6_d._ cloth.

  "A valuable contribution to the literature of scientific
  building."--_The Builder._


_=Boiler Making.=_

  _THE BOILER-MAKER'S READY RECKONER & ASSISTANT._ With Examples of
  Practical Geometry and Templating, for the Use of Platers, Smiths
  and Riveters. By JOHN COURTNEY, Edited by D. K. CLARK, M.I.C.E.
  Third Edition, 480 pp., with 140 Illusts. Fcap. 8vo, 7_s._
  half-bound.

  "No workman or apprentice should be without this book."--_Iron
  Trade Circular._


_=Locomotive Engine Development.=_

  _THE LOCOMOTIVE ENGINE AND ITS DEVELOPMENT._ A Popular Treatise
  on the Gradual Improvements made in Railway Engines between 1803
  and 1893. By CLEMENT E. STRETTON, C.E., Author of "Safe Railway
  Working," &c. Second Edition, Revised and much Enlarged. With 95
  Illustrations. Crown 8vo, 3_s._ 6_d._ cloth.

  [_Just published._

  "Students of railway history and all who are interested in the
  evolution of the modern locomotive will find much to attract and
  entertain in this volume."--_The Times._

  "The author of this work is well known to the railway world,
  and no one probably has a better knowledge of the history and
  development of the locomotive. The volume before us should
  be of value to all connected with the railway system of this
  country."--_Nature._


_=Fire Engineering.=_

  _FIRES, FIRE-ENGINES, AND FIRE-BRIGADES._ With a History of
  Fire-Engines, their Construction, Use, and Management; Remarks
  on Fire-Proof Buildings, and the Preservation of Life from Fire;
  Statistics of the Fire Appliances in English Towns; Foreign Fire
  Systems Hints on Fire-Brigades, &c. &c. By CHARLES F. T. YOUNG,
  C.E. With numerous Illustrations. 544 pp., demy 8vo, £1 4_s._
  cloth.

  "To those interested in the subject of fires and fire apparatus,
  we most heartily commend this book. It is the only English work
  we now have upon the subject."--_Engineering._

  "It displays much evidence of careful research; and Mr. Young
  has put his facts neatly together. His acquaintance with the
  practical details of the construction of steam fire engines,
  old and new, and the conditions with which it is necessary they
  should comply, is accurate and full."--_Engineer._


_=Estimating for Engineering Work, &c.=_

  _ENGINEERING ESTIMATES, COSTS AND ACCOUNTS_: A Guide to
  Commercial Engineering. With numerous Examples of Estimates
  and Costs of Millwright Work, Miscellaneous Productions, Steam
  Engines and Steam Boilers; and a Section on the Preparation of
  Costs Accounts. By A GENERAL MANAGER. Demy 8vo, 12_s._ cloth.

  "This is an excellent and very useful book, covering
  subject-matter in constant requisition in every factory and
  workshop.... The book is invaluable, not only to the young
  engineer, but also to the estimate department of every
  works."--BUILDER.

  "We accord the work unqualified praise. The information is given
  in a plain, straightforward manner, and bears throughout evidence
  of the intimate practical acquaintance of the author with every
  phase of commercial engineering."--MECHANICAL WORLD.


_=Engineering Construction.=_

  _PATTERN-MAKING: A Practical Treatise_, embracing the Main Types
  of Engineering Construction, and including Gearing, both Hand
  and Machine made, Engine Work, Sheaves and Pulleys, Pipes and
  Columns, Screws, Machine Parts, Pumps and Cocks, the Moulding of
  Patterns in Loam and Greensand, &c., together with the methods
  of Estimating the weight of Castings; to which is added an
  Appendix of Tables for Workshop Reference. By A FOREMAN PATTERN
  MAKER. Second Edition, thoroughly Revised and much Enlarged. With
  upwards of 450 Illustrations. Crown 8vo, 7_s._ 6_d._ cloth.

  [_Just published._

  "A well-written technical guide, evidently written by a man who
  understands and has practised what he has written about.... We
  cordially recommend it to engineering students, young journeymen,
  and others desirous of being initiated into the mysteries of
  pattern-making."--_Builder._

  "More than 450 illustrations help to explain the text, which is,
  however, always clear and explicit, thus rendering the work an
  excellent _vade mecum_ for the apprentice who desires to become
  master of his trade."--_English Mechanic._


_=Dictionary of Mechanical Engineering Terms.=_

  _LOCKWOOD'S DICTIONARY OF TERMS USED IN THE PRACTICE OF
  MECHANICAL ENGINEERING_, embracing those current in the Drawing
  Office, Pattern Shop, Foundry, Fitting, Turning, Smith's and
  Boiler Shops, &c. &c. Comprising upwards of 6,000 Definitions.
  Edited by A FOREMAN PATTERN-MAKER, Author of "Pattern Making."
  Second Edition, Revised, with Additions. Crown 8vo, 7_s._ 6_d._
  cloth.

  "Just the sort of handy dictionary required by the various trades
  engaged in mechanical engineering. The practical engineering
  pupil will find the book of great value in his studies, and every
  foreman engineer and mechanic should have a copy."--_Building
  News._

  "Not merely a dictionary, but, to a certain extent, also a most
  valuable guide. It strikes us as a happy idea to combine with a
  definition of the phrase useful information on the subject of
  which it treats."--_Machinery Market._


_=Mill Gearing.=_

  _TOOTHED GEARING_: A Practical Handbook for Offices and
  Workshops. By A FOREMAN PATTERN MAKER, Author of "Pattern
  Making," "Lockwood's Dictionary of Mechanical Engineering Terms,"
  &c. With 184 Illustrations. Crown 8vo, 6_s._ cloth.

  [_Just published._

SUMMARY OF CONTENTS.

CHAP. I. PRINCIPLES.--II. FORMATION OF TOOTH PROFILES.--III.
PROPORTIONS OF TEETH.--IV. METHODS OF MAKING TOOTH FORMS.--V.
INVOLUTE TEETH.--VI. SOME SPECIAL TOOTH FORMS.--VII. BEVEL
WHEELS.--VIII. SCREW GEARS.--IX. WORM GEARS.--X. HELICAL
WHEELS.--XI. SKEW BEVELS.--XII. VARIABLE AND OTHER GEARS.--XIII.
DIAMETRICAL PITCH.--XIV. THE ODONTOGRAPH.--XV. PATTERN GEARS.--XVI.
MACHINE MOULDING GEARS.--XVII. MACHINE CUT GEARS.--XVIII.
PROPORTION OF WHEELS.

  "We must give the book our unqualified praise for its
  thoroughness of treatment, and we can heartily recommend it to
  all interested as the most practical book on the subject yet
  written.--_Mechanical World._


_=Stone-working Machinery.=_

  _STONE-WORKING MACHINERY, and the Rapid and Economical Conversion
  of Stone._ With Hints on the Arrangement and Management of Stone
  Works. By M. POWIS BALE, M.I.M.E. With Illusts. Crown 8vo, 9_s._

  "The book should be in the hands of every mason or student of
  stone-work."--_Colliery Guardian._

  "A capital handbook for all who manipulate stone for building or
  ornamental purposes."--_Machinery Market._


_=Pump Construction and Management.=_

  _PUMPS AND PUMPING: A Handbook for Pump Users._ Being Notes
  on Selection, Construction and Management. By M. POWIS BALE,
  M.I.M.E., Author of "Woodworking Machinery," "Saw Mills," &c.
  Second Edition, Revised. Crown 8vo, 2_s._ 6_d._ cloth.

  "The matter is set forth as concisely as possible. In fact,
  condensation rather than diffuseness has been the author's aim
  throughout; yet he does not seem to have omitted anything likely
  to be of use."--_Journal of Gas Lighting._

  "Thoroughly practical and simply and clearly written."--_Glasgow
  Herald._


_=Milling Machinery, etc.=_

  _MILLING MACHINES AND PROCESSES: A Practical Treatise on Shaping
  Metals by Rotary Cutters_, including Information on Making and
  Grinding the Cutters. By PAUL N. HASLUCK, Author of "Lathe-work,"
  "Handybooks for Handicrafts," &c. With upwards of 300 Engravings,
  including numerous Drawings by the Author. Large crown 8vo, 352
  pages, 12_s._ 6_d._ cloth.

  "A new departure in engineering literature.... We can recommend
  this work to all interested in milling machines; it is what it
  professes to be--a practical treatise."--_Engineer._

  "A capital and reliable book, which will no doubt be of
  considerable service, both to those who are already acquainted
  with the process as well as to those who contemplate its
  adoption."--_Industries._


_=Turning.=_

  _LATHE-WORK: A Practical Treatise on the Tools, Appliances, and
  Processes employed in the Art of Turning_. By PAUL N. HASLUCK.
  Fourth Edition, Revised and Enlarged. Cr. 8vo, 5_s._ cloth.

  "Written by a man who knows, not only how work ought to be
  done, but who also knows how to do it, and how to convey
  his knowledge to others. To all turners this book would be
  valuable."--_Engineering._

  "We can safely recommend the work to young engineers. To the
  amateur it will simply be invaluable. To the student it will
  convey a great deal of useful information."--_Engineer._


_=Screw-Cutting.=_

  _SCREW THREADS: And Methods of Producing Them._ With Numerous
  Tables, and complete directions for using Screw-Cutting
  Lathes. By PAUL N. HASLUCK, Author of "Lathe-Work," &c. With
  Seventy-four Illustrations. Third Edition, Revised and Enlarged.
  Waistcoat-pocket size, 1_s._ 6_d._ cloth.

  "Full of useful information, hints and practical criticism. Taps,
  dies and screwing-tools generally are illustrated and their
  action described."--_Mechanical World._

  "It is a complete compendium of all the details of the
  screw-cutting lathe; in fact a _multum in parvo_ on all the
  subjects it treats upon."--_Carpenter and Builder._


_=Smith's Tables for Mechanics, etc.=_

  _TABLES, MEMORANDA, AND CALCULATED RESULTS, FOR MECHANICS,
  ENGINEERS, ARCHITECTS, BUILDERS, etc._ Selected and Arranged by
  FRANCIS SMITH. Fifth Edition, thoroughly Revised and Enlarged,
  with a New Section of ELECTRICAL TABLES, FORMULÆ, and MEMORANDA.
  Waistcoat-pocket size, 1_s._ 6_d._ limp leather.

  "It would, perhaps, be as difficult to make a small pocket-book
  selection of notes and formulæ to suit ALL engineers as
  it would be to make a universal medicine; but Mr. Smith's
  waistcoat-pocket collection may be looked upon as a successful
  attempt."--_Engineer._

  "The best example we have ever seen of 270 pages of useful matter
  packed into the dimensions of a card-case."--_Building News._

  "A veritable pocket treasury of knowledge."--_Iron._


_=French-English Glossary for Engineers, etc.=_

  _A POCKET GLOSSARY of TECHNICAL TERMS: ENGLISH-FRENCH,
  FRENCH-ENGLISH_; with Tables suitable for the Architectural,
  Engineering, Manufacturing and Nautical Professions. By JOHN
  JAMES FLETCHER, Engineer and Surveyor. Second Edition, Revised
  and Enlarged, 200 pp. Waistcoat-pocket size, 1_s._ 6_d._ limp
  leather.

  "It is a very great advantage for readers and correspondents
  in France and England to have so large a number of the words
  relating to engineering and manufacturers collected in a
  Liliputian volume. The little book will be useful both to
  students and travellers."--_Architect._

  "The glossary of terms is very complete, and many of the
  tables are new and well arranged. We cordially commend the
  book."--_Mechanical World._


_=Year-Book of Engineering Formulæe, &c.=_

  _THE ENGINEER'S YEAR-BOOK FOR 1894._ Comprising Formulæ, Rules,
  Tables, Data and Memoranda in Civil, Mechanical, Electrical,
  Marine and Mine Engineering. By H. R. KEMPE, A.M. Inst.C.E.,
  M.I.E.E., Technical Officer of the Engineer-in-Chief's Office.
  General Post Office, London, Author of "A Handbook of Electrical
  Testing," "The Electrical Engineer's Pocket-Book," &c. With 700
  Illustrations, specially Engraved for the work. Crown 8vo, 600
  pages, 8_s._ leather.

  [_Just published._

  "Represents an enormous quantity of work, and forms a desirable
  book of reference."--_The Engineer._

  "The book is distinctly in advance of most similar publications
  in this country."--_Engineering._

  "This valuable and well-designed book of reference meets the
  demands of all descriptions of engineers."--_Saturday Review._

  "Teems with up-to-date information in every branch of engineering
  and construction."--_Building News._

  "The needs of the engineering profession could hardly be supplied
  in a more admirable, complete and convenient form. To say that it
  more than sustains all comparisons is praise of the highest sort,
  and that may justly be said of it."--_Mining Journal._

  "There is certainly room for the new comer, which supplies
  explanations and directions, as well as formulæ and tables. It
  deserves to become one of the most successful of the technical
  annuals."--_Architect._

  "Brings together with great skill all the technical information
  which an engineer has to use day by day. It is in every way
  admirably equipped, and is sure to prove successful."--_Scotsman._

  "The up-to-dateness of Mr. Kempe's compilation is a quality
  that will not be lost on the busy people for whom the work is
  intended."--_Glasgow Herald._


_=Portable Engines.=_

  _THE PORTABLE ENGINE; ITS CONSTRUCTION AND MANAGEMENT._ A
  Practical Manual for Owners and Users of Steam Engines generally.
  By WILLIAM DYSON WANSBROUGH. With 90 Illustrations. Crown 8vo,
  3_s._ 6_d._ cloth.

  "This is a work of value to those who use steam machinery....
  Should be read by everyone who has a steam engine, on a farm or
  elsewhere."--_Mark Lane Express._

  "We cordially commend this work to buyers and owners of steam
  engines, and to those who have to do with their construction or
  use."--_Timber Trades Journal._

  "Such a general knowledge of the steam engine as Mr. Wansbrough
  furnishes to the reader should be acquired by all intelligent
  owners and others who use the steam engine."--_Building News._

  "An excellent text-book of this useful form of engine. 'The Hints
  to Purchasers' contain a good deal of commonsense and practical
  wisdom."--_English Mechanic._


_=Iron and Steel.=_

  _"IRON AND STEEL": A Work for the Forge, Foundry, Factory, and
  Office._ Containing ready, useful, and trustworthy Information
  for Iron-masters and their Stock-takers; Managers of Bar, Rail,
  Plate, and Sheet Rolling Mills: Iron and Metal Founders; Iron
  Ship and Bridge Builders; Mechanical, Mining, and Consulting
  Engineers; Architects, Contractors, Builders, and Professional
  Draughtsmen. By CHARLES HOARE, Author of "The Slide Rule," &c.
  Eighth Edition, Revised throughout and considerably Enlarged.
  32mo. 6_s._ leather.

  "For comprehensiveness the book has not its equal."--_Iron._

  "One of the best of the pocket books."--_English Mechanic._

  "We cordially recommend this book to those engaged in considering
  the details of all kinds of iron and steel works."--_Naval
  Science._


_=Elementary Mechanics.=_

  _CONDENSED MECHANICS._ A Selection of Formulæ, Rules, Tables,
  and Data for the Use of Engineering Students, Science Classes,
  &c. In Accordance with the Requirements of the Science and Art
  Department. By W. G. CRAWFORD HUGHES, A.M.I.C.E. Crown 8vo, 2_s._
  6_d._ cloth.

  "The book is well fitted for those who are either confronted
  with practical problems in their work, or are preparing for
  examination and wish to refresh their knowledge by going through
  their formulæ again."--_Marine Engineer._

  "It is well arranged, and meets the wants of those for whom it is
  intended."--_Railway News._


_=Steam.=_

  _THE SAFE USE OF STEAM._ Containing Rules for Unprofessional
  Steam-users. By an ENGINEER. Sixth Edition. Sewed, 6_d._

  "If steam-users would but learn this little book by heart, boiler
  explosions would become sensations by their rarity."--_English
  Mechanic._


_=Warming.=_

  _HEATING BY HOT WATER_: with Information and Suggestions on
  the best Methods of Heating Public, Private and Horticultural
  Buildings. By WALTER JONES. Second Edition. With 96
  Illustrations. Crown 8vo, 2_s._ 6_d._ _net_.

  "We confidently recommend all interested in heating by hot water
  to secure a copy of this valuable little treatise."--_The Plumber
  and Decorator._


_THE POPULAR WORKS OF MICHAEL REYNOLDS_

("THE ENGINE DRIVER'S FRIEND").


_=Locomotive-Engine Driving.=_

  _LOCOMOTIVE-ENGINE DRIVING: A Practical Manual for Engineers in
  charge of Locomotive Engines._ By MICHAEL REYNOLDS, Member of the
  Society of Engineers, formerly Locomotive Inspector L. B. and S.
  C. R. Ninth Edition. Including a KEY TO THE LOCOMOTIVE ENGINE.
  With Illustrations and Portrait of Author. Crown 8vo. 4_s._ 6_d._
  cloth.

  "Mr. Reynolds has supplied a want, and has supplied it well. We
  can confidently recommend the book, not only to the practical
  driver, but to everyone who takes an interest in the performance
  of locomotive engines."--_The Engineer._

  "Mr. Reynolds has opened a new chapter in the literature
  of the day. This admirable practical treatise, of the
  practical utility of which we have to speak in terms of warm
  commendation."--_Athenæum._

  "Evidently the work of one who knows his subject
  thoroughly."--_Railway Service Gazette._

  "Were the cautions and rules given in the book to become part of
  the every-day working of our engine-drivers, we might have fewer
  distressing accidents to deplore."--_Scotsman._


_=Stationary Engine Driving.=_

  _STATIONARY ENGINE DRIVING: A Practical Manual for Engineers
  in charge of Stationary Engines._ By MICHAEL REYNOLDS. Fifth
  Edition, Enlarged. With Plates and Woodcuts. Crown 8vo, 4_s._
  6_d._ cloth.

  "The author is thoroughly acquainted with his subjects, and his
  advice on the various points treated is clear and practical....
  He has produced a manual which is an exceedingly useful one for
  the class for whom it is specially intended."--_Engineering._

  "Our author leaves no stone unturned. He is determined that
  his readers shall not only know something about the stationary
  engine, but all about it."--_Engineer._

  "An engineman who has mastered the contents of Mr.Reynolds's
  book will require but little actual experience with boilers and
  engines before he can be trusted to look after them."--_English
  Mechanic._


_=The Engineer, Fireman, and Engine-Boy.=_

  _THE MODEL LOCOMOTIVE ENGINEER, FIREMAN, and ENGINE-BOY._
  Comprising a Historical Notice of the Pioneer Locomotive
  Engines and their Inventors. By MICHAEL REYNOLDS. With numerous
  Illustrations and a fine Portrait of George Stephenson. Crown
  8vo, 4_s._ 6_d._ cloth.

  "From the technical knowledge of the author it will appeal to the
  railway man of to-day more forcibly than anything written by Dr.
  Smiles.... The volume contains information of a technical kind,
  and facts that every driver should be familiar with."--_English
  Mechanic._

  "We should be glad to see this book in the possession of everyone
  in the kingdom who has ever laid, or is to lay, hands on a
  locomotive engine."--_Iron._


_=Continuous Railway Brakes.=_

  _CONTINUOUS RAILWAY BRAKES: A Practical Treatise on the several
  Systems in Use in the United Kingdom; their Construction and
  Performance._ With copious Illustrations and numerous Tables. By
  MICHAEL REYNOLDS. Large crown 8vo, 9_s._ cloth.

  "A popular explanation of the different brakes. It will be
  of great assistance in forming public opinion, and will be
  studied with benefit by those who take an interest in the
  brake."--_English Mechanic._

  "Written with sufficient technical detail to enable the principle
  and relative connection of the various parts of each particular
  brake to be readily grasped."--_Mechanical World._


_=Engine-Driving Life.=_

  _ENGINE-DRIVING LIFE: Stirring Adventures and Incidents in the
  Lives of Locomotive-Engine Drivers._ By MICHAEL REYNOLDS. Third
  and Cheaper Edition. Crown 8vo, 1_s._ 6_d._ cloth.

  [_Just published._

  "From first to last perfectly fascinating. Wilkie Collins's
  most thrilling conceptions are thrown into the shade by
  true incidents, endless in their variety, related in every
  page."--_North British Mail._

  "Anyone who wishes to get a real insight into railway life cannot
  do better than read 'Engine-Driving Life' for himself; and if he
  once take it up he will find that the author's enthusiasm and
  real love of the engine-driving profession will carry him on till
  he has read every page."--_Saturday Review._


_=Pocket Companion for Enginemen.=_

  _THE ENGINEMAN'S POCKET COMPANION AND PRACTICAL EDUCATOR FOR
  ENGINEMEN, BOILER ATTENDANTS, AND MECHANICS._ By MICHAEL
  REYNOLDS. With Forty-five Illustrations and numerous Diagrams.
  Third Edition, Revised. Royal 18mo, 3_s._ 6_d._, strongly bound
  for pocket wear.

  "This admirable work is well suited to accomplish its object,
  being the honest workmanship of a competent engineer."--_Glasgow
  Herald._

  "A most meritorious work, giving in a succinct and practical form
  all the information an engine-minder desirous of mastering the
  scientific principles of his daily calling would require."--_The
  Miller._

  "A boon to those who are striving to become efficient
  mechanics."--_Daily Chronicle._


CIVIL ENGINEERING, SURVEYING, etc.

_MR. HUMBER'S VALUABLE ENGINEERING BOOKS._


_=The Water Supply of Cities and Towns.=_

  _A COMPREHENSIVE TREATISE on the WATER-SUPPLY OF CITIES AND
  TOWNS._ By WILLIAM HUMBER, A-M.Inst.C.E., and M. Inst. M.E.,
  Author of "Cast and Wrought Iron Bridge Construction," &c. &c.
  Illustrated with 50 Double Plates, 1 Single Plate, Coloured
  Frontispiece, and upwards of 250 Woodcuts, and containing 400
  pages of Text. Imp. 4to, £6 6_s._ elegantly and substantially
  half-bound in morocco.

_List of Contents._

I. Historical Sketch of some of the means that have been adopted
for the Supply of Water to Cities and Towns.--II. Water and the
Foreign Matter usually associated with it.--III. Rainfall and
Evaporation.--IV. Springs and the water-bearing formations of
various districts.--V. Measurement and Estimation of the flow
of Water.--VI. On the Selection of the Source of Supply.--VII.
Wells.--VIII. Reservoirs.--IX. The Purification of Water.--X.
Pumps.--XI. Pumping Machinery.--XII. Conduits.--XIII. Distribution
of Water.--XIV. Meters, Service Pipes, and House Fittings.--XV. The
Law and Economy of Water Works.--XVI. Constant and Intermittent
Supply.--XVII. Description of Plates.--Appendices, giving Tables of
Rates of Supply, Velocities, &c. &c., together with Specifications
of several Works illustrated, among which will be found: Aberdeen,
Bideford, Canterbury, Dundee. Halifax, Lambeth, Rotherham, Dublin,
and others.

  "The most systematic and valuable work upon water supply hitherto
  produced in English, or in any other language.... Mr. Humber's
  work is characterised almost throughout by an exhaustiveness much
  more distinctive of French and German than of English technical
  treatises."--_Engineer._

  "We can congratulate Mr. Humber on having been able to give so
  large an amount of Information on a subject so important as the
  water supply of cities and towns. The plates, fifty in number,
  are mostly drawings of executed works, and alone would have
  commanded the attention of every engineer whose practice may lie
  in this branch of the profession."--_Builder._


_=Cast and Wrought Iron Bridge Construction.=_

  _A COMPLETE AND PRACTICAL TREATISE ON CAST AND WROUGHT IRON
  BRIDGE CONSTRUCTION, including Iron Foundations._ In Three
  Parts--Theoretical, Practical, and Descriptive. By WILLIAM
  HUMBER, A.M.Inst.C.E., and M.Inst.M.E. Third Edition, Revised
  and much improved, with 115 Double Plates (20 of which now first
  appear in this edition), and numerous Additions to the Text. In
  Two Vols., imp. 4to, £6 16_s._ 6_d._ half-bound in morocco.

  "A very valuable contribution to the standard literature of civil
  engineering. In addition to elevations, plans and sections, large
  scale details are given which very much enhance the instructive
  worth of those illustrations."--_Civil Engineer and Architect's
  Journal._

  "Mr. Humber's stately volumes, lately issued--in which the
  most important bridges erected during the last five years,
  under the direction of the late Mr. Brunel, Sir W. Cubitt, Mr.
  Hawkshaw, Mr. Page, Mr. Fowler, Mr. Hemans, and others among
  our most eminent engineers, are drawn and specified in great
  detail."--_Engineer._


_=Strains, Calculation of.=_

  _A HANDY BOOK FOR THE CALCULATION OF STRAINS IN GIRDERS AND
  SIMILAR STRUCTURES, AND THEIR STRENGTH._ Consisting of Formulæ
  and Corresponding Diagrams, with numerous details for Practical
  Application, &c. By WILLIAM HUMBER, A-M.Inst.C.E., &c. Fifth
  Edition. Crown 8vo, nearly 100 Woodcuts and 3 Plates, 7_s._ 6_d._
  cloth.

  "The formulae are neatly expressed, and the diagrams
  good."--_Athenæum._

  "We heartily commend this really _handy_ book to our engineer and
  architect readers."--_English Mechanic._


_=Barlow's Strength of Materials, enlarged by Humber.=_

  _A TREATISE ON THE STRENGTH OF MATERIALS_: with Rules for
  Application in Architecture, the Construction of Suspension
  Bridges, Railways, &c. By PETER BARLOW, F.R.S. A New Edition,
  Revised by his Sons, P. W. BARLOW, F.R.S., and W. H. BARLOW,
  F.R.S.; to which are added, Experiments by HODGKINSON, FAIRBAIRN,
  and KIRKALDY; and Formulæ for Calculating Girders, &c. Arranged
  and Edited by WM. HUMBER, A-M.Inst.C.E. Demy 8vo, 400 pp., with
  19 large Plates and numerous Woodcuts, 18_s._ cloth.

  "Valuable alike to the student, tyro, and the experienced
  practitioner, it will always rank future, as it has
  hitherto done, as the standard treatise on that particular
  subject."--_Engineer._

  "There is no greater authority than Barlow."--_Building News._

  "As a scientific work of the first class, it deserves a foremost
  place on the bookshelves of every civil engineer and practical
  mechanic."--_English Mechanic._


_MR. HUMBER'S GREAT WORK ON MODERN ENGINEERING._

Complete in Four Volumes, imperial 4to, price £12 12_s._,
half-morocco. Each Volume sold separately as follows:--


  _A RECORD OF THE PROGRESS OF MODERN ENGINEERING._ FIRST SERIES.
  Comprising Civil, Mechanical, Marine, Hydraulic, Railway,
  Bridge, and other Engineering Works, &c. By WILLIAM HUMBER,
  A-M.Inst.C.E., &c. Imp. 4to, with 36 Double Plates, drawn to
  a large scale, Photographic Portrait of John Hawkshaw, C.E.,
  F.R.S., &c., and copious descriptive Letterpress, Specifications,
  &c., £3 3_s._ half-morocco.

_List of the Plates and Diagrams._

  Victoria Station and Roof, L. B. & S. C. R. (3 plates); Southport
  Pier (2 plates); Victoria Station and Roof, L. C. & D. and G. W.
  R. (6 plates); Roof of Cremorne Music Hall; Bridge over G. N.
  Railway; Roof of Station, Dutch Rhenish Rail (2 plates); Bridge
  over the Thames, West London Extension Railway (5 plates); Armour
  Plates: Suspension Bridge, Thames (4 plates); The Allen Engine;
  Suspension Bridge, Avon (3 plates); Underground Railway (3
  plates).

  "Handsomely lithographed and printed. It will find favour with
  many who desire to preserve in a permanent form copies of the
  plans and specifications prepared for the guidance of the
  contractors for many important engineering works."--_Engineer._


  _HUMBER'S PROGRESS OF MODERN ENGINEERING._ SECOND SERIES. Imp.
  4to, with 36 Double Plates, Photographic Portrait of Robert
  Stephenson, C.E., M.P., F.R.S., &c., and copious descriptive
  Letterpress, Specifications, &c., £3 3_s._ half-morocco.

_List of the Plates and Diagrams._

  Birkenhead Docks, Low Water Basin (15 plates); Charing Cross
  Station Roof, C. C. Railway (3 plates); Digswell Viaduct,
  Great Northern Railway; Robbery Wood Viaduct, Great Northern
  Railway; Iron Permanent Way; Clydach Viaduct, Merthyr, Tredegar,
  and Abergavenny Railway; Ebbw Viaduct, Merthyr, Tredegar, and
  Abergavenny Railway; College Wood Viaduct, Cornwall Railway;
  Dublin Winter Palace Roof (3 plates); Bridge over the Thames, L.
  C. & D. Railway (6 plates); Albert Harbour, Greenock (4 plates).

  "Mr. Humber has done the profession good and true service, by
  the fine collection of examples he has here brought before the
  profession and the public."--_Practical Mechanic's Journal._


  _HUMBER'S PROGRESS OF MODERN ENGINEERING._ THIRD SERIES.
  Imp. 4to, with 40 Double Plates, Photographic Portrait of J.
  R. M'Clean, late Pres. Inst. C.E., and copious descriptive
  Letterpress, Specifications, &c., £3 3_s._ half-morocco.

_List of the Plates and Diagrams._

  MAIN DRAINAGE, METROPOLIS.--_North Side._--Map showing
  Interception of Sewers; Middle Level Sewer (2 plates); Outfall
  Sewer, Bridge over River Lea (3 plates); Outfall Sewer, Bridge
  over Marsh Lane, North Woolwich Railway, and Bow and Barking
  Railway Junction; Outfall Sewer, Bridge over Bow and Barking
  Railway (3 plates); Outfall Sewer, Bridge over East London
  Waterworks' Feeder (2 plates); Outfall Sewer, Reservoir (2
  plates); Outfall Sewer, Tumbling Bay and Outlet; Outfall Sewer,
  Penstocks. _South Side._--Outfall Sewer, Bermondsey Branch (2
  plates); Outfall Sewer, Reservoir and Outlet (4 plates); Outfall
  Sewer, Filth Hoist; Sections of Sewers (North and South Sides).

  THAMES EMBANKMENT.--Section of River Wall; Steamboat Pier,
  Westminster (2 plates); Landing Stairs between Charing Cross and
  Waterloo Bridges; York Gate (2 plates); Overflow and Outlet at
  Savoy Street Sewer (3 plates); Steamboat Pier, Waterloo Bridge (3
  plates); Junction of Sewers, Plans and Sections; Gullies, Plans
  and Sections; Rolling Stock; Granite and Iron Forts.

  "The drawings have a constantly increasing value, and whoever
  desires to possess clear representations of the two great works
  carried out by our Metropolitan Board will obtain Mr. Humber's
  volume."--_Engineer._


  _HUMBER'S PROGRESS OF MODERN ENGINEERING._ FOURTH SERIES. Imp.
  4to, with 36 Double Plates, Photographic Portrait of John Fowler,
  late Pres. Inst. C.E., and copious descriptive Letterpress,
  Specifications, &c., £3 3_s._ half-morocco.

_List of the Plates and Diagrams._

  Abbey Mills Pumping Station, Main Drainage, Metropolis (4
  plates); Barrow Docks (5 plates); Manquis Viaduct, Santiago and
  Valparaiso Railway (2 plates); Adams Locomotive, St. Helen's
  Canal Railway (2 plates); Cannon Street Station Roof, Charing
  Cross Railway (3 plates); Road Bridge over the River Moka (2
  plates); Telegraphic Apparatus for Mesopotamia; Viaduct over
  the River Wye, Midland Railway (3 plates); St. Germans Viaduct,
  Cornwall Railway (2 plates); Wrought-Iron Cylinder for Diving
  Bell; Millwall Docks (6 plates); Milroy's Patent Excavator;
  Metropolitan District Railway (6 plates); Harbours, Ports, and
  Breakwaters (3 plates).

  "We gladly welcome another year's issue of this valuable
  publication from the able pen of Mr. Humber. The accuracy and
  general excellence of this work are well known, while its
  usefulness in giving the measurements and details of some of
  the latest examples of engineering, as carried out by the
  most eminent men in the profession, cannot be too highly
  prized."--_Artisan._


_=Statics, Graphic and Analytic.=_

  _GRAPHIC AND ANALYTIC STATICS, in their Practical Application
  to the Treatment of Stresses in Roofs, Solid Girders, Lattice,
  Bowstring and Suspension Bridges, Braced Iron Arches and Piers,
  and other Frameworks._ By R. HUDSON GRAHAM, C.E. Containing
  Diagrams and Plates to Scale. With numerous Examples, many taken
  from existing Structures. Specially arranged for Class-work in
  Colleges and Universities. Second Edition, Revised and Enlarged.
  8vo, 16_s._ cloth.

  "Mr. Graham's book will find a place wherever graphic and
  analytic statics are used or studied."--_Engineer._

  "The work is excellent from a practical point of view, and
  has evidently been prepared with much care. The directions
  for working are ample, and are illustrated by an abundance of
  well-selected examples. It is an excellent text-book for the
  practical draughtsman."--_Athenæum._


_=Practical Mathematics.=_

  _MATHEMATICS FOR PRACTICAL MEN_: Being a Commonplace Book of Pure
  and Mixed Mathematics. Designed chiefly for the use of Civil
  Engineers, Architects and Surveyors. By OLINTHUS GREGORY, L.L.D.,
  F.R.A.S., Enlarged by HENRY LAW, C.E. 4th Edition, carefully
  Revised by J. R. YOUNG, formerly Professor of Mathematics,
  Belfast College. With 13 Plates. 8vo, £1 1_s._ cloth.

  "The engineer or architect will here find ready to his hand rules
  for solving nearly every mathematical difficulty that may arise
  in his practice. The rules are in all cases explained by means of
  examples, in which every step of the process is clearly worked
  out."--_Builder._

  "One of the most serviceable books for practical mechanics....
  It is an instructive book for the student, and a text-book for
  him who, having once mastered the subjects it treats of, needs
  occasionally to refresh his memory upon them."--_Building News._


_=Hydraulic Tables.=_

  _HYDRAULIC TABLES, CO-EFFICIENTS, and FORMULÆ for finding the
  Discharge of Water from Orifices, Notches, Weirs, Pipes, and
  Rivers._ With New Formulæ, Tables, and General Information on
  Rainfall, Catchment-Basins, Drainage, Sewerage, Water Supply for
  Towns and Mill Power. By JOHN NEVILLE, Civil Engineer, M.R.I.A.
  Third Ed., carefully Revised, with considerable Additions.
  Numerous Illusts. Cr. 8vo, 14_s._ cloth.

  "Alike valuable to students and engineers in practice; its study
  will prevent the annoyance of avoidable failures, and assist
  them to select the readiest means of successfully carrying out
  any given work connected with hydraulic engineering."--_Mining
  Journal._

  "It is, of all English books on the subject, the one nearest
  to completeness.... From the good arrangement of the matter,
  the clear explanations, and abundance of formulæ, the carefully
  calculated tables, and, above all, the thorough acquaintance with
  both theory and construction, which is displayed from first to
  last, the book will be found to be an acquisition."--_Architect._


_=Hydraulics.=_

  _HYDRAULIC MANUAL._ Consisting of Working Tables and Explanatory
  Text. Intended as a Guide in Hydraulic Calculations and Field
  Operations. By LOWIS D'A. JACKSON, Author of "Aid to Survey
  Practice," "Modern Metrology," &c. Fourth Edition, Enlarged.
  Large cr. 8vo, 16_s._ cl.

  "The author has had a wide experience in hydraulic engineering
  and has been a careful observer of the facts which have come
  under his notice, and from the great mass of material at his
  command he has constructed a manual which may be accepted as a
  trustworthy guide to this branch of the engineer's profession.
  We can heartily recommend this volume to all who desire to
  be acquainted with the latest development of this important
  subject."--_Engineering._

  "The standard-work in this department of mechanics."--_Scotsman._

  "The most useful feature of this work is its freedom from what is
  superannuated, and its thorough adoption of recent experiments;
  the text is, in fact, in great part a short account of the great
  modern experiments."--_Nature._


_=Drainage.=_

  _ON THE DRAINAGE OF LANDS, TOWNS, AND BUILDINGS._ By G. D.
  DEMPSEY, C.E., Author of "The Practical Railway Engineer," &c.
  Revised, with large Additions on RECENT PRACTICE IN DRAINAGE
  ENGINEERING, by D. KINNEAR CLARK, M.Inst.C.E. Author of
  "Tramways: Their Construction and Working," "A Manual of Rules,
  Tables, and Data for Mechanical Engineers," &c. Second Edition,
  Corrected. Fcap. 8vo, 5_s._ cloth.

  "The new matter added to Mr. Dempsey's excellent work is
  characterised by the comprehensive grasp and accuracy of
  detail for which the name of Mr. D. K. Clark is a sufficient
  voucher."--_Athenæum._

  "As a work on recent practice in drainage engineering, the
  book is to be commended to all who are making that branch of
  engineering science their special study."--_Iron._

  "A comprehensive manual on drainage engineering, and a useful
  introduction to the student."--_Building News._


_=Water Storage, Conveyance, and Utilisation.=_

  _WATER ENGINEERING_: A Practical Treatise on the Measurement,
  Storage, Conveyance, and Utilisation of Water for the Supply of
  Towns, for Mill Power, and for other Purposes. By CHARLES SLAGG,
  Water and Drainage Engineer, A.M.Inst.C.E., Author of "Sanitary
  Work in the Smaller Towns, and in Villages," &c. With numerous
  Illusts. Cr. 8vo. 7_s._ 6_d._ cloth.

  "As a small practical treatise on the water supply of towns, and
  on some applications of water-power, the work is in many respects
  excellent."--_Engineering._

  "The author has collated the results deduced from the experiments
  of the most eminent authorities, and has presented them in
  a compact and practical form, accompanied by very clear and
  detailed explanations.... The application of water as a motive
  power is treated very carefully and exhaustively."--_Builder._

  "For anyone who desires to begin the study of hydraulics with a
  consideration of the practical applications of the science there
  is no better guide."--_Architect._


_=River Engineering.=_

  _RIVER BARS: The Causes of their Formation, and their Treatment
  by "Induced Tidal Scour;"_ with a Description of the Successful
  Reduction by this Method of the Bar at Dublin. By I. J. MANN,
  Assist. Eng. to the Dublin Port and Docks Board. Royal 8vo, 7_s._
  6_d._ cloth.

  "We recommend all interested in harbour works--and, indeed,
  those concerned in the improvements of rivers generally--to
  read Mr. Mann's interesting work on the treatment of river
  bars."--_Engineer._


_=Trusses.=_

  _TRUSSES OF WOOD AND IRON. Practical Applications of Science
  in Determining the Stresses, Breaking Weights, Safe Loads,
  Scantlings, and Details of Construction_, with Complete Working
  Drawings. By WILLIAM GRIFFITHS, Surveyor, Assistant Master,
  Tranmere School of Science and Art. Oblong 8vo, 4_s._ 6_d._ cloth.

  "This handy little book enters so minutely into every detail
  connected with the construction of roof trusses, that no student
  need be ignorant of these matters."--_Practical Engineer._


_=Railway Working.=_

  _SAFE RAILWAY WORKING. A Treatise on Railway Accidents: Their
  Cause and Prevention; with a Description of Modern Appliances
  and Systems._ By CLEMENT E. STRETTON, C.E., Vice-President and
  Consulting Engineer, Amalgamated Society of Railway Servants.
  With Illustrations and Coloured Plates. Third Edition, Enlarged.
  Crown 8vo, 3_s._ 6_d._ cloth.

  "A book for the engineer, the directors, the managers; and, in
  short, all who wish for information on railway matters will find
  a perfect encyclopædia in 'Safe Railway Working.'"--_Railway
  Review._

  "We commend the remarks on railway signalling to all railway
  managers, especially where a uniform code and practice is
  advocated."--_Herepath's Railway Journal._

  "The author may be congratulated on having collected, in a very
  convenient form, much valuable information on the principal
  questions affecting the safe working of railways."--_Railway
  Engineer._


_=Oblique Bridges.=_

  _A PRACTICAL AND THEORETICAL ESSAY ON OBLIQUE BRIDGES._ With 13
  large Plates. By the late GEORGE WATSON BUCK, M.I.C.E. Third
  Edition, revised by his Son, J. H. WATSON BUCK, M.I.C.E.; and
  with the addition of Description to Diagrams for Facilitating the
  Construction of Oblique Bridges, by W. H. BARLOW, M.I.C.E. Royal
  8vo, 12_s._ cloth.

  "The standard text-book for all engineers regarding skew arches
  is Mr. Buck's treatise, and it would be impossible to consult a
  better."--_Engineer._

  "Mr. Buck's treatise is recognised as a standard text-book, and
  his treatment has divested the subject of many of the intricacies
  supposed to belong to it. As a guide to the engineer and
  architect, on a confessedly difficult subject, Mr. Buck's work is
  unsurpassed."--_Building News._


_=Tunnel Shafts.=_

  _THE CONSTRUCTION OF LARGE TUNNEL SHAFTS: A Practical and
  Theoretical Essay._ By J. H. WATSON BUCK, M.Inst.C.E., Resident
  Engineer, London and North-Western Railway. Illustrated with
  Folding Plates. Royal 8vo, 12_s._ cloth.

  "Many of the methods given are of extreme practical value to the
  mason; and the observations on the form of arch, the rules for
  ordering the stone, and the construction of the templates will be
  found of considerable use. We commend the book to the engineering
  profession."--_Building News._

  "Will be regarded by civil engineers as of the utmost
  value, and calculated to save much time and obviate many
  mistakes."--_Colliery Guardian._


_=Student's Text-Book on Surveying.=_

  _PRACTICAL SURVEYING_: A Text-Book for Students preparing for
  Examination or for Survey-work in the Colonies. By GEORGE W.
  USILL, A.M.I.C.E., Author of "The Statistics of the Water Supply
  of Great Britain." With Four Lithographic Plates and upwards of
  330 Illustrations. Third Edition, Revised and Enlarged. Including
  Tables of Natural Sines, Tangents, Secants, &c. Crown 8vo, 7_s._
  6_d._ cloth; or, on THIN PAPER, bound in limp leather, gilt
  edges, rounded corners, for pocket use, 12_s._ 6_d._

  "The best forms of instruments are described as to their
  construction, uses and modes of employment, and there are
  innumerable hints on work and equipment such as the author, in
  his experience as surveyor, draughtsman, and teacher, has found
  necessary, and which the student in his inexperience will find
  most serviceable."--_Engineer._

  "The latest treatise in the English language on surveying, and
  we have no hesitation in saying that the student will find it
  a better guide than any of its predecessors.... Deserves to be
  recognised as the first book which should be put in the hands of
  a pupil of Civil Engineering, and every gentleman of education
  who sets out for the Colonies would find it well to have a
  copy."--_Architect._


_=Survey Practice.=_

  _AID TO SURVEY PRACTICE, for Reference in Surveying, Levelling,
  and Setting-out; and in Route Surveys of Travellers by Land
  and Sea._ With Tables, Illustrations, and Records. By LOWIS
  D'A. JACKSON, A.M.I.C.E., Author of "Hydraulic Manual," "Modern
  Metrology," &c. Second Edition, Enlarged. Large crown 8vo, 12_s._
  6d. cloth.

  "A valuable _vade-mecum_ for the surveyor. We can recommend this
  book as containing an admirable supplement to the teaching of the
  accomplished surveyor."--_Athenæum._

  "As a text-book we should advise all surveyors to place it in
  their libraries, and study well the matured instructions afforded
  in its pages."--_Colliery Guardian._

  "The author brings to his work a fortunate union of theory and
  practical experience which, aided by a clear and lucid style of
  writing, renders the book a very useful one."--_Builder._


_=Surveying, Land and Marine.=_

  _LAND AND MARINE SURVEYING_, in Reference to the Preparation
  of Plans for Roads and Railways; Canals, Rivers, Towns' Water
  Supplies; Docks and Harbours. With Description and Use of
  Surveying Instruments. By W. D. HASKOLL, C.E., Author of "Bridge
  and Viaduct Construction," &c. Second Edition, Revised, with
  Additions. Large cr. 8vo, 9_s._ cl.

  "This book must prove of great value to the student. We have no
  hesitation in recommending it, feeling assured that it will more
  than repay a careful study."--_Mechanical World._

  "A most useful and well arranged book. We can strongly recommend
  it as a carefully-written and valuable text-book. It enjoys a
  well-deserved repute among surveyors."--_Builder._

  "This volume cannot fail to prove of the utmost practical
  utility. It may be safely recommended to all students who aspire
  to become clean and expert surveyors."--_Mining Journal._


_=Field-Book for Engineers.=_

  _THE ENGINEER'S, MINING SURVEYOR'S, AND CONTRACTOR'S FIELD-BOOK._
  Consisting of a Series of Tables, with Rules, Explanations
  of Systems, and use of Theodolite for Traverse Surveying and
  Plotting the Work with minute accuracy by means of Straight
  Edge and Set Square only; Levelling with the Theodolite,
  Casting-out and Reducing Levels to Datum, and Plotting
  Sections in the ordinary manner; setting-out Curves with the
  Theodolite by Tangential Angles and Multiples, with Right
  and Left-hand Readings of the Instrument: Setting-out Curves
  without Theodolite, on the System of Tangential Angles by sets
  of Tangents and Offsets; and Earthwork Tables to 80 feet deep,
  calculated for every 6 inches in depth. By W. D. HASKOLL, C.E.
  Fourth Edition. Crown 8vo, 12_s._ cloth.

  "The book is very handy; the separate tables of sines and
  tangents to every minute will make it useful for many other
  purposes, the genuine traverse tables existing all the
  same."--_Athenæum._

  "Every person engaged in engineering field operations will
  estimate the importance of such a work and the amount of valuable
  time which will be saved by reference to a set of reliable tables
  prepared with the accuracy and fulness of those given in this
  volume."--_Railway News._


_=Levelling.=_

  _A TREATISE ON THE PRINCIPLES AND PRACTICE OF LEVELLING._ Showing
  its Application to purposes of Railway and Civil Engineering, in
  the Construction of Roads; with Mr. TELFORD'S Rules for the same.
  By FREDERICK W. SIMMS, F.G.S., M.Inst.C.E. Seventh Edition, with
  the addition of Law's Practical Examples for Setting-out Railway
  Curves, and TRAUTWINE'S Field Practice of Laying-out Circular
  Curves. With 7 Plates and numerous Woodcuts. 8vo, 8_s._ 6_d._
  cloth. *** TRAUTWINE on Curves may be had separate, 5_s._

  "The text-book on levelling in most of our engineering schools
  and colleges."--_Engineer._

  "The publishers have rendered a substantial service to the
  profession, especially to the younger members, by bringing out
  the present edition of Mr. Simms's useful work.--_Engineering._


_=Trigonometrical Surveying.=_

  _AN OUTLINE OF THE METHOD OF CONDUCTING A TRIGONOMETRICAL SURVEY,
  for the Formation of Geographical and Topographical Maps and
  Plans, Military Reconnaissance, Levelling, &c._, with Useful
  Problems, Formulæ, and Tables. By Lieut.-General FROME, R.E.
  Fourth Edition, Revised and partly Re-written by Major-General
  Sir CHARLES WARREN, G.C.M.G., R.E. With 19 Plates and 115
  Woodcuts. Royal 8vo, 16_s._ cloth.

  "The simple fact that a fourth edition has been called for is
  the best testimony to its merits. No words of praise from us can
  strengthen the position so well and so steadily maintained by
  this work. Sir Charles Warren has revised the entire work, and
  made such additions as were necessary to bring every portion of
  the contents up to the present date."--_Broad Arrow._


_=Field Fortification.=_

  _A TREATISE ON FIELD FORTIFICATION, THE ATTACK OF FORTRESSES,
  MILITARY MINING, AND RECONNOITRING._ By Colonel I. S. MACAULAY,
  late Professor of Fortification in the R.M.A., Woolwich. Sixth
  Edition. Crown 8vo, with separate Atlas of 12 Plates, 12_s._
  cloth.


_=Tunnelling.=_

  _PRACTICAL TUNNELLING._ Explaining in detail the Setting-out of
  the works, Shaft-sinking and Heading-driving, Ranging the Lines
  and Levelling underground, Sub-Excavating, Timbering, and the
  Construction of the Brickwork of Tunnels, with the amount of
  Labour required for, and the Cost of, the various portions of the
  work. By FREDERICK W. SIMMS, F.G.S., M.Inst.C.E. Third Edition,
  Revised and Extended by D. KINNEAR CLARK, M.Inst.C.E. Imperial
  8vo, with 21 Folding Plates and numerous Wood Engravings, 30_s._
  cloth.

  "The estimation in which Mr. Simms's book on tunnelling has been
  held for over thirty years cannot be more truly expressed than
  in the words of the late Prof. Rankine:--'The best source of
  information on the subject of tunnels is Mr. F. W. Simms's work
  on Practical Tunnelling.'"--_Architect._

  "It has been regarded from the first as a text-book of the
  subject.... Mr. Clark has added immensely to the value of the
  book."--_Engineer._


_=Tramways and their Working.=_

  _TRAMWAYS: THEIR CONSTRUCTION AND WORKING._ Embracing a
  Comprehensive History of the System; with an exhaustive Analysis
  of the various Modes of Traction, including Horse-Power, Steam,
  Cable Traction, Electric Traction, &c.; a Description of the
  Varieties of Rolling Stock; and ample Details of Cost and Working
  Expenses. New Edition, Thoroughly Revised, and Including the
  Progress recently made in Tramway Construction, &c. &c. By D.
  KINNEAR CLARK, M.Inst.C.E. With numerous Illustrations and
  Folding Plates. In One Volume, 8vo, 700 pages, price about 25_s._

  [_Nearly ready._

  "All interested in tramways must refer to it, as all
  railway engineers have turned to the author's work 'Railway
  Machinery.'"--_Engineer._

  "An exhaustive and practical work on tramways, in which the
  history of this kind of locomotion, and a description and
  cost of the various modes of laying tramways, are to be
  found."--_Building News._

  "The best form of rails, the best mode of construction, and the
  best mechanical appliances are so fairly indicated in the work
  under review, that any engineer about to construct a tramway will
  be enabled at once to obtain the practical information which will
  be of most service to him."--_Athenæum._


_=Curves, Tables for Setting-out.=_

  _TABLES OF TANGENTIAL ANGLES AND MULTIPLES for Setting-out
  Curves from 5 to 200 Radius._ By ALEXANDER BEAZELEY, M.Inst.C.E.
  Fourth Edition. Printed on 48 Cards, and sold in a cloth box,
  waistcoat-pocket size, 3_s._ 6_d._

  "Each table is printed on a small card, which, being placed
  on the theodolite, leaves the hands free to manipulate the
  instrument--no small advantage as regards the rapidity of
  work."--_Engineer._

  "Very handy; a man may know that all his day's work must fall on
  two of these cards, which he puts into his own card-case, and
  leaves the rest behind."--_Athenæum._


_=Earthwork.=_

  _EARTHWORK TABLES._ Showing the Contents in Cubic Yards of
  Embankments, Cuttings, &c., of Heights or Depths up to an average
  of 80 feet. By JOSEPH BROADBENT, C.E., and FRANCIS CAMPIN, C.E.
  Crown 8vo, 5_s._ cloth.

  "The way in which accuracy is attained, by a simple division of
  each cross section into three elements, two in which are constant
  and one variable, is ingenious."--_Athenæum._


_=Heat, Expansion by.=_

  _EXPANSION OF STRUCTURES BY HEAT._ By JOHN KEILY, C.E., late of
  the Indian Public Works and Victorian Railway Departments. Crown
  8vo, 3_s._ 6_d._ cloth.

SUMMARY OF CONTENTS.

  Section    I.  FORMULAS AND DATA.
  Section   II.  METAL BARS.
  Section  III.  SIMPLE FRAMES.
  Section   IV.  COMPLEX FRAMES AND PLATES.
  Section    V.  THERMAL CONDUCTIVITY.
  Section   VI.  MECHANICAL FORCE OF HEAT.
  Section  VII.  WORK OF EXPANSION AND CONTRACTION.
  Section VIII.  SUSPENSION BRIDGES.
  Section   IX.  MASONRY STRUCTURES.

  "The aim the author has set before him, viz., to show the effects
  of heat upon metallic and other structures, is a laudable one,
  for this is a branch of physics upon which the engineer or
  architect can find but little reliable and comprehensive data in
  books."--_Builder._

  "Whoever is concerned to know the effect of changes of
  temperature on such structures as suspension bridges and the
  like, could not do better than consult Mr. Keily's valuable and
  handy exposition of the geometrical principles involved in these
  changes."--_Scotsman._


_=Earthwork, Measurement of.=_

  _A MANUAL ON EARTHWORK._ By ALEX. J. S. GRAHAM, C.E. With
  numerous Diagrams. Second Edition. 18mo, 2_s._ 6_d._ cloth.

  "A great amount of practical information, very admirably
  arranged, and available for rough estimates, as well as for
  the more exact calculations required in the engineer's and
  contractor's offices."--_Artizan._


_=Strains in Ironwork.=_

  _THE STRAINS ON STRUCTURES OF IRONWORK_: with Practical Remarks
  on Iron Construction. By F. W. SHEILDS, M.Inst.C.E. Second
  Edition, with 5 Plates. Royal 8vo, 5_s._ cloth.

  "The student cannot find a better little book on this
  subject."--_Engineer._


_=Cast Iron and other Metals, Strength of.=_

  _A PRACTICAL ESSAY ON THE STRENGTH OF CAST IRON AND OTHER
  METALS._ By THOMAS TREDGOLD, C.E. Fifth Edition, including
  Hodgkinson's Experimental Researches. 8vo, 12_s._ cloth.


_=Oblique Arches.=_

  _A PRACTICAL TREATISE ON THE CONSTRUCTION OF OBLIQUE ARCHES._ By
  JOHN HART. Third Edition, with Plates. Imperial 8vo, 8_s._ cloth.


_=Girders, Strength of.=_

  _GRAPHIC TABLE FOR FACILITATING THE COMPUTATION OF THE WEIGHTS
  OF WROUGHT IRON AND STEEL GIRDERS, etc._, for Parliamentary and
  other Estimates. By J. H. WATSON BUCK, M.Inst.C.E. On a Sheet,
  2_s._ 6_d._


_=Water Supply and Water-Works.=_

  _A PRACTICAL TREATISE ON THE WATER SUPPLY OF TOWNS AND THE
  CONSTRUCTION OF WATER-WORKS._ By W. K. BURTON, A.M.Inst.C E.,
  Professor of Sanitary Engineering in the Imperial University,
  Tokyo, Japan, and Consulting Engineer to the Tokyo Water-Works.
  With an Appendix on =Water-Works in Countries subject to
  Earthquakes=, by JOHN MILNE, F.R.S., Professor of Mining in the
  Imperial University of Japan. With numerous Plates and Illusts.

  [_In the press._


MARINE ENGINEERING, SHIPBUILDING, NAVIGATION, etc.


_=Pocket-Book for Naval Architects and Shipbuilders.=_

  _THE NAVAL ARCHITECT'S AND SHIPBUILDER'S POCKET-BOOK of Formulæ,
  Rules, and Tables, and MARINE ENGINEER'S AND SURVEYOR'S Handy
  Book of Reference._ By CLEMENT MACKROW, Member of the Institution
  of Naval Architects, Naval Draughtsman. Fifth Edition, Revised
  and Enlarged to 700 pages, with upwards of 300 Illustrations.
  Fcap., 12_s._ 6_d._ strongly bound in leather.

SUMMARY OF CONTENTS.

SIGNS AND SYMBOLS, DECIMAL FRACTIONS.--TRIGONOMETRY.--PRACTICAL
GEOMETRY.--MENSURATION.--CENTRES AND MOMENTS OF FIGURES.--MOMENTS
OF INERTIA AND RADII OF GYRATION.--ALGEBRAICAL EXPRESSIONS FOR
SIMPSON'S RULES.--MECHANICAL PRINCIPLES.--CENTRE OF GRAVITY.--LAWS
OF MOTION.--DISPLACEMENT, CENTRE OF BUOYANCY.--CENTRE OF
GRAVITY OF SHIP'S HULL.--STABILITY CURVES AND METACENTRES.--SEA
AND SHALLOW-WATER WAVES.--ROLLING OF SHIPS.--PROPULSION AND
RESISTANCE OF VESSELS.--SPEED TRIALS.--SAILING, CENTRE OF
EFFORT.--DISTANCES DOWN RIVERS, COAST LINES.--STEERING AND RUDDERS
OF VESSELS.--LAUNCHING CALCULATIONS AND VELOCITIES.--WEIGHT
OF MATERIAL AND GEAR.--GUN PARTICULARS AND WEIGHT.--STANDARD
GAUGES.--RIVETED JOINTS AND RIVETING.--STRENGTH AND TESTS OF
MATERIALS.--BINDING AND SHEARING STRESSES, ETC.--STRENGTH OF
SHAFTING, PILLARS, WHEELS, ETC.--HYDRAULIC DATA, ETC.--CONIC
SECTIONS, CATENARIAN CURVES.--MECHANICAL POWERS, WORK.--BOARD
OF TRADE REGULATIONS FOR BOILERS AND ENGINES.--BOARD OF TRADE
REGULATIONS FOR SHIPS.--LLOYD'S RULES FOR BOILERS.--LLOYD'S
WEIGHT OF CHAINS.--LLOYD'S SCANTLINGS FOR SHIPS.--DATA OF ENGINES
AND VESSELS.--SHIPS' FITTINGS AND TESTS.--SEASONING PRESERVING
TIMBER.--MEASUREMENT OF TIMBER.--ALLOYS, PAINTS, VARNISHES.--DATA
FOR STOWAGE.--ADMIRALTY TRANSPORT REGULATIONS.--RULES
FOR HORSEPOWER, SCREW PROPELLERS, ETC.--PERCENTAGES FOR
BUTT STRAPS, ETC.--PARTICULARS OF YACHTS.--MASTING AND
RIGGING VESSELS.--DISTANCES OF FOREIGN PORTS.--TONNAGE
TABLES.--VOCABULARY OF FRENCH AND ENGLISH TERMS.--ENGLISH
WEIGHTS AND MEASURES.--FOREIGN WEIGHTS AND MEASURES.--DECIMAL
EQUIVALENTS.--FOREIGN MONEY.--DISCOUNT AND WAGE TABLES.--USEFUL
NUMBERS AND READY RECKONERS--TABLES OF CIRCULAR MEASURES.--TABLES
OF AREAS OF AND CIRCUMFERENCES OF CIRCLES.--TABLES OF AREAS OF
SEGMENTS OF CIRCLES.--TABLES OF SQUARES AND CUBES AND ROOTS OF
NUMBERS.--TABLES OF LOGARITHMS OF NUMBERS.--TABLES OF HYPERBOLIC
LOGARITHMS.--TABLES OF NATURAL SINES, TANGENTS, ETC.--TABLES OF
LOGARITHMIC SINES, TANGENTS, ETC.

  "In these days of advanced knowledge a work like this is of
  the greatest value. It contains a vast amount of information.
  We unhesitatingly say that it is the most valuable compilation
  for its specific purpose that has ever been printed. No
  naval architect, engineer, surveyor, or seaman, wood or iron
  shipbuilder, can afford to be without this work."--_Nautical
  Magazine._

  "Should be used by all who are engaged in the construction or
  designs of vessels.... Will be found to contain the most useful
  tables and formulæ required by shipbuilders, carefully collected
  from the best authorities, and put together in a popular and
  simple form."--_Engineer._

  "The professional shipbuilder has now, in a convenient and
  accessible form, reliable data for solving many of the
  numerous problems that present themselves in the course of his
  work."--_Iron._

  "There is no doubt that a pocket-book of this description must be
  a necessity in the shipbuilding trade.... The volume contains a
  mass of useful information clearly expressed and presented in a
  handy form."--_Marine Engineer._


_=Marine Engineering.=_

  _MARINE ENGINES AND STEAM VESSELS (A Treatise on)._ By
  ROBERT MURRAY, C.E. Eighth Edition, thoroughly Revised, with
  considerable Additions by the Author and by GEORGE CARLISLE,
  C.E., Senior Surveyor to the Board of Trade at Liverpool. 12mo,
  5_s._ cloth boards.

  "Well adapted to give the young steamship engineer or marine
  engine and boiler maker a general introduction into his practical
  work."--_Mechanical World._

  "We feel sure that this thoroughly revised edition will continue
  to be as popular in the future as it has been in the past, as,
  for its size, it contains more useful information than any
  similar treatise."--_Industries._

  "As a compendious and useful guide to engineers of our
  mercantile and royal naval services, we should say it cannot be
  surpassed."--_Building News._

  "The information given is both sound and sensible, and well
  qualified to direct young sea-going hands on the straight road
  to the extra chief's certificate.... Most useful to surveyors,
  inspectors, draughtsmen, and young engineers."--_Glasgow Herald._


_=Pocket-Book for Marine Engineers.=_

  _A POCKET-BOOK OF USEFUL TABLES AND FORMULÆ FOR MARINE
  ENGINEERS._ By FRANK PROCTOR, A.I.N.A, Third Edition. Royal 32mo,
  leather, gilt edges, with strap, 4_s._

  "We recommend it to our readers as going far to supply a
  long-felt want."--_Naval Science._

  "A most useful companion to all marine engineers."--_United
  Service Gazette._


_=Introduction to Marine Engineering.=_

  _ELEMENTARY ENGINEERING: A Manual for Young Marine Engineers and
  Apprentices._ In the Form of Questions and Answers on Metals,
  Alloys, Strength of Materials, Construction and Management of
  Marine Engines and Boilers, Geometry, &c. &c. With an Appendix
  of Useful Tables. By JOHN SHERREN BREWER, Government Marine
  Surveyor, Hong-Kong. Second Edition, Revised. Small crown 8vo,
  2_s._ cloth.

  "Contains much valuable information for the class for whom it is
  intended, especially in the chapters on the management of boilers
  and engines."--_Nautical Magazine._

  "A useful introduction to the more elaborate
  text-books."--_Scotsman._

  "To a student who has the requisite desire and resolve to
  attain a thorough knowledge, Mr. Brewer offers decidedly useful
  help."--_Athenæum._


_=Navigation.=_

  _PRACTICAL NAVIGATION._ Consisting of THE SAILOR'S SEA-BOOK, by
  JAMES GREENWOOD and W. H. ROSSER; together with the requisite
  Mathematical and Nautical Tables for the Working of the Problems,
  by HENRY LAW, C.E., and Professor J. R. YOUNG. Illustrated. 12mo,
  7_s._ strongly half-bound.


_=Drawing for Marine Engineers.=_

  _LOCKIE'S MARINE ENGINEER'S DRAWING-BOOK._ Adapted to the
  Requirements of the Board of Trade Examinations. By JOHN LOCKIE,
  C.E. With 22 Plates, Drawn to Scale. Royal 3vo, 3_s._ 6_d._ cloth.

  "The student who learns from these drawings will have nothing to
  unlearn."--_Engineer._

  "The examples chosen are essentially practical, and are such as
  should prove of service to engineers generally, while admirably
  fulfilling their specific purpose."--_Mechanical World._


_=Sailmaking.=_

  _THE ART AND SCIENCE OF SAILMAKING._ By SAMUEL B. SADLER.
  Practical Sailmaker, late in the employment of Messrs. Ratsey
  and Lapthorne, of Cowes and Gosport. With Plates and other
  Illustrations. Small 4to, 12_s._ 6_d._ cloth.

SUMMARY OF CONTENTS.

CHAP. I. THE MATERIALS USED AND THEIR RELATION TO SAILS.--II. ON
THE CENTRE OF EFFORT.--III. ON MEASURING.--IV. ON DRAWING.--V.
ON THE NUMBER OF CLOTHS REQUIRED.--VI. ON ALLOWANCES.--VII.
CALCULATION OF GORES.--VIII. ON CUTTING OUT.--IX. ON ROPING.--X. ON
DIAGONAL-CUT SAILS.--XI. CONCLUDING REMARKS.

  "This work is very ably written, and is illustrated by diagrams
  and carefully worked calculations. The work should be in the
  hands of every sailmaker, whether employer or employed, as it
  cannot fail to assist them in the pursuit of their important
  avocations."--_Isle of Wight Herald._

  "This extremely practical work gives a complete education in
  all the branches of the manufacture, cutting out, roping,
  seaming, and goring. It is copiously illustrated, and will form a
  first-rate text-book and guide."--_Portsmouth Times._

  "The author of this work has rendered a distinct service to all
  interested in the art of sailmaking. The subject of which he
  treats is a congenial one. Mr. Sadler is a practical sailmaker,
  and has devoted years of careful observation and study to the
  subject; and the results of the experience thus gained he has set
  forth in the volume before us."--_Steamship._


_=Chain Cables.=_

  _CHAIN CABLES AND CHAINS._ Comprising Sizes and Curves of Links,
  Studs, &c., Iron for Cables and Chains, Chain Cable and Chain
  Making, Forming and Welding Links, Strength of Cables and Chains,
  Certificates for Cables, Marking Cables, Prices of Chain Cables
  and Chains, Historical Notes, Acts of Parliament, Statutory
  Tests, Charges for Testing, List of Manufacturers of Cables,
  &c. &c. By THOMAS W. TRAILL, F.E.R.N., M. Inst. C.E., Engineer
  Surveyor in Chief, Board of Trade, Inspector of Chain Cable
  and Anchor Proving Establishments, and General Superintendent,
  Lloyd's Committee on Proving Establishments. With numerous
  Tables, Illustrations and Lithographic Drawings. Folio, £2 2_s._
  cloth, bevelled boards.

  "It contains a vast amount of valuable Information. Nothing
  seems to be wanting to make it a complete and standard work of
  reference on the subject."--_Nautical Magazine._


MINING AND METALLURGY.


_=Mining Machinery.=_

  _MACHINERY FOR METALLIFEROUS MINES_: A Practical Treatise for
  Mining Engineers, Metallurgists, and Managers of Mines. By E.
  HENRY DAVIES, M.E., F.G.S. Crown 8vo, 580 pp., with upwards of
  300 Illustrations, 12_s._ 6_d._ cloth.

  [_Just published._

  "Mr. Davies, in this handsome volume, has done the advanced
  student and the manager of mines good service. Almost every
  kind of machinery in actual use is carefully described, and the
  woodcuts and plates are good."--_Athenæum._

  "From cover to cover the work exhibits all the same
  characteristics which excite the confidence and attract the
  attention of the student as he peruses the first page. The work
  may safely be recommended. By its publication the literature
  connected with the industry will be enriched, and the reputation
  of its author enhanced."--_Mining Journal._

  "Mr. Davies has endeavoured to bring before his readers the best
  of everything in modern mining appliances. His work carries
  internal evidence of the author's impartiality, and this
  constitutes one of the great merits of the book. Throughout
  his work the criticisms are based on his own or other reliable
  experience."--_Iron and Steel Trades' Journal._

  "The work deals with nearly every class of machinery or
  apparatus likely to be met with or required in connection with
  metalliferous mining, and is one which we have every confidence
  in recommending."--_Practical Engineer._


_=Metalliferous Minerals and Mining.=_

  _A TREATISE ON METALLIFEROUS MINERALS AND MINING._ By D. C.
  DAVIES, F.G.S., Mining Engineer, &c., Author of "A Treatise on
  Slate and Slate Quarrying." Fifth Edition, thoroughly Revised and
  much Enlarged, by his Son, E. HENRY DAVIES, M.E., F.G.S. With
  about 150 Illustrations. Crown 8vo, 12_s._ 6_d._ cloth.

  "Neither the practical miner nor the general reader interested
  in mines can have a better book for his companion and his
  guide."--_Mining Journal._

  "We are doing our readers a service in calling their attention to
  this valuable work."--_Mining World._

  "A book that will not only be useful to the geologist, the
  practical miner, and the metallurgist, but also very interesting
  to the general public."--_Iron._

  "As a history of the present state of mining throughout the
  world this book has a real value, end it supplies an actual
  want."--_Athenæum._


_=Earthy Minerals and Mining.=_

  _A TREATISE ON EARTHY & OTHER MINERALS AND MINING._ By D. C.
  DAVIES, F.G.S., Author of "Metalliferous Minerals," &c. Third
  Edition, revised and Enlarged, by his Son, E. HENRY DAVIES, M.E.,
  F.G.S. With about 100 Illustrations. Crown 8vo, 12_s._ 6_d._
  cloth.

  "We do not remember to have met with any English work on mining
  matters that contains the same amount of information packed in
  equally convenient form."--_Academy._

  "We should be inclined to rank it as among the very best of
  the handy technical and trades manuals which have recently
  appeared."--_British Quarterly Review._


_=Metalliferous Mining in the United Kingdom.=_

  _BRITISH MINING: A Treatise on the History,Discovery, Practical
  Development, and Future Prospects of Metalliferous Mines in
  the United Kingdom._ By ROBERT HUNT, F.R.S., Editor of "Ure's
  Dictionary of Arts, Manufactures, and Mines," &c. Upwards of 950
  pp., with 230 Illustrations. Second Edition, Revised. Super-royal
  8vo, £2 2_s._ cloth.

  "One of the most valuable works of reference of modern times.
  Mr. Hunt, as Keeper of Mining Records of the United Kingdom, has
  had opportunities for such a task not enjoyed by anyone else,
  and has evidently made the most of them.... The language and
  style adopted are good, and the treatment of the various subjects
  laborious, conscientious, and scientific."--_Engineering._

  "The book is, in fact, a treasure-house of statistical
  information on mining subjects, and we know of no other work
  embodying so great a mass of matter of this kind. Were this the
  only merit of Mr. Hunt's volume, it would be sufficient to render
  it indispensable in the library of everyone interested in the
  development of the mining and metallurgical industries of this
  Country.--_Athenæum._

  "A mass of Information not elsewhere available, and of the
  greatest value to those who may be interested in our great
  mineral industries."--_Engineer._


_=Underground Pumping Machinery.=_

  _MINE DRAINAGE._ Being a Complete and Practical Treatise on
  Direct-Acting Underground Steam Pumping Machinery, with a
  Description of a large number of the best known Engines, their
  General Utility and the Special Sphere of their Action, the Mode
  of their Application, and their merits compared with other forms
  of Pumping Machinery. By STEPHEN MICHELL. 8vo, 15_s_. cloth.

  "Will be highly esteemed by colliery owners and lessees, mining
  engineers, and students generally who require to be acquainted
  with the best means of securing the drainage of mines. It is a
  most valuable work, and stands almost alone in the literature of
  steam pumping machinery."--_Colliery Guardian._

  "Much valuable Information is given, so that the book is
  thoroughly worthy of an extensive circulation amongst practical
  men and purchasers of machinery."'--_Mining Journal._


_=Prospecting for Gold and other Metals.=_

  _THE PROSPECTOR'S HANDBOOK_: A Guide for the Prospector and
  Traveller in Search of Metal-Bearing or other Valuable Minerals.
  By J. W. ANDERSON, M.A. (Camb.), F.R.G.S., Author of "Fiji and
  New Caledonia." Fifth Edition, thoroughly Revised and Enlarged.
  Small crown 8vo, 3_s._ 6_d._ cloth.

  "Will supply a much felt want, especially among Colonists, in
  whose way are so often thrown many mineralogical specimens the
  value of which it is difficult to determine."--_Engineer._

  "How to find commercial minerals, and how to identify them when
  they are found, are the leading points to which attention is
  directed. The author has managed to pack as much practical detail
  into his pages as would supply material for a book three times
  its size."--_Mining Journal._


_=Mining Notes and Formulæ.=_

  _NOTES AND FORMULÆ FOR MINING STUDENTS._ By JOHN HERMAN MERIVALE,
  M.A., Certificated Colliery Manager, Professor of Mining in the
  Durham College of Science, Newcastle-upon-Tyne. Third Edition,
  Revised and Enlarged. Small crown 8vo, 2_s._ 6_d._ cloth.

  "Invaluable to anyone who is working up for an examination on
  mining subjects."--_Iron and Coal Trades Review._

  "The author has done his work in an exceedingly creditable
  manner, and has produced a book that will be of service to
  students, and those who are practically engaged in mining
  operations."--_Engineer._


_=Handybook for Miners.=_

  _THE MINER'S HANDBOOK_: A Handybook of Reference on the Subjects
  of Mineral Deposits, Mining Operations, Ore Dressing, &c. For the
  Use of Students and others interested in Mining matters. Compiled
  by JOHN MILNE, F.R.S., Professor of Mining in the Imperial
  University of Japan. Square 18mo, 7_s._ 6_d._ cloth.

  [_Just published._

  "Professor Milne's handbook is sure to be received with favour by
  all connected with mining, and will be extremely popular among
  students."--_Athenæum._


_=Miners' and Metallurgists' Pocket-Book.=_

  _A POCKET-BOOK FOR MINERS AND METALLURGISTS._ Comprising Rules,
  Formulæ, Tables, and Notes, for Use in Field and Office Work. By
  F. DANVERS POWER, F.G.S., M.E. Fcap. 8vo, 9_s._ leather, gilt
  edges.

  "This excellent book is an admirable example of its kind, and
  ought to find a large sale amongst English-speaking prospectors
  and mining engineers."--_Engineering._

  "Miners and metallurgists will find in this work a useful
  vade-mecum containing a mass of rules, formulæ, tables, and
  various other information, the necessity for reference to which
  occurs in. their daily duties."--_Iron._


_=Mineral Surveying and Valuing.=_

  _THE MINERAL SURVEYOR AND VALUER'S COMPLETE GUIDE, comprising a
  Treatise on Improved Mining Surveying and the Valuation of Mining
  Properties, with New Traverse Tables._ By WM. LINTERN. Third
  Edition, Enlarged. 12mo, 4_s._ cloth.

  "Mr. Lintern's book forms a valuable and thoroughly trustworthy
  guide."--_Iron and Coal Trades Review._


_=Asbestos and its Uses.=_

  _ASBESTOS: Its Properties, Occurrence, and Uses._ With some
  Account of the Mines of Italy and Canada. By ROBERT H. JONES.
  With Eight Collotype Plates and other Illustrations. Crown 8vo,
  12_s._ 6_d._ cloth.

  "An interesting and invaluable work."--_Colliery Guardian._


_=Explosives.=_

  _A HANDBOOK ON MODERN EXPLOSIVES._ Being a Practical Treatise
  on the Manufacture and Application of Dynamite, Gun-Cotton,
  Nitro-Glycerine, and other Explosive Compounds. Including the
  Manufacture of Collodion-Cotton. By M. EISSLER, Mining Engineer
  and Metallurgical Chemist, Author of "The Metallurgy of Gold,"
  "The Metallurgy of Silver," &c. With about 100 Illusts. Crown
  8vo, 10_s._ 6_d._ cloth.

  "Useful not only to the miner, but also to officers of both
  services to whom blasting and the use of explosives generally may
  at any time become a necessary auxiliary."--_Nature._

  "A veritable mine of information on the subject of explosives
  employed for military, mining, and blasting purposes."--_Army and
  Navy Gazette._


_=Colliery Management.=_

  _THE COLLIERY MANAGER'S HANDBOOK_: A Comprehensive Treatise on
  the Laying-out and Working of Collieries, Designed as a Book of
  Reference for Colliery Managers, and for the Use of Coal-Mining
  Students preparing for First-class Certificates. By CALEB PAMELY,
  Mining Engineer and Surveyor; Member of the North of England
  Institute of Mining and Mechanical Engineers; and Member of the
  South Wales Institute of Mining Engineers. With nearly 500 Plans,
  Diagrams, and other Illustrations. Second Edition, Revised, with
  Additions. Medium 8vo, about 700 pages. Price £1 5_s._ strongly
  bound.

SUMMARY OF CONTENTS.

GEOLOGY.--SEARCH FOR COAL.--MINERAL LEASES AND OTHER
HOLDINGS.--SHAFT SINKING.--FITTING UP THE SHAFT AND SURFACE
ARRANGEMENTS.--STEAM BOILERS AND THEIR FITTINGS.--TIMBERING
AND WALLING.--NARROW WORK AND METHODS OF WORKING.--UNDERGROUND
CONVEYANCE.--DRAINAGE.--THE GASES MET WITH IN MINES;
VENTILATION.--ON THE FRICTION OF AIR IN MINES.--THE PRIESTMAN OIL
ENGINE; PETROLEUM AND NATURAL GAS.--SURVEYING AND PLANNING.--SAFETY
LAMPS AND FIRE-DAMP DETECTORS.--SUNDRY AND INCIDENTAL OPERATIONS
AND APPLIANCES.--COLLIERY EXPLOSIONS.--MISCELLANEOUS QUESTIONS &
ANSWERS.

_Appendix_: SUMMARY OF REPORT OF H.M. COMMISSIONERS ON ACCIDENTS IN
MINES.

*** OPINIONS OF THE PRESS.

  "Mr. Pamely has not only given us a comprehensive reference
  book of a very high order, suitable to the requirements of
  mining-engineers and colliery managers, but at the same time has
  provided mining students with a class-book that is as interesting
  as it is instructive."--_Colliery Manager._

  "Mr. Pamely's work is eminently suited to the purpose for which
  it is intended--being clear, interesting, exhaustive, rich in
  detail, and up to date, giving descriptions of the very latest
  machines in every department.... A mining engineer could scarcely
  go wrong who followed this work."--_Colliery Guardian._

  "This is the most complete 'all round' work on coal-mining
  published in the English language.... No library of coal-mining
  books is complete without it."--_Colliery Engineer_ (Scranton,
  Pa., U.S.A.).

  "Mr. Pamely's work is in all respects worthy of our admiration.
  No person in any responsible position connected with mines should
  be without a copy."--_Westminster Review._


_=Coal and Iron.=_

  _THE COAL AND IRON INDUSTRIES OF THE UNITED KINGDOM._ Comprising
  a Description of the Coal Fields, and of the Principal Seams of
  Coal, with Returns of their Produce and its Distribution, and
  Analyses of Special Varieties. Also an Account of the occurrence
  of Iron Ores in Veins or Seams; Analyses of each Variety; and
  a History of the Rise and Progress of Pig Iron Manufacture. By
  RICHARD MEADE, Assistant Keeper of Mining Records. With Maps.
  8vo, £1 8_s._ cloth.

  "The book is one which must find a place on the shelves of all
  interested in coal and iron production, and in the iron, steel
  and other metallurgical industries."--_Engineer._

  "Of this book we may unreservedly say that it is the best of
  its class which we have ever met.... A book of reference which
  no one engaged in the iron or coal trades should omit from his
  library."--_Iron and Coal Trades Review._


_=Coal Mining.=_

  _COAL AND COAL MINING: A Rudimentary Treatise on._ By the late
  Sir WARINGTON W. SMYTH, M.A., F.R.S., &c., Chief Inspector of the
  Mines of the Crown. Seventh Edition, Revised and Enlarged. With
  numerous Illustrations. 12mo, 4_s._ cloth boards.

  "As an outline is given of every known coal-field in this
  and other countries, as well as of the principal methods of
  working, the book will doubtless interest a very large number of
  readers."--_Mining Journal._


_=Subterraneous Surveying.=_

  _SUBTERRANEOUS SURVEYING, Elementary and Practical Treatise on_,
  with and without the Magnetic Needle. By THOMAS FENWICK, Surveyor
  of Mines, and THOMAS BAKER, C.E. Illust. 12mo, 3_s._ cloth boards.


_=Granite Quarrying.=_

  _GRANITES AND OUR GRANITE INDUSTRIES._ By GEORGE F. HARRIS,
  F.G.S., Membre de la Société Belge de Géologie, Lecturer
  on Economic Geology at the Birkbeck Institution, &c. With
  Illustrations. Crown 8vo, 2_s._ 6_d._ cloth.

  "A clearly and well-written manual on the granite
  industry."--_Scotsman._

  "An interesting work, which will be deservedly
  esteemed."--_Colliery Guardian._

  "An exceedingly interesting and valuable monograph on a subject
  which has hitherto received unaccountably little attention in the
  shape of systematic literary treatment."--_Scottish Leader._


_=Gold, Metallurgy of.=_

  _THE METALLURGY OF GOLD_: A Practical Treatise on the
  Metallurgical Treatment of Gold-bearing Ores. Including the
  Processes of Concentration and Chlorination, and the Assaying,
  Melting, and Refining of Gold. By M. EISSLER, Mining Engineer and
  Metallurgical Chemist, formerly Assistant Assayer of the U. S.
  Mint, San Francisco. Third Edition, Revised and greatly Enlarged.
  With 187 Illustrations. Crown 8vo, 12_s._ 6_d._ cloth.

  "This book thoroughly deserves its title of a 'Practical
  Treatise.' The whole process of gold milling, from the breaking
  of the quartz to the assay of the bullion, is described in clear
  and orderly narrative and with much, but not too much, fulness of
  detail."--_Saturday Review._

  "The work is a storehouse of information and valuable data, and
  we strongly recommend it to all professional men engaged in the
  gold-mining industry."--_Mining Journal._


_=Silver, Metallurgy of.=_

  _THE METALLURGY OF SILVER_: A Practical Treatise on the
  Amalgamation, Roasting, and Lixiviation of Silver Ores. Including
  the Assaying, Melting and Refining, of Silver Bullion. By M.
  EISSLER, Author of "The Metallurgy of Gold," &c. Second Edition,
  Enlarged. With 150 Illustrations. Crown 8vo, 10_s._ 6_d._ cloth.

  "A practical treatise, and a technical work which we are
  convinced will supply a long-felt want amongst practical men, and
  at the same time be of value to students and others indirectly
  connected with the industries."--_Mining Journal._

  "From first to last the book is thoroughly sound and
  reliable."--_Colliery Guardian._

  "For chemists, practical miners, assayers, and investors alike,
  we do not know of any work on the subject so handy and yet so
  comprehensive."--_Glasgow Herald._


_=Lead, Metallurgy of.=_

  _THE METALLURGY OF ARGENTIFEROUS LEAD_: A Practical Treatise
  on the Smelting of Silver-Lead Ores and the Refining of Lead
  Bullion. Including Reports on various Smelting Establishments and
  Descriptions of Modern Smelting Furnaces and Plants in Europe and
  America. By M. EISSLER, M.E., Author of "The Metallurgy of Gold,"
  &c. Crown 8vo, 400 pp., with 183 Illustrations, 12_s._ 6_d._
  cloth.

  "The numerous metallurgical processes, which are fully and
  extensively treated of, embrace all the stages experienced in
  the passage of the lead from the various natural states to its
  issue from the refinery as an article of commerce."--_Practical
  Engineer._

  "The present volume fully maintains the reputation of the author.
  Those who wish to obtain a thorough insight into the present
  state of this industry cannot do better than read this volume,
  and all mining engineers cannot fail to find many useful hints
  and suggestions in it."--_Industries._

  "It is most carefully written and illustrated with capital
  drawings and diagrams. In fact, it is the work of an expert
  for experts, by whom it will be prized as an indispensable
  text-book."--_Bristol Mercury._


_=Iron, Metallurgy of.=_

  _METALLURGY OF IRON._ Containing History of Iron Manufacture,
  Methods of Assay, and Analyses of Iron Ores, Processes of
  Manufacture of Iron and Steel, &c. By H. BAUERMAN, F.G.S.,
  A.R.S.M. With numerous Illustrations. Sixth Edition, Revised and
  Enlarged. 12mo, 5_s._ 6_d._ cloth.

  "Carefully written, it has the merit of brevity and conciseness,
  as to less important points, while all material matters are very
  fully and thoroughly entered into."--_Standard._


_=Iron Mining.=_

  _THE IRON ORES OF GREAT BRITAIN AND IRELAND_: Their Mode of
  Occurrence, Age, and Origin, and the Methods of Searching for
  and Working them, with a Notice of some of the Iron Ores of
  Spain. By J. D. KENDALL, F.G.S., Mining Engineer. With Plates and
  Illustrations. Crown 8vo, 16_s._ cloth.

  "The author has a thorough practical knowledge of his subject,
  and has supplemented a careful study of the available literature
  by unpublished information derived from his own observations.
  The result is a very useful volume which cannot fail to
  be of value to all interested in the iron industry of the
  country."--_Industries._

  "Constitutes a systematic and careful account of our present
  knowledge of the origin and occurrence of the iron ores of Great
  Britain, and embraces a description of the means employed in
  reaching and working these ores."--_Iron._

  "Mr. Kendall is a great authority on this subject and writes from
  personal observation."--_Colliery Guardian._

  "Mr. Kendall's book is thoroughly well done. In it there are the
  outlines of the history of ore mining in every centre and there
  is everything that we want to know as to the character of the
  ores of each district, their commercial value and the cost of
  working them."--_Iron and Steel Trades Journal._


ELECTRICITY, ELECTRICAL ENGINEERING, etc.


_=Electrical Engineering.=_

  _THE ELECTRICAL ENGINEER'S POCKET-BOOK OF MODERN RULES, FORMULÆ,
  TABLES, AND DATA._ By H. R. KEMPE, M.Inst.E.E., A.M.Inst.C.E.,
  Technical Officer, Postal Telegraphs, Author of "A Handbook of
  Electrical Testing," &c. Second Edition, thoroughly Revised, with
  Additions. With numerous Illustrations. Royal 32mo, oblong, 5_s._
  leather.

  "There is very little in the shape of formulæ or data which the
  electrician is likely to want in a hurry which cannot be found in
  its pages."--_Practical Engineer._

  "A very useful book of reference for daily use in practical
  electrical engineering and its various applications to the
  industries of the present day."--_Iron._

  "It is the best book of its kind."--_Electrical Engineer._

  "Well arranged and compact. The 'Electrical Engineer's
  Pocket-Book' is a good one."--_Electrician._

  "Strongly recommended to those engaged in the various electrical
  industries."--_Electrical Review._


_=Electric Lighting.=_

  _ELECTRIC LIGHT FITTING_: A Handbook for Working Electrical
  Engineers, embodying Practical Notes on Installation Management.
  By JOHN W. URQUHART, Electrician, Author of "Electric Light,"
  &c. With numerous Illustrations. Second Edition, Revised, with
  Additional Chapters. Crown 8vo, 5_s._ cloth.

  "This volume deals with what may be termed the mechanics of
  electric lighting, and is addressed to men who are already
  engaged in the work or are training for it. The work traverses
  a great deal of ground, and may be read as a sequel to the same
  author's useful work on 'Electric Light.'"--_Electrician._

  "This is an attempt to state in the simplest language the
  precautions which should be adopted in installing the electric
  light, and to give information, for the guidance of those who
  have to run the plant when installed. The book is well worth the
  perusal of the workmen for whom it is written."--_Electrical
  Review._

  "We have read this book with a good deal of pleasure. We believe
  that the book will be of use to practical workmen, who will not
  be alarmed by finding mathematical formulæ which they are unable
  to understand."--_Electrical Plant._

  "Eminently practical and useful.... Ought to be in the hands of
  everyone in charge of an electric light plant."--_Electrical
  Engineer._

  "Mr. Urquhart has succeeded in producing a really capital book,
  which we have no hesitation in recommending to the notice of
  working electricians and electrical engineers."--_Mechanical
  World._


_=Electric Light.=_

  _ELECTRIC LIGHT: Its Production and Use._ Embodying Plain
  Directions for the Treatment of Dynamo-Electric Machines,
  Batteries, Accumulators, and Electric Lamps. By J. W. URQUHART,
  C.E., Author of "Electric Light Fitting," "Electroplating," &c.
  Fifth Edition, carefully Revised, with Large Additions and 145
  Illustrations. Crown 8vo, 7_s._ 6_d._ cloth.

  "The whole ground of electric lighting is more or less covered
  and explained in a very clear and concise manner."--_Electrical
  Review._

  "Contains a good deal of very interesting information, especially
  in the parts where the author gives dimensions and working
  costs."--_Electrical Engineer._

  "A miniature _vade-mecum_ of the salient facts connected with the
  science of electric lighting."--_Electrician._

  "You cannot for your purpose have a better book than 'Electric
  Light,' by Urquhart."--_Engineer._

  "The book is by far the best that we have yet met with on the
  subject."--_Athenæum._


_=Construction of Dynamos.=_

  _DYNAMO CONSTRUCTION: A Practical Handbook for the Use of
  Engineer Constructors and Electricians-in-Charge._ Embracing
  Framework Building, Field Magnet and Armature Winding and
  Grouping, Compounding, &c. With Examples of leading English,
  American, and Continental Dynamos and Motors. By J. W. URQUHART,
  Author of "Electric Light," "Electric Light Fitting," &c. With
  upwards of 100 Illustrations. Crown 8vo, 7_s._ 6_d._ cloth.

  "Mr. Urquhart's book is the first one which deals with these
  matters in such a way that the engineering student can
  understand them. The book is very readable, and the author
  leads his readers up to difficult subjects by reasonably simple
  tests."--_Engineering Review._

  "The author deals with his subject in a style so popular as
  to make his volume a handbook of great practical value to
  engineer contractors and electricians in charge of lighting
  installations."--_Scotsman._

  "'Dynamo Construction' more than sustains the high character
  of the author's previous publications. It is sure to be widely
  read by the large and rapidly-increasing number of practical
  electricians."--_Glasgow Herald._

  "A book for which a demand has long existed."--_Mechanical World._


_=A New Dictionary of Electricity.=_

  _THE STANDARD ELECTRICAL DICTIONARY._ A Popular Dictionary of
  Words and Terms Used in the Practice of Electrical Engineering.
  Containing upwards of 3,000 Definitions. By T. O'CONNOR SLOANE,
  A.M., Ph.D., Author of "The Arithmetic of Electricity," &c. Crown
  8vo, 630 pp., 350 Illustrations, 7_s._ 6_d._ cloth.

  [_Just published._

  "The work has many attractive features in it, and is beyond
  doubt, a well put together and useful publication. The amount of
  ground covered may be gathered from the fact that in the index
  about 5,000 references will be found. The inclusion of such
  comparatively modern words as 'impedence,' 'reluctance,' &c.,
  shows that the author has desired to be up to date, and indeed
  there are other indications of carefulness of compilation. The
  work is one which does the author great credit and it should
  prove of great value, especially to students."--_Electrical
  Review._

  "We have found the book very complete and reliable, and can,
  therefore, commend it heartily."--_Mechanical World._

  "Very complete and contains a large amount of useful
  information."--_Industries._

  "An encyclopædia of electrical science in the compass of a
  dictionary. The information given is sound and clear. The book is
  well printed, well illustrated, and well up to date, and may be
  confidently recommended."--_Builder._

  "We hail the appearance of this little work as one which will
  meet a want that has been keenly felt for some time.... The
  author is to be congratulated on the excellent manner in which he
  has accomplished his task."--_Practical Engineer._

  "The volume is excellently printed and illustrated, and should
  form part of the library of every one who is directly or
  indirectly connected with electrical matters."--_Hardware Trade
  Journal._


_=Electric Lighting of Ships.=_

  _ELECTRIC SHIP-LIGHTING_: A Handbook on the Practical Fitting and
  Running of Ship's Electrical Plant. For the Use of Shipowners and
  Builders, Marine Electricians, and Sea-going Engineers-in-Charge.
  By J. W. URQUHART, C.E., Author of "Electric Light," &c. With 88
  Illustrations. Crown 8vo, 7_s._ 6_d._ cloth.

  "The subject of ship electric lighting is one of vast importance
  in these days, and Mr. Urquhart is to be highly complimented for
  placing such a valuable work at the service of the practical
  marine electrician."--_The Steamship._

  "Distinctly a book which of its kind stands almost alone, and for
  which there should be a demand."--_Electrical Review._


_=Electric Lighting.=_

  _THE ELEMENTARY PRINCIPLES OF ELECTRIC LIGHTING._ By ALAN A.
  CAMPBELL SWINTON, Associate I.E.E. Third Edition, Enlarged and
  Revised. With 16 Illustrations. Crown 8vo, 1_s._ 6_d._ cloth.

  "Anyone who desires a short and thoroughly clear exposition of
  the elementary principles of electric lighting cannot do better
  than read this little work."--_Bradford Observer._


_=Dynamic Electricity.=_

  _THE ELEMENTS OF DYNAMIC ELECTRICITY AND MAGNETISM._ By
  PHILIP ATKINSON, A.M., Ph.D., Author of "Elements of Static
  Electricity," "The Elements of Electric Lighting," &c. &c. Crown
  8vo, 417 pp., with 120 Illustrations, 10_s._ 6_d._ cloth.


_=Electric Motors, &c.=_

  _THE ELECTRIC TRANSFORMATION OF POWER_ and its Application by
  the Electric Motor, including Electric Railway Construction. By
  P. ATKINSON, A.M., Ph.D., Author of "The Elements of Electric
  Lighting," &c. With 96 Illustrations. Crown 8vo, 7_s._ 6_d._
  cloth.


_=Dynamo Construction.=_

  _HOW TO MAKE A DYNAMO: A Practical Treatise for Amateurs._
  Containing numerous Illustrations and Detailed Instructions for
  Constructing a Small Dynamo, to Produce the Electric Light. By
  ALFRED CROFTS. Fourth Edition, Revised and Enlarged. Crown 8vo,
  2_s._ cloth.

  "The instructions given in this unpretentious little book
  are sufficiently clear and explicit to enable any amateur
  mechanic possessed of average skill and the usual tools to be
  found in an amateur's workshop, to build a practical dynamo
  machine."--_Electrician._


_=Text Book of Electricity.=_

  _THE STUDENT'S TEXT-BOOK OF ELECTRICITY._ By HENRY M. NOAD,
  Ph.D., F.R.S. New Edition, carefully Revised. With Introduction
  and Additional Chapters, by W. H. PREECE, M.I.C.E. Crown 8vo,
  12_s._ 6_d._ cloth.


_=Electricity.=_

  _A MANUAL OF ELECTRICITY: Including Galvanism, Magnetism,
  Dia-Magnetism, Electro-Dynamics._ By HENRY M. NOAD, Ph.D., F.R.S.
  Fourth Edition (1859). 8vo, £1 4_s._ cloth.


ARCHITECTURE, BUILDING, etc.


_=Building Construction.=_

  _PRACTICAL BUILDING CONSTRUCTION_: A Handbook for Students
  Preparing for Examinations, and a Book of Reference for
  Persons Engaged in Building. By JOHN PARNELL ALLEN, Surveyor,
  Lecturer on Building Construction at the Durham College of
  Science, Newcastle-on-Tyne. Medium 8vo, 450 pages, with 1,000
  Illustrations. 12_s._ 6_d._ cloth.

  [_Just published._

  "This volume is one of the most complete expositions of building
  construction we have seen. It contains all that is necessary
  to prepare students for the various examinations in building
  construction."--_Building News._

  "The author depends nearly as much on his diagrams as on his
  type. The pages suggest the hand of a man of experience in
  building operations--and the volume must be a blessing to many
  teachers as well as to students."--_The Architect._

  "This volume promises to be the recognised handbook in all
  advanced classes where building construction is taught from a
  practical point of view. We strongly commend the book to the
  notice of all teachers of building construction."--_Technical
  World._

  "The work is sure to prove a formidable rival to great and small
  competitors alike, and bids fair to take a permanent place as a
  favourite students' text-book. The large number of illustrations
  deserve particular mention for the great merit they possess for
  purposes of reference, in exactly corresponding to convenient
  scales."--_Jour. Inst. Brit. Archts._


_=Concrete.=_

  _CONCRETE: ITS NATURE AND USES._ A Book for Architects, Builders,
  Contractors, and Clerks of Works. By GEORGE L. SUTCLIFFE,
  A.R.I.B.A. 350 pages, with numerous Illustrations. Crown 8vo,
  7_s._ 6_d._ cloth.

  [_Just published._

  "The author treats a difficult subject in a lucid manner. The
  manual fills a long-felt gap. It is careful and exhaustive;
  equally useful as a student's guide and a architect's book of
  reference."--_Journal of Royal Institution of British Architects._

  "There is room for this new book, which will probably be for
  some time the standard work on the subject for a builder's
  purpose."--_Glasgow Herald._

  "A thoroughly useful and comprehensive work."--_British
  Architect._


_=Mechanics for Architects.=_

  _THE MECHANICS OF ARCHITECTURE_: A Treatise on Applied Mechanics,
  especially Adapted to the Use of Architects. By E. W. TARN,
  M.A., Author of "The Science of Building," &c. Second Edition,
  Enlarged. Illust. with 125 Diagrams. Cr. 8vo, 7_s._ 6_d._ cloth.

  [_Just published._

  "The book is a very useful and helpful manual of architectural
  mechanics, and really contains sufficient to enable a careful
  and painstaking student to grasp the principles bearing upon
  the majority of building problems.... Mr. Tarn has added, by
  this volume, to the debt of gratitude which is owing to him by
  architectural students for the many valuable works which he has
  produced for their use."--_The Builder._

  "The mechanics in the volume are really mechanics, and are
  harmoniously wrought in with the distinctive professional manner
  proper to the subject. The diagrams and type are commendably
  clear."--_The Schoolmaster._


_=The New Builder's Price Book, 1894.=_

  _LOCKWOOD'S BUILDER'S PRICE BOOK FOR 1894._ A Comprehensive
  Handbook of the Latest Prices and Data for Builders, Architects,
  Engineers, and Contractors. _Re-constructed, Re-written, and
  Greatly Enlarged._ By FRANCIS T. W. MILLER. 700 closely-printed
  pages, crown 8vo, 4_s._ cloth.

  "This book is a very useful one, and should find a place in
  every English office connected with the building and engineering
  professions."--_Industries._

  "An excellent book of reference."--_Architect._

  "In its new and revised form this Price Book is what a work of
  this kind should be--comprehensive, reliable, well arranged,
  legible, and well bound."--_British Architect._


_=Designing Buildings.=_

  _THE DESIGN OF BUILDINGS_: Being Elementary Notes on the
  Planning, Sanitation and Ornamentive Formation of Structures,
  based on Modern Practice. Illustrated with Nine Folding Plates.
  By W. WOODLEY, Assistant Master, Metropolitan Drawing Classes,
  &c. Demy 8vo, 6_s._ cloth.

  [_Just published._


_=Sir Wm. Chambers's Treatise on Civil Architecture.=_

  _THE DECORATIVE PART OF CIVIL ARCHITECTURE._ By Sir WILLIAM
  CHAMBERS, F.R.S. With Portrait, Illustrations, Notes, and an
  Examination of Grecian Architecture, by JOSEPH GWILT, F.S.A.
  Revised and Edited by W. H. LEEDS. 66 Plates, 4to, 21_s._ cloth.


_=Villa Architecture.=_

  _A HANDY BOOK OF VILLA ARCHITECTURE: Being a Series of
  Designs for Villa Residences in various Styles._ With Outline
  Specifications and Estimates. By C. WICKES, Architect, Author of
  "The Spires and Towers of England," &c. 61 Plates, 4to, £1 11_s._
  6_d._ half-morocco.

  "The whole of the designs bear evidence of their being the work
  of an artistic architect, and they will prove very valuable and
  suggestive."--_Building News._


_=Text-Book for Architects.=_

  _THE ARCHITECT'S GUIDE: Being a Text-Book of Useful Information
  for Architects, Engineers, Surveyors, Contractors, Clerks of
  Works, &c. &c._ By FREDERICK ROGERS, Architect. Third Edition.
  Crown 8vo, 3_s._ 6_d._ cloth.

  "As a text-book of useful information for architects, engineers,
  surveyors, &c., it would be hard to find a handier or more
  complete little volume."--_Standard._


_=Taylor and Cresy's Rome.=_

  _THE ARCHITECTURAL ANTIQUITIES OF ROME._ By the late G. L.
  TAYLOR, Esq., F.R.I.B.A., and EDWARD CRESY, Esq. New Edition,
  thoroughly Revised by the Rev. ALEXANDER TAYLOR, M.A. (son of the
  late G. L. Taylor, Esq.), Fellow of Queen's College, Oxford, and
  Chaplain of Gray's Inn. Large folio, with 130 Plates, £3 3_s._
  half-bound.

  "Taylor and Cresy's work has from its first publication
  been ranked among those professional books which cannot be
  bettered."--_Architect._


_=Linear Perspective.=_

  _ARCHITECTURAL PERSPECTIVE_: The whole Course and Operations of
  the Draughtsman in Drawing a Large House in Linear Perspective.
  Illustrated by 39 Folding Plates. By F. O. FERGUSON. 8vo, 3_s._
  6_d._ boards.

  "It is the most intelligible of the treatises on this ill-treated
  subject that I have met with."--E. INGRESS BELL, Esq., in the
  _R.I.B.A. Journal_.


_=Architectural Drawing.=_

  _PRACTICAL RULES ON DRAWING, for the Operative Builder and Young
  Student in Architecture._ By GEORGE PYNE. With 14 Plates, 4to,
  7_s._ 6_d._ boards.


_=Vitruvius' Architecture.=_

  _THE ARCHITECTURE of MARCUS VITRUVIUS POLLIO._ Translated by
  JOSEPH GWILT, F.S.A., F.R.A.S. New Edition, Revised by the
  Translator. With 23 Plates. Fcap. 8vo, 5_s._ cloth.


_=Designing, Measuring, and Valuing.=_

  _THE STUDENT'S GUIDE to the PRACTICE of MEASURING AND VALUING
  ARTIFICERS' WORK._ Containing Directions for taking Dimensions,
  Abstracting the same, and bringing the Quantities into Bill,
  with Tables of Constants for Valuation of Labour, and for the
  Calculation of Areas and Solidities. Originally edited by EDWARD
  DOBSON, Architect. With Additions by E. WYNDHAM TARN, M.A. Sixth
  Edition. With 8 Plates and 63 Woodcuts. Crown 8vo, 7_s._ 6_d._
  cloth.

  "This edition will be found the most complete treatise on the
  principles of measuring and valuing artificers' work that has yet
  been published."--_Building News._


_=Pocket Estimator and Technical Guide.=_

  _THE POCKET TECHNICAL GUIDE, MEASURER, AND ESTIMATOR FOR BUILDERS
  AND SURVEYORS._ Containing Technical Directions for Measuring
  Work in all the Building Trades, Complete Specifications for
  Houses, Roads, and Drains, and an easy Method of Estimating the
  parts of a Building collectively. By A. C. BEATON. Sixth Edit.
  Waistcoat-pocket size, 1_s._ 6_d._ leather, gilt edges.

  "No builder, architect, surveyor, or valuer should be without his
  'Beaton.'"--_Building News._


_=Donaldson on Specifications.=_

  _THE HANDBOOK OF SPECIFICATIONS_; or, Practical Guide to the
  Architect, Engineer, Surveyor, and Builder, in drawing up
  Specifications and Contracts for Works and Constructions.
  Illustrated by Precedents of Buildings actually executed by
  eminent Architects and Engineers. By Professor T. L. DONALDSON,
  P.R.I.B.A., &c. New Edition. 8vo, with upwards of 1,000 pages of
  Text, and 33 Plates. £1 11_s._ 6_d._ cloth.

  "Valuable as a record, and more valuable still as a book of
  precedents.... Suffice it to say that Donaldson's 'Handbook of
  Specifications' must be bought by all architects."--_Builder._


_=Bartholomew and Rogers' Specifications.=_

  _SPECIFICATIONS FOR PRACTICAL ARCHITECTURE._ A Guide to the
  Architect, Engineer, Surveyor, and Builder. With an Essay on the
  Structure and Science of Modern Buildings. Upon the Basis of the
  Work by ALFRED BARTHOLOMEW, thoroughly Revised, Corrected, and
  greatly added to by FREDERICK ROGERS, Architect. Third Edition,
  Revised, with Additions. With numerous Illustrations. Medium 8vo,
  15_s._ cloth.

  "The collection of specifications prepared by Mr. Rogers on
  the basis of Bartholomew's work is too well known to need any
  recommendation from us. It is one of the books with which every
  young architect must be equipped."--_Architect._


_=Construction.=_

  _THE SCIENCE OF BUILDING: An Elementary Treatise on the
  Principles of Construction._ By E. WYNDHAM TARN, M.A., Architect.
  Third Edition, Revised and Enlarged. With 59 Engravings. Fcap.
  8vo, 4_s._ cl.

  "A very valuable book, which we strongly recommend to all
  students."--_Builder._


_=House Building and Repairing.=_

  _THE HOUSE-OWNER'S ESTIMATOR_; or, What will it Cost to Build,
  Alter, or Repair? A Price Book for Unprofessional People, as well
  as the Architectural Surveyor and Builder. By JAMES D. SIMON.
  Edited by FRANCIS T. W. MILLER, A.R.I.B.A. Fourth Edition. Crown
  8vo, 3_s._ 6_d._ cloth.

  "In two years it will repay its cost a hundred times
  over."--_Field._


_=Cottages and Villas.=_

  _COUNTRY AND SUBURBAN COTTAGES AND VILLAS_: How to Plan and
  Build Them. Containing 33 Plates, with Introduction, General
  Explanations, and Description of each Plate. By JAMES W. BOGUE,
  Architect, Author of "Domestic Architecture," &c. 4to, 10_s._
  6_d._ cloth.


_=Building; Civil and Ecclesiastical.=_

  _A BOOK ON BUILDING, Civil and Ecclesiastical_, including Church
  Restoration; with the Theory of Domes and the Great Pyramid, &c.
  By Sir EDMUND BECKETT, Bart., LL.D., F.R.A.S. Second Edition.
  Fcap. 8vo, 5_s._ cloth.

  "A book which is always amusing and nearly always
  instructive."--_Times._


_=Sanitary Houses, etc.=_

  _THE SANITARY ARRANGEMENTS OF DWELLING-HOUSES._ By A. J. WALLIS
  TAYLER, A.M. Inst. C.E. Crown 8vo, with numerous Illustrations.
  Price about 3_s._ cloth.

  [_Nearly ready._


_=Ventilation of Buildings.=_

  _VENTILATION. A Text Book to the Practice of the Art of
  Ventilating Buildings._ By W. P. BUCHAN, R.P. 12mo, 4_s._ cloth.

  "Contains a great amount of useful practical information, as
  thoroughly interesting as it is technically reliable."--_British
  Architect._


_=The Art of Plumbing.=_

  _PLUMBING. A Text Book to the Practice of the Art or Craft of the
  Plumber._ By WILLIAM PATON BUCHAN, R.P. Sixth Edition, Enlarged.
  12mo, 4_s._ cloth.

  "A text-book which may be safely put in the hands of every young
  plumber."--_Builder._


_=Geometry for the Architect, Engineer, etc.=_

  _PRACTICAL GEOMETRY, for the Architect, Engineer, and Mechanic._
  Giving Rules for the Delineation and Application of various
  Geometrical Lines, Figures and Curves. By E. W. TARN, M.A.,
  Architect. 8vo, 9_s._ cloth.

  "No book with the same objects in view has ever been published in
  which the clearness of the rules laid down and the illustrative
  diagrams have been so satisfactory."--_Scotsman._


_=The Science of Geometry.=_

  _THE GEOMETRY OF COMPASSES; or, Problems Resolved by the mere
  Description of Circles, and the use of Coloured Diagrams and
  Symbols._ By OLIVER BYRNE. Coloured Plates. Crown 8vo, 3_s._
  6_d._ cloth.


CARPENTRY, TIMBER, etc.


_=Tredgold's Carpentry, Revised & Enlarged by Tarn.=_

  _THE ELEMENTARY PRINCIPLES OF CARPENTRY._ A Treatise on the
  Pressure and Equilibrium of Timber Framing, the Resistance of
  Timber, and the Construction of Floors, Arches, Bridges, Roofs,
  Uniting Iron and Stone with Timber, &c. To which is added
  an Essay on the Nature and Properties of Timber, &c., with
  Descriptions of the kinds of Wood used in Building; also numerous
  Tables of the Scantlings of Timber for different purposes, the
  Specific Gravities of Materials, &c. By THOMAS TREDGOLD, C.E.
  With an Appendix of Specimens of Various Roofs of Iron and Stone,
  Illustrated. Seventh Edition, thoroughly revised and considerably
  enlarged by E. WYNDHAM TARN, M.A., Author of "The Science of
  Building," &c. With 61 Plates, Portrait of the Author, and
  several Woodcuts. In One large Vol., 4to, price £1 5_s._ cloth.

  "Ought to be in every architect's and every builder's
  library."--_Builder._

  "A work whose monumental excellence must commend it wherever
  skilful carpentry is concerned. The author's principles are
  rather confirmed than impaired by time. The additional plates are
  of great intrinsic value."--_Building News._


_=Woodworking Machinery.=_

  _WOODWORKING MACHINERY_: Its Rise, Progress, and Construction.
  With Hints on the Management of Saw Mills and the Economical
  Conversion of Timber. Illustrated with Examples of Recent Designs
  by leading English, French, and American Engineers. By M. POWIS
  BALE, A.M.Inst.C.E., M.I.M.E. Second Edition, Revised, with large
  Additions. Large crown 8vo, 440 pp., 9_s._ cloth.

  [_Just published._

  "Mr. Bale is evidently an expert on the subject and he has
  collected so much information that his book is all-sufficient
  for builders and others engaged in the conversion of
  timber."--_Architect._

  "The most comprehensive compendium of wood-working machinery
  we have seen. The author is a thorough master of his
  subject."--_Building News._


_=Saw Mills.=_

  _SAW MILLS_: Their Arrangement and Management, and the Economical
  Conversion of Timber. (A Companion Volume to "Woodworking
  Machinery.") By M. POWIS BALE. Crown 8vo, 10_s._ 6_d._ cloth.

  "The _administration_ of a large sawing establishment is
  discussed, and the subject examined from a financial standpoint.
  Hence the size, shape, order, and disposition of saw-mills and
  the like are gone into in detail, and the course of the timber
  is traced from its reception to its delivery in its converted
  state. We could not desire a more complete or practical
  treatise."--_Builder._


_=Nicholson's Carpentry.=_

  _THE CARPENTER'S NEW GUIDE_; or, Book of Lines for Carpenters;
  comprising all the Elementary Principles essential for acquiring
  a knowledge of Carpentry. Founded on the late PETER NICHOLSON'S
  Standard Work. New Edition, Revised by A. ASHPITEL, F.S.A. With
  Practical Rules on Drawing, by G. PYNE. With 74 Plates, 4to, £1
  1_s._ cloth.


_=Handrailing and Stairbuilding.=_

  _A PRACTICAL TREATISE ON HANDRAILING_: Showing New and Simple
  Methods for Finding the Pitch of the Plank, Drawing the Moulds,
  Bevelling, Jointing-up, and Squaring the Wreath. By GEORGE
  COLLINGS. Second Edition, Revised and Enlarged, to which is added
  A TREATISE ON STAIRBUILDING. 12mo, 2_s._ 6_d._ cloth limp.

  "Will be found of practical utility in the execution of this
  difficult branch of joinery."--_Builder._

  "Almost every difficult phase of this somewhat intricate branch
  of joinery is elucidated by the aid of plates and explanatory
  letterpress."--_Furniture Gazette._


_=Circular Work.=_

  _CIRCULAR WORK IN CARPENTRY AND JOINERY_: A Practical Treatise on
  Circular Work of Single and Double Curvature. By GEORGE COLLINGS.
  With Diagrams. Second Edit, 12mo, 2_s._ 6_d._ cloth limp.

  "An excellent example of what a book of this kind should be.
  Cheap in price, clear in definition and practical in the examples
  selected."--_Builder._


_=Handrailing.=_

  _HANDRAILING COMPLETE IN EIGHT LESSONS._ On the Square-Cut
  System. By J. S. GOLDTHORP, Teacher of Geometry and Building
  Construction at the Halifax Mechanic's Institute. With Eight
  Plates and over 150 Practical Exercises. 4to, 3_s._ 6_d._ cloth.

  "Likely to be of considerable value to joiners and others who
  take a pride in good work. We heartily commend it to teachers and
  students."--_Timber Trades Journal._


_=Timber Merchant's Companion.=_

  _THE TIMBER MERCHANT'S AND BUILDER'S COMPANION._ Containing New
  and Copious Tables of the Reduced Weight and Measurement of Deals
  and Battens, of all sizes, from One to a Thousand Pieces, and
  the relative Price that each size bears per Lineal Foot to any
  given Price per Petersburg Standard Hundred; the Price per Cube
  Foot of Square Timber to any given Price per Load of 50 Feet;
  the proportionate Value of Deals and Battens by the Standard,
  to Square Timber by the Load of 50 Feet; the readiest mode of
  ascertaining the Price of Scantling per Lineal Foot of any size,
  to any given Figure per Cube Foot, &c. &c. By WILLIAM DOWSING.
  Fourth Edition, Revised and Corrected. Cr. 8vo, 3_s._ cl.

  "Everything is as concise and clear as it can possibly be made.
  There can be no doubt that every timber merchant and builder
  ought to possess it."--_Hull Advertiser._

  "We are glad to see a fourth edition of these admirable tables,
  which for correctness and simplicity of arrangement leave nothing
  to be desired."--_Timber Trades Journal._


_=Practical Timber Merchant.=_

  _THE PRACTICAL TIMBER MERCHANT._ Being a Guide for the use of
  Building Contractors, Surveyors, Builders, &c., comprising useful
  Tables for all purposes connected with the Timber Trade, Marks of
  Wood, Essay on the Strength of Timber, Remarks on the Growth of
  Timber, &c. By W. RICHARDSON. Fcap. 8vo, 3_s._ 6_d._ cloth.

  "This handy manual contains much valuable information for
  the use of timber merchants, builders, foresters, and all
  others connected with the growth, sale, and manufacture of
  timber."--_Journal of Forestry._


_=Timber Freight Book.=_

  _THE TIMBER MERCHANT'S, SAW MILLER'S, AND IMPORTER'S FREIGHT BOOK
  AND ASSISTANT._ Comprising Rules, Tables, and Memoranda relating
  to the Timber Trade. By WILLIAM RICHARDSON, Timber Broker;
  together with a Chapter on "SPEEDS OF SAW MILL MACHINERY," by M.
  POWIS BALE, M.I.M.E., &c. 12mo, 3_s._ 6_d._ cl. boards.

  "A very useful manual of rules, tables, and memoranda relating to
  the timber trade. We recommend it as a compendium of calculation
  to all timber measurers and merchants, and as supplying a real
  want in the trade."--_Building News._


_=Packing-Case Makers, Tables for.=_

  _PACKING-CASE TABLES_; showing the number of Superficial Feet in
  Boxes or Packing-Cases, from six inches square and upwards. By W.
  RICHARDSON, Timber Broker. Third Edition. Oblong 4to, 3_s._ 6_d._
  cl.

  "Invaluable labour-saving tables."--_Ironmonger._

  "Will save much labour and calculation."--_Grocer._


_=Superficial Measurement.=_

  _THE TRADESMAN'S GUIDE TO SUPERFICIAL MEASUREMENT._ Tables
  calculated from 1 to 200 inches in length, by 1 to 108 inches in
  breadth. For the use of Architects, Surveyors, Engineers, Timber
  Merchants, Builders, &c. By JAMES HAWKINGS. Fourth Edition.
  Fcap., 3_s._ 6_d._ cloth.

  "A useful collection of tables to facilitate rapid calculation
  of surfaces. The exact area of any surface of which the limits
  have been ascertained can be instantly determined. The book will
  be found of the greatest utility to all engaged in building
  operations."--_Scotsman._

  "These tables will be found of great assistance to
  all who require to make calculations in superficial
  measurement."--_English Mechanic._


_=Forestry.=_

  _THE ELEMENTS OF FORESTRY._ Designed to afford Information
  concerning the Planting and Care of Forest Trees for Ornament or
  Profit, with Suggestions upon the Creation and Care of Woodlands.
  By F. B. HOUGH. Large crown 8vo, 10_s._ cloth.


_=Timber Importer's Guide.=_

  _THE TIMBER IMPORTER'S, TIMBER MERCHANT'S, AND BUILDER'S STANDARD
  GUIDE._ By RICHARD E. GRANDY. Comprising an Analysis of Deal
  Standards, Home and Foreign, with Comparative Values and Tabular
  Arrangements for fixing Net Landed Cost on Baltic and North
  American Deals, including all intermediate Expenses, Freight,
  Insurance, &c. &c. Together with copious Information for the
  Retailer and Builder. Third Edition, Revised. 12mo, 2_s._ cloth
  limp.

  "Everything it pretends to be: built up gradually, it leads one
  from a forest to a treenail, and throws in, as a makeweight,
  a host of material concerning bricks, columns, cisterns,
  &c."--_English Mechanic._


DECORATIVE ARTS, etc.


_=Woods and Marbles (Imitation of).=_

  _SCHOOL OF PAINTING FOR THE IMITATION OF WOODS AND MARBLES_, as
  Taught and Practised by A. R. VAN DER BURG and P. VAN DER BURG,
  Directors of the Rotterdam Painting Institution. Royal folio,
  18½ by 12½ in., Illustrated with 24 full-size Coloured Plates;
  also 12 plain Plates, comprising 154 Figures. Second and Cheaper
  Edition. Price £1 11_s._ 6_d._

_List of Plates._

  1. Various Tools required for Wood Painting--2, 3. Walnut:
  Preliminary Stages of Graining and Finished Specimen--4. Tools
  used for Marble Painting and Method of Manipulation--5, 6. St.
  Remi Marble: Earlier Operations and Finished Specimen--7. Methods
  of Sketching different Grains, Knots, &c.--8, 9. Ash: Preliminary
  Stages and Finished Specimen--10. Methods of Sketching Marble
  Grains--11, 12. Breche Marble: Preliminary Stages of Working and
  Finished Specimen--13. Maple: Methods of Producing the different
  Grains--14, 15. Bird's-eye Maple: Preliminary Stages and Finished
  Specimen--16. Methods of Sketching the different Species of White
  Marble--17, 18. White Marble: Preliminary Stages of Process and
  Finished Specimen--19. Mahogany: Specimens of various Grains
  and Methods of Manipulation--20, 21. Mahogany: Earlier Stages
  and Finished Specimen--22, 23, 24. Sienna Marble: Varieties
  of Grain, Preliminary Stages and Finished Specimen--25, 26,
  27. Juniper Wood: Methods of producing Grain, &c.: Preliminary
  Stages and Finished Specimen--28, 29, 30. Vert de Mer Marble:
  Varieties of Grain and Methods of Working Unfinished and Finished
  Specimens--31, 32, 33. Oak: Varieties of Grain, Tools Employed,
  and Methods of Manipulation, Preliminary Stages and Finished
  Specimen--34, 35, 36. Waulsort Marble: Varieties of Grain,
  Unfinished and Finished Specimens.

  "Those who desire to attain skill in the art of painting woods
  and marbles will find advantage in consulting this book....
  Some of the Working Men's Clubs should give their young men the
  opportunity to study it."--_Builder._

  "A comprehensive guide to the art. The explanations of the
  processes, the manipulation and management of the colours, and
  the beautifully executed plates will not be the least valuable to
  the student who aims at making his work a faithful transcript of
  nature."--_Building News._


_=Wall Paper.=_

  _WALL PAPER DECORATION._ By ARTHUR SEYMOUR JENNINGS, Author of
  "Practical Paper Hanging." With numerous Illustrations. Demy 8vo.

  [_In preparation._


_=House Decoration.=_

  _ELEMENTARY DECORATION._ A Guide to the Simpler Forms of Everyday
  Art. Together with _PRACTICAL HOUSE DECORATION_. By JAMES W.
  FACEY. With numerous Illustrations. In One Vol., 5_s._ strongly
  half-bound.


_=House Painting, Graining, etc.=_

  _HOUSE PAINTING, GRAINING, MARBLING, AND SIGN WRITING_, A
  Practical Manual of. By ELLIS A. DAVIDSON. Sixth Edition. With
  Coloured Plates and Wood Engravings. 12mo, 6_s._ cloth boards.

  "A mass of information, of use to the amateur and of value to the
  practical man."--_English Mechanic._


_=Decorators, Receipts for.=_

  _THE DECORATOR'S ASSISTANT_: A Modern Guide to Decorative
  Artists and Amateurs, Painters, Writers, Gilders, &c. Containing
  upwards of 600 Receipts, Rules and Instructions; with a variety
  of Information for General Work connected with every Class of
  Interior and Exterior Decorations, &c. Fifth Edition, Revised.
  152 pp., crown 8vo, 1_s._ in wrapper.

  "Full of receipts of value to decorators, painters, gilders. &c.
  The book contains the gist of larger treatises on colour and
  technical processes. It would be difficult to meet with a work
  so full of varied information on the painter's art."--_Building
  News._


_=Moyr Smith on Interior Decoration.=_

  _ORNAMENTAL INTERIORS, ANCIENT AND MODERN._ By J. MOYR SMITH.
  Super-royal 8vo, with 32 full-page Plates and numerous smaller
  Illustrations, handsomely bound in cloth, gilt top, price 18_s._

  "The book is well illustrated and handsomely got up, and contains
  some true criticism and a good many good examples of decorative
  treatment."--_The Builder._


_=British and Foreign Marbles.=_

  _MARBLE DECORATION and the Terminology of British and Foreign
  Marbles._ A Handbook for Students. By GEORGE H. BLAGROVE, Author
  of "Shoring and its Application," &c. With 28 Illustrations.
  Crown 8vo, 3_s._ 6_d._ cloth.

  "This most useful and much wanted handbook should be in the hands
  of every architect and builder."--_Building World._

  "A carefully and usefully written treatise; the work is
  essentially practical."--_Scotsman._


_=Marble Working, etc.=_

  _MARBLE AND MARBLE WORKERS_: A Handbook for Architects, Artists,
  Masons, and Students. By ARTHUR LEE, Author of "A Visit to
  Carrara," "The Working of Marble," &c. Small crown 8vo, 2_s._
  cloth.

  "A really valuable addition to the technical literature of
  architects and masons."--_Building News._


_DELAMOTTE'S WORKS ON ILLUMINATION AND ALPHABETS._

  _A PRIMER OF THE ART OF ILLUMINATION, for the Use of Beginners_:
  with a Rudimentary Treatise on the Art, Practical Directions for
  its Exercise, and Examples taken from Illuminated MSS., printed
  in Gold and Colours. By F. DELAMOTTE. New and Cheaper Edition.
  Small 4to, 6_s._ ornamental boards.

  "The examples of ancient MSS. recommended to the student, which,
  with much good sense, the author chooses from collections
  accessible to all, are selected with judgment and knowledge, as
  well as taste."--_Athenæum._

  _ORNAMENTAL ALPHABETS, Ancient and Mediæval, from the Eighth
  Century, with Numerals_; including Gothic, Church-Text, large and
  small, German, Italian, Arabesque, Initials for Illumination,
  Monograms, Crosses, &c. &c., for the use of Architectural and
  Engineering Draughtsmen, Missal Painters, Masons, Decorative
  Painters, Lithographers, Engravers, Carvers, &c. &c. Collected
  and Engraved by F. DELAMOTTE, and printed in Colours. New and
  Cheaper Edition. Royal 8vo, oblong, 2_s._ 6_d._ ornamental boards.

  "For those who insert enamelled sentences round gilded chalices,
  who blazon shop legends over shop-doors, who letter church walls
  with pithy sentences from the Decalogue, this book will be
  useful."--_Athenæum._

  _EXAMPLES OF MODERN ALPHABETS, Plain and Ornamental_; including
  German, Old English, Saxon, Italic, Perspective, Greek, Hebrew,
  Court Hand, Engrossing, Tuscan, Riband, Gothic, Rustic, and
  Arabesque; with several Original Designs, and an Analysis of the
  Roman and Old English Alphabets, large and small, and Numerals,
  for the use of Draughtsmen, Surveyors, Masons, Decorative
  Painters, Lithographers, Engravers, Carvers, &c. Collected and
  Engraved by F. DELAMOTTE, and printed in Colours. New and Cheaper
  Edition. Royal 8vo, oblong, 2_s._ 6_d._ ornamental boards.

  "There is comprised in it every possible shape into which the
  letters of the alphabet and numerals can be formed, and the
  talent which has been expended in the conception of the various
  plain and ornamental letters is wonderful."--_Standard._

  _MEDIÆVAL ALPHABETS AND INITIALS FOR ILLUMINATORS._ By F. G.
  DELAMOTTE. Containing 21 Plates and Illuminated Title, printed
  in Gold and Colours. With an Introduction by J. WILLIS BROOKS.
  Fourth and Cheaper Edition. Small 4to, 4_s._ ornamental boards.

  "A volume in which the letters of the alphabet come forth
  glorified in gilding and all the colours of the prism interwoven
  and intertwined and intermingled."--_Sun._

  _THE EMBROIDERER'S BOOK OF DESIGN._ Containing Initials, Emblems,
  Cyphers, Monograms, Ornamental Borders, Ecclesiastical Devices,
  Mediæval and Modern Alphabets, and National Emblems. Collected
  by F. DELAMOTTE, and printed in Colours. Oblong royal 8vo, 1_s._
  6_d._ ornamental wrapper.

  "The book will be of great assistance to ladies and young
  children who are endowed with the art of plying the needle in
  this most ornamental and useful pretty work."--_East Anglian
  Times._


_=Wood Carving.=_

  _INSTRUCTIONS IN WOOD-CARVING, for Amateurs_: with Hints on
  Design. By A LADY. With Ten Plates. New and Cheaper Edition.
  Crown 8vo, 2_s._ in emblematic wrapper.

  "The handicraft of the wood-carver, so well as a book can impart
  it, may be learnt from 'A Lady's' publication."--_Athenæum._


NATURAL SCIENCE, etc.


_=The Heavens and their Origin.=_

  _THE VISIBLE UNIVERSE_: Chapters on the Origin and Construction
  of the Heavens. By J. E. GORE, F.R.A.S., Author of "Star Groups,"
  &c. Illustrated by 6 Stellar Photographs and 12 Plates. Demy 8vo,
  16_s._ cloth, gilt top.

  "A valuable and lucid summary of recent astronomical theory,
  rendered more valuable and attractive by a series of stellar
  photographs and other illustrations."--_The Times._

  "In presenting a clear and concise account of the present state
  of our knowledge, Mr. Gore has made a valuable addition to the
  literature of the subject."--_Nature._

  "One of the finest works on astronomical science that has
  recently appeared in our language. In spirit and in method it
  is scientific from cover to cover, but the style is so clear
  and attractive that it will be as acceptable and as readable to
  those who make no scientific pretensions as to those who devote
  themselves specially to matters astronomical."--_Leeds Mercury._

  "As interesting as a novel, and instructive withal; the text
  being made still more luminous by stellar photographs and other
  illustrations.... A most valuable book."--_Manchester Examiner._


_=The Constellations.=_

  _STAR GROUPS: A Student's Guide to the Constellations._ By J.
  ELLARD GORE, F.R.A.S., M.R.I.A., &c., Author of "The Visible
  Universe," "The Scenery of the Heavens." With 30 Maps. Small 4to,
  5_s._ cloth, silvered.

  "A knowledge of the principal constellations visible in our
  latitudes may be easily acquired from the thirty maps and
  accompanying text contained in this work."--_Nature._

  "The volume contains thirty maps showing stars of the sixth
  magnitude--the usual naked-eye limit--and each is accompanied by
  a brief commentary, adapted to facilitate recognition and bring
  to notice objects of special interest. For the purpose of a
  preliminary survey of the midnight pomp of the heavens, nothing
  could be better than a set of delineations averaging scarcely
  twenty square inches in area, and including nothing that cannot
  at once be identified."--_Saturday Review._

  "A very compact and handy guide to the
  constellations."--_Athenæum._


_=Astronomical Terms.=_

  _AN ASTRONOMICAL GLOSSARY_; or, Dictionary of Terms used in
  Astronomy. With Tables of Data and Lists of Remarkable and
  Interesting Celestial Objects. By J. ELLARD GORE, F.R.A.S.,
  Author of "The Visible Universe," &c. Small crown 8vo, 2_s._
  6_d._ cloth.

  "A very useful little work for beginners in astronomy, and not to
  be despised by more advanced students."--_The Times._

  "A very handy book ... the utility of which is much increased by
  its valuable tables of astronomical data."--_The Athenæum._

  "Astronomers of all kinds will be glad to have it for
  reference."--_Guardian._


_=The Microscope.=_

  _THE MICROSCOPE_: Its Construction and Management, including
  Technique, Photo-micrography, and the Past and Future of the
  Microscope. By Dr. HENRI VAN HEURCK, Director of the Antwerp
  Botannical Gardens. English Edition, Re-Edited and Augmented by
  the Author from the Fourth French Edition, and Translated by
  WYNNE E. BAXTER, F.R.M.S., F.G.S., &c. About 400 pages, with
  Three Plates and upwards of 250 Woodcuts. Imp. 8vo, 18_s._ cloth
  gilt.

  "A translation of a well-known work, at once popular and
  comprehensive."--_Times._

  "The translation is as felicitious as it is accurate."--_Nature._


_=Astronomy.=_

  _ASTRONOMY._ By the late Rev. ROBERT MAIN, M.A., F.R.S. Third
  Edition, Revised, by WM. THYNNE LYNN, B.A., F.R.A.S., formerly of
  the Royal Observatory, Greenwich, 12mo, 2_s._ cloth limp.

  "A sound and simple treatise, and a capital book for
  beginners."--_Knowledge._

  "Accurately brought down to the requirements of the present
  time."--_Educational Times._


_=Recent and Fossil Shells.=_

  _A MANUAL OF THE MOLLUSCA: Being a Treatise on Recent and Fossil
  Shells._ By S. P. WOODWARD, A.L.S., F.G.S., late Assistant
  Palæontologist in the British Museum. With an Appendix on _Recent
  and Fossil Conchological Discoveries_, by RALPH TATE, A.L.S.,
  F.G.S. Illustrated by A. N. WATERHOUSE and JOSEPH WILSON LOWRY.
  With 23 Plates and upwards of 300 Woodcuts. Reprint of Fourth
  Ed., 1880. Cr. 8vo, 7_s._ 6_d._ cl.

  "A most valuable storehouse of conchological and geological
  information."--_Science Gossip._


_=Geology and Genesis.=_

  _THE TWIN RECORDS OF CREATION; or, Geology and Genesis: their
  Perfect Harmony and Wonderful Concord._ By GEORGE W. VICTOR LE
  VAUX. Fcap. 8vo, 5_s._ cloth.

  "A valuable contribution to the evidences of Revelation, and
  disposes very conclusively of the arguments of those who would
  set God's Works against God's Word. No real difficulty is shirked
  and no sophistry is left unexposed."--_The Rock._


_DR. LARDNER'S COURSE OF NATURAL PHILOSOPHY._

  _THE HANDBOOK OF MECHANICS._ Enlarged and almost Rewritten by
  BENJAMIN LOEWY, F.R.A.S. With 378 Illustrations. Post 8vo, 6_s._
  cloth.

  "The perspicuity of the original has been retained, and chapters
  which had become obsolete have been replaced by others of more
  modern character. The explanations throughout are studiously
  popular, and care has been taken to show the application of the
  various branches of physics to the industrial arts, and to the
  practical business of life."--_Mining Journal._

  "Mr. Loewy has carefully revised the book, and brought it up to
  modern requirements."--_Nature._

  "Natural philosophy has had few exponents more able or better
  skilled in the art of popularising the subject than Dr.
  Lardner; and Mr. Loewy is doing good service in fitting this
  treatise, and the others of the series, for use at the present
  time."--_Scotsman._

  _THE HANDBOOK OF HYDROSTATICS AND PNEUMATICS._ New Edition,
  Revised and Enlarged, by BENJAMIN LOEWY, F.R.A.S. With 236
  Illustrations. Post 8vo, 5_s._ cloth.

  "For those 'who desire to attain an accurate knowledge of
  physical science without the profound methods of mathematical
  investigation,' this work is not merely intended, but well
  adapted."--_Chemical News._

  "The volume before us has been carefully edited, augmented
  to nearly twice the bulk of the former edition, and all
  the most recent matter has been added.... It is a valuable
  text-book."--_Nature._

  "Candidates for pass examinations will find it, we think,
  specially suited to their requirements."--_English Mechanic._

  _THE HANDBOOK OF HEAT._ Edited and almost entirely Rewritten by
  BENJAMIN LOEWY, F.R.A.S., &c. 117 Illusts. Post 8vo, 6_s._ cloth.

  "The style is always clear and precise, and conveys
  instruction without leaving any cloudiness or lurking doubts
  behind."--_Engineering._

  "A most exhaustive book on the subject on which it treats, and
  is so arranged that it can be understood by all who desire to
  attain an accurate knowledge of physical science.... Mr. Loewy
  has included all the latest discoveries in the varied laws and
  effects of heat."--_Standard._

  "A complete and handy text-book for the use of students and
  general readers."--_English Mechanic._

  _THE HANDBOOK OF OPTICS._ By DIONYSIUS LARDNER, D.C.L., formerly
  Professor of Natural Philosophy and Astronomy in University
  College, London. New Edition. Edited by T. OLVER HARDING, B.A.
  Lond., of University College, London. With 298 Illustrations.
  Small 8vo, 448 pages, 5_s._ cloth.

  "Written by one of the ablest English scientific writers,
  beautifully and elaborately illustrated."--_Mechanic's Magazine._

  _THE HANDBOOK OF ELECTRICITY, MAGNETISM, AND ACOUSTICS._ By Dr.
  LARDNER. Ninth Thousand. Edit. by GEORGE CAREY FOSTER, B.A.,
  F.C.S. With 400 Illustrations. Small 8vo, 5_s._ cloth.

  "The book could not have been entrusted to anyone better
  calculated to preserve the terse and lucid style of Lardner,
  while correcting his errors and bringing up his work to the
  present state of scientific knowledge."--_Popular Science Review._

  _THE HANDBOOK OF ASTRONOMY._ Forming a Companion to the "Handbook
  of Natural Philosophy." By DIONYSIUS LARDNER, D.C.L., formerly
  Professor of Natural Philosophy and Astronomy in University
  College, London. Fourth Edition, Revised and Edited by EDWIN
  DUNKIN, F.R.A.S., Royal Observatory, Greenwich. With 38 Plates
  and upwards of 100 Woodcuts. In One Vol., small 8vo, 550 pages,
  9_s._ 6_d._ cloth.

  "Probably no other book contains the same amount of information
  in so compendious and well-arranged a form--certainly none at the
  price at which this is offered to the public."--_Athenæum._

  "We can do no other than pronounce this work a most valuable
  manual of astronomy, and we strongly recommend it to all who wish
  to acquire a general--but at the same time correct--acquaintance
  with this sublime science."--_Quarterly Journal of Science._

  "One of the most deservedly popular books on the subject.... We
  would recommend not only the student of the elementary principles
  of the science, but he who aims at mastering the higher and
  mathematical branches of astronomy, not to be without this work
  beside him."--_Practical Magazine._


_=Geology.=_

  _RUDIMENTARY TREATISE ON GEOLOGY, PHYSICAL AND HISTORICAL._
  Consisting of "Physical Geology," which sets forth the leading
  Principles of the Science; and "Historical Geology," which treats
  of the Mineral and Organic Conditions of the Earth at each
  successive epoch, especial reference being made to the British
  Series of Rocks. By RALPH TATE, A.L.S., F.G.S., &c. With 250
  Illustrations. 12mo, 5_s._ cl. bds.

  "The fulness of the matter has elevated the book into a manual.
  Its information is exhaustive and well arranged."--_School Board
  Chronicle._


_DR. LARDNER'S MUSEUM OF SCIENCE AND ART._

  _THE MUSEUM OF SCIENCE AND ART._ Edited by DIONYSIUS LARDNER,
  D.C.L., formerly Professor of Natural Philosophy and Astronomy in
  University College, London. With upwards of 1,200 Engravings on
  Wood. In 6 Double Volumes, £1 1_s._ in a new and elegant cloth
  binding; or handsomely bound in half-morocco, 31_s._ 6_d._

*** OPINIONS OF THE PRESS.

  "This series, besides affording popular but sound instruction
  on scientific subjects, with which the humblest man in the
  country ought to be acquainted, also undertakes that teaching
  of 'Common Things' which every well-wisher of his kind is
  anxious to promote. Many thousand copies of this serviceable
  publication have been printed, in the belief and hope that the
  desire for instruction and improvement widely prevails; and
  we have no fear that such enlightened faith will meet with
  disappointment."--_Times._

  "A cheap and interesting publication, alike informing and
  attractive. The papers combine subjects of importance and great
  scientific knowledge, considerable inductive powers, and a
  popular style of treatment."--_Spectator._

  "The 'Museum of Science and Art' is the most valuable
  contribution that has ever been made to the Scientific
  Instruction of every class of society."--Sir DAVID BREWSTER, in
  the _North British Review_.

  "Whether we consider the liberality and beauty of the
  illustrations, the charm of the writing, or the durable interest
  of the matter, we must express our belief that there is hardly to
  be found among the new books one that would be welcomed by people
  of so many ages and classes as a valuable present."--_Examiner._

*** _Separate books formed from the above, suitable for Workmen's
Libraries, Science Classes, etc._

  _=Common Things Explained.=_ Containing Air, Earth, Fire, Water,
  Time, Man, the Eye, Locomotion, Colour, Clocks and Watches, &c.
  233 Illustrations, cloth gilt, 5_s._

  _=The Microscope.=_ Containing Optical Images, Magnifying
  Glasses, Origin and Description of the Microscope, Microscopic
  Objects, the Solar Microscope, Microscopic Drawing and Engraving,
  &c. 147 Illustrations, cloth gilt, 2_s._

  _=Popular Geology.=_ Containing Earthquakes and Volcanoes, the
  Crust of the Earth, &c. 201 Illustrations, cloth gilt, 2_s._ 6_d._

  _=Popular Physics.=_ Containing Magnitude and Minuteness,
  the Atmosphere, Meteoric Stones, Popular Fallacies, Weather
  Prognostics, the Thermometer, the Barometer, Sound, &c. 85
  Illustrations, cloth gilt, 2_s._ 6_d._

  _=Steam, and its Uses.=_ Including the Steam Engine, the
  Locomotive, and Steam Navigation. 89 Illustrations, cloth gilt,
  2_s._

  _=Popular Astronomy.=_ Containing How to observe the Heavens--The
  Earth, Sun, Moon, Planets, Light, Comets, Eclipses, Astronomical
  Influences, &c. 182 Illustrations, cloth gilt, 4_s._ 6_d._

  _=The Bee and White Ants=_: Their Manners and Habits. With
  Illustrations of Animal Instinct and Intelligence. 135
  Illustrations, cloth gilt, 2_s._

  _=The Electric Telegraph Popularised.=_ To render intelligible
  to all who can Read, irrespective of any previous Scientific
  Acquirements, the various forms of Telegraphy in Actual
  Operation. 100 Illustrations, cloth gilt, 1_s._ 6_d._


_=Dr. Lardner's School Handbooks.=_

  _NATURAL PHILOSOPHY FOR SCHOOLS._ By Dr. LARDNER. 328
  Illustrations. Sixth Edition. One Vol., 3_s._ 6_d._ cloth.

  "A very convenient class-book for junior students in private
  schools. It is intended to convey in clear and precise terms,
  general notions of all the principal divisions of Physical
  Science."--_British Quarterly Review._

  _ANIMAL PHYSIOLOGY FOR SCHOOLS._ By Dr. LARDNER. With 190
  Illustrations. Second Edition. One Vol., 3_s._ 6_d._ cloth.

  "Clearly written, well arranged, and excellently
  illustrated."--_Gardener's Chronicle._


_=Lardner and Bright on the Electric Telegraph.=_

  _THE ELECTRIC TELEGRAPH._ By Dr. LARDNER. Revised and Re-written
  by E. B. BRIGHT, F.R.A.S. 140 Illustrations. Small 8vo, 2_s._
  6_d._ cloth.

  "One of the most readable books extant on the Electric
  Telegraph."--_English Mechanic._


CHEMICAL MANUFACTURES, CHEMISTRY.


_=Chemistry for Engineers, etc.=_

  _ENGINEERING CHEMISTRY_; A Practical Treatise for the Use of
  Analytical Chemists, Engineers, Iron Masters, Iron Founders,
  Students, and others. Comprising Methods of Analysis and
  Valuation of the Principal Materials used in Engineering Work,
  with numerous Analyses, Examples, and Suggestions. By H. JOSHUA
  PHILLIPS, F.I.C., F.C.S. formerly Analytical and Consulting
  Chemist to the Great Eastern Railway. Second Edition, Revised and
  Enlarged. Crown 8vo, 400 pp., with Illustrations, 10_s._ 6_d._
  cloth.

  [_Just published._

  "In this work the author has rendered no small service to a
  numerous body of practical men.... The analytical methods may be
  pronounced most satisfactory, being as accurate as the despatch
  required of engineering chemists permits."--_Chemical News._

  "Those in search of a handy treatise on the subject of analytical
  chemistry as applied to the every-day requirements of workshop
  practice will find this volume of great assistance."--_Iron._

  "The first attempt to bring forward a Chemistry specially written
  for the use of engineers, and we have no hesitation whatever
  in saying that it should at once be in the possession of every
  railway engineer."--_The Railway Engineer._

  "The book will be very useful to those who require a handy and
  concise _resume_ of approved methods of analysing and valuing
  metals, oils, fuels, &c. It is, in fact, a work for chemists, a
  guide to the routine of the engineering laboratory.... The book
  is full of good things. As a handbook of technical analysis, it
  is very welcome."--_Builder._

  "Considering the extensive ground which such a subject as
  Engineering Chemistry covers, the work is complete, and
  recommends itself to both the practising analyist and the
  analytical student."--_Chemical Trade Journal._

  "The analytical methods given are, as a whole, such as are likely
  to give rapid and trustworthy results in experienced hands. There
  is much excellent descriptive matter in the work, the chapter
  on 'Oils and Lubrication' being specially noticeable in this
  respect."--_Engineer._


_=Alkali Trade, Manufacture of Sulphuric Acid, etc.=_

  _A MANUAL OF THE ALKALI TRADE_, including the Manufacture of
  Sulphuric Acid, Sulphate of Soda, and Bleaching Powder. By JOHN
  LOMAS, Alkali Manufacturer, Newcastle-upon-Tyne and London. With
  232 Illustrations and Working Drawings, and containing 390 pages
  of Text. Second Edition, with Additions. Super-royal 8vo, £1
  10_s._ cloth.

  "This book is written by a manufacturer for manufacturers.
  The working details of the most approved forms of apparatus
  are given, and these are accompanied by no less than 232
  wood engravings, all of which may be used for the purposes
  of construction. Every step in the manufacture is very
  fully described in this manual, and each improvement
  explained."--_Athenæum._

  "We find not merely a sound and luminous explanation of the
  chemical principles of the trade, but a notice of numerous
  matters which have a most important bearing on the successful
  conduct of alkali works, but which are generally overlooked by
  even experienced technological authors."--_Chemical Review._


_=The Blowpipe.=_

  _THE BLOWPIPE IN CHEMISTRY, MINERALOGY, AND GEOLOGY._ Containing
  all known Methods of Anhydrous Analysis, many Working Examples,
  and Instructions for Making Apparatus. By Lieut.-Colonel W.
  A. ROSS, R.A., F.G.S. With 120 Illustrations. Second Edition,
  Revised and Enlarged. Crown 8vo, 5_s._ cloth.

  "The student who goes through the course of experimentation
  here laid down will gain a better insight into inorganic
  chemistry and mineralogy than if he had 'got up' any of the
  best text-books, and passed any number of examinations in their
  contents."--_Chemical News._


_=Commercial Chemical Analysis.=_

  _THE COMMERCIAL HANDBOOK OF CHEMICAL ANALYSIS_; or, Practical
  Instructions for the determination of the Intrinsic or Commercial
  Value of Substances used in Manufactures, in Trades, and in the
  Arts. By A. NORMANDY, Editor of Rose's "Treatise on Chemical
  Analysis." New Edition, to a great extent Re-written by HENRY
  M. NOAD, Ph.D., F.R.S. With numerous Illustrations. Crown 8vo,
  12_s._ 6_d._ cloth.

  "We strongly recommend this book to our readers as a guide,
  alike indispensable to the housewife as to the pharmaceutical
  practitioner."--_Medical Times._

  "Essential to the analysts appointed under the new Act. The
  most recent results are given and the work is well edited and
  carefully written."--_Nature._


_=Dye-Wares and Colours.=_

  _THE MANUAL OF COLOURS AND DYE-WARES_: Their Properties,
  Applications, Valuations, Impurities, and Sophistications. For
  the use of Dyers, Printers, Drysalters, Brokers, &c. By J. W.
  SLATER. Second Edition, Revised and greatly Enlarged. Crown 8vo,
  7_s._ 6_d._ cloth.

  "A complete encyclopædia of the _materia tinctoria_. The
  information given respecting each article is full and precise,
  and the methods of determining the value of articles such as
  these, so liable to sophistication, are given with clearness, and
  are practical as well as valuable."--_Chemist and Druggist._

  "There is no other work which covers precisely the same ground.
  To students preparing for examinations in dyeing and printing it
  will prove exceedingly useful."--_Chemical News._


_=Modern Brewing and Malting.=_

  _A HANDYBOOK FOR BREWERS_: Being a Practical Guide to the Art of
  Brewing and Malting. Embracing the Conclusions of Modern Research
  which bear upon the Practice of Brewing. By HERBERT EDWARDS
  WRIGHT, M.A., Author of "A Handbook for Young Brewers." Crown
  8vo, 530 pp., 12_s._ 6_d._ cloth.

  "May be consulted with advantage by the student who is preparing
  himself for examinational tests, while the scientific brewer
  will find in it a _resume_ of all the most important discoveries
  of modern times. The work is written throughout in a clear and
  concise manner, and the author takes great care to discriminate
  between vague theories and well-established facts."--_Brewers'
  Journal._

  "We have great pleasure in recommending this handybook, and have
  no hesitation in saying that it is one of the best--if not the
  best--which has yet been written on the subject of beer-brewing
  in this country, and it should have a place on the shelves of
  every brewer's library."--_The Brewer's Guardian._

  "Although the requirements of the student are primarily
  considered, an acquaintance of half-an-hour's duration cannot
  fail to impress the practical brewer with the sense of having
  found a trustworthy guide and practical counsellor in brewery
  matters."--_Chemical Trade Journal._


_=Analysis and Valuation of Fuels.=_

  _FUELS: SOLID, LIQUID, AND GASEOUS_, Their Analysis and
  Valuation. For the Use of Chemists and Engineers. By H. J.
  PHILLIPS, F.C.S., formerly Analytical and Consulting Chemist to
  the Great Eastern Railway. Second Edition, Revised and Enlarged.
  Crown 8vo, 5_s._ cloth.

  "Ought to have its place in the laboratory of every metallurgical
  establishment, and wherever fuel is used on a large
  scale."--_Chemical News._

  "Cannot fail to be of wide interest, especially at the present
  time."--_Railway News._


_=Pigments.=_

  _THE ARTIST'S MANUAL OF PIGMENTS._ Showing their Composition,
  Conditions of Permanency, Non-Permanency, and Adulterations;
  Effects in Combination with Each Other and with Vehicles; and
  the most Reliable Tests of Purity Together with the Science and
  Art Department's Examination Questions on Painting. By H. C.
  STANDAGE. Second Edition. Crown 8vo, 2_s._ 6_d._ cloth.

  "This work is indeed _multum-in-parvo_, and we can, with good
  conscience, recommend it to all who come in contact with
  pigments, whether as makers, dealers or users."--_Chemical
  Review._


_=Gauging. Tables and Rules for Revenue Officers, Brewers, etc.=_

  _A POCKET BOOK OF MENSURATION AND GAUGING_: Containing Tables,
  Rules and Memoranda for Revenue Officers, Brewers, Spirit
  Merchants, &c. By J. B. MANT (Inland Revenue). Second Edition,
  Revised. 18mo, 4_s._ leather.

  "This handy and useful book is adapted to the requirements of
  the Inland Revenue Department, and will be a favourite book
  of reference. The range of subjects is comprehensive, and the
  arrangement simple and clear."--_Civilian._

  "Should be in the hands of every practical brewer."--_Brewers'
  Journal._


INDUSTRIAL ARTS, TRADES, AND MANUFACTURES.


_=Cotton Spinning.=_

  _COTTON MANUFACTURE_: A Practical Manual. Embracing the various
  operations of Cotton Manufacture, Dyeing, &c. For the Use of
  Operatives, Overlookers, and Manufacturers. By JOHN LISTER,
  Technical Instructor, Pendleton. With numerous Illustrations.
  Demy 8vo, 7_s._ 6_d._ cloth.

  [_Just published._


_=Flour Manufacture, Milling, etc.=_

  _FLOUR MANUFACTURE_: A Treatise on Milling Science and
  Practice. By FRIEDRICH KICK, Imperial Regierungsrath, Professor
  of Mechanical Technology in the Imperial German Polytechnic
  Institute, Prague. Translated from the Second Enlarged and
  Revised Edition with Supplement. By H. H. P. POWLES, Assoc. Memb.
  Institution of Civil Engineers. Nearly 400 pp. Illustrated with
  28 Folding Plates, and 167 Woodcuts. Royal 8vo, 25_s._ cloth.

  "This valuable work is, and will remain, the standard authority
  on the science of milling.... The miller who has read and
  digested this work will have laid the foundation, so to speak, of
  a successful career; he will have acquired a number of general
  principles which he can proceed to apply. In this handsome volume
  we at last have the accepted text-book of modern milling in good,
  sound English, which has little, if any, trace of the German
  idiom."--_The Miller._

  "The appearance of this celebrated work in English is very
  opportune, and British millers will, we are sure, not be slow in
  availing themselves of its pages."--_Millers' Gazette._


_=Agglutinants.=_

  _CEMENTS, PASTES, GLUES AND GUMS_: A Practical Guide to the
  Manufacture and Application of the various Agglutinants required
  in the Building, Metal-Working, Wood-Working and Leather-Working
  Trades, and for Workshop, Laboratory or Office Use. With upwards
  of 900 Recipes and Formulæ. By H. C. STANDAGE, Chemist. Crown
  8vo, 2_s._ 6_d._ cloth.

  [_Just published._

  "We have pleasure in speaking favourably of this volume. So far
  as we have had experience, which is not inconsiderable, this
  manual is trustworthy."--_Athenæum._

  "As a revelation of what are considered trade secrets, this book
  will arouse an amount of curiosity among the large number of
  industries it touches."--_Daily Chronicle._

  "In this goodly collection of receipts it would be strange if a
  cement for any purpose cannot be found."--_Oil and Colourman's
  Journal._


_=Soap-making.=_

  _THE ART OF SOAP-MAKING: A Practical Handbook of the Manufacture
  of Hard and Soft Soaps, Toilet Soaps, etc._ Including many New
  Processes, and a Chapter on the Recovery of Glycerine from Waste
  Leys. By ALEXANDER WATT. Fourth Edition, Enlarged. Crown 8vo,
  7_s._ 6_d._ cloth.

  "The work will prove very useful, not merely to the technological
  student, but to the practical soap-boiler who wishes to
  understand the theory of his art."--_Chemical News._

  "A thoroughly practical treatise on an art which has almost no
  literature in our language. We congratulate the author on the
  success of his endeavour to fill a void in English technical
  literature."--_Nature._


_=Paper Making.=_

  _PRACTICAL PAPER-MAKING_: A Manual for Paper-makers and Owners
  and Managers of Paper-Mills. With Tables, Calculations, &c. By
  G. CLAPPERTON, Paper-maker. With Illustrations of Fibres from
  Micro-Photographs. Crown 8vo, 5_s._ cloth.

  [_Just published._

  "The author caters for the requirements of responsible mill
  hands, apprentices, &c., whilst his manual will be found of great
  service to students of technology, as well as to veteran paper
  makers and mill owners. The illustrations form an excellent
  feature."--_Paper Trade Review._

  "We recommend everybody interested in the trade to get a copy of
  this thoroughly practical book."--_Paper Making._


_=Paper Making.=_

  _THE ART OF PAPER MAKING: A Practical Handbook of the Manufacture
  of Paper from Rags, Esparto, Straw, and other Fibrous Materials._
  Including the Manufacture of Pulp from Wood Fibre, with a
  Description of the Machinery and Appliances used. To which
  are added Details of Processes for Recovering Soda from Waste
  Liquors. By ALEXANDER WATT, Author of "The Art of Soap-Making"
  With Illusts. Crown 8vo, 7_s_. 6_d._ cloth.

  "It may be regarded as the standard work on the subject. The book
  is full of valuable information. The 'Art of Paper-making,' is
  in every respect a model of a text-book, either for a technical
  class or for the private student."--_Paper and Printing Trades
  journal._


_=Leather Manufacture.=_

  _THE ART OF LEATHER MANUFACTURE._ Being a Practical Handbook, in
  which the Operations of Tanning, Currying, and Leather Dressing
  are fully Described, and the Principles of Tanning Explained,
  and many Recent Processes Introduced; as also the Methods for
  the Estimation of Tannin, and a Description of the Arts of
  Glue Boiling, Gut Dressing, &c. By ALEXANDER WATT, Author of
  "Soap-Making," &c. Second Edition. Crown 8vo, 9_s._ cloth.

  "A sound, comprehensive treatise on tanning and its accessories.
  It is an eminently valuable production, which redounds to the
  credit of both author and publishers."--_Chemical Review._


_=Boot and Shoe Making.=_

  _THE ART OF BOOT AND SHOE-MAKING._ A Practical Handbook,
  including Measurement, Last-Fitting, Cutting-Out, Closing,
  and Making, with a Description of the most approved Machinery
  employed. By JOHN B. LENO, late Editor of _St. Crispin_, and _The
  Boot and Shoe-Maker_. 12mo, 2_s._ cloth limp.

  "This excellent treatise is by far the best work ever written.
  The chapter on clicking, which shows how waste may be prevented,
  will save fifty times the price of the book."--_Scottish Leather
  Trader._


_=Dentistry Construction.=_

  _MECHANICAL DENTISTRY: A Practical Treatise on the Construction
  of the various kinds of Artificial Dentures._ Comprising also
  Useful Formulæ, Tables, and Receipts for Gold Plate, Clasps,
  Solders, &c. &c. By CHARLES HUNTER. Third Edition. Crown 8vo,
  3_s._ 6_d._ cloth.

  "We can strongly recommend Mr. Hunter's treatise to all students
  preparing for the profession of dentistry, as well as to every
  mechanical dentist."--_Dublin Journal of Medical Science._


_=Wood Engraving.=_

  _WOOD ENGRAVING: A Practical and Easy Introduction to the Study
  of the Art._ By WILLIAM NORMAN BROWN. Second Edition. With
  numerous Illustrations. 12mo, 1_s._ 6_d._ cloth limp.

  "The book is clear and complete, and will be useful to anyone
  wanting to understand the first elements of the beautiful art of
  wood engraving."--_Graphic._


_=Horology.=_

  _A TREATISE ON MODERN HOROLOGY, in Theory and Practice._
  Translated from the French of CLAUDIUS SAUNIER, ex-Director of
  the School of Horology at Maçon, by JULIEN TRIPPLIN, F.R A.S.,
  Besançon Watch Manufacturer, and EDWARD RIGG, M.A., Assayer in
  the Royal Mint. With 78 Woodcuts and 22 Coloured Copper Plates.
  Second Edition. Super-royal 8vo, £2 2_s._ cloth; £2 10_s._
  half-calf.

  "There is no horological work in the English language at all to
  be compared to this production of M. Saunier's for clearness
  and completeness. It is alike good as a guide for the student
  and as a reference for the experienced horolegist and skilled
  workman."--_Horological Journal._

  "The latest, the most complete, and the most reliable of
  those literary productions to which continental watchmakers
  are indebted for the mechanical superiority over their
  English brethren--in fact, the Book of Books, is M. Saunier's
  'Treatise.'"--_Watchmaker, Jeweller and Silversmith._


_=Watchmaking.=_

  _THE WATCHMAKER'S HANDBOOK._ Intended as a Workshop Companion
  for those engaged in Watchmaking and the Allied Mechanical Arts.
  Translated from the French of CLAUDIUS SAUNIER, and considerably
  enlarged by JULIEN TRIPPLIN, F.R.A.S., Vice-President of the
  Horological Institute, and EDWARD RIGG, M.A., Assayer in the
  Royal Mint. With numerous Woodcuts and 14 Copper Plates. Third
  Edition. Crown 8vo, 9_s._ cloth.

  "Each part is truly a treatise in itself. The arrangement is good
  and the language is clear and concise. It is an admirable guide
  for the young watchmaker."--_Engineering._

  "It is impossible to speak too highly of its excellence. It
  fulfils every requirement in a handbook intended for the use
  of a workman. Should be found in every workshop."--_Watch and
  Clockmaker._

  "This book contains an immense number of practical details
  bearing on the daily occupation of a watchmaker."--_Watchmaker
  and Metalworker_ (Chicago).


_=Watches and Timekeepers.=_

  _A HISTORY OF WATCHES AND OTHER TIMEKEEPERS._ By JAMES F. KENDAL,
  M.B.H.Inst. 1_s._ 6_d._ boards; or 2_s._ 6_d._ cloth gilt.

  "Mr. Kendal's book, for its size, is the best which has yet
  appeared on this subject in the English language."--_Industries._

  "Open the book where you may, there is interesting matter in
  it concerning the ingenious devices of the ancient or modern
  horologer. The subject is treated in a liberal and entertaining
  spirit, as might be expected of a historian who is a master of
  the craft."--_Saturday Review._


_=Electrolysis of Gold, Silver, Copper, etc.=_

  _ELECTRO-DEPOSITION: A Practical Treatise on the Electrolysis
  of Gold, Silver, Copper, Nickel, and other Metals and
  Alloys._ With descriptions of Voltaic Batteries, Magneto and
  Dynamo-Electric Machines, Thermopiles, and of the Materials
  and Processes used in every Department of the Art, and several
  Chapters on Electro-Metallurgy. By ALEXANDER WATT, Author of
  "Electro-Metallurgy," &c. Third Edition,Revised. Crown 8vo, 9_s._
  cloth.

  "Eminently a book for the practical worker in electro-deposition.
  It contains practical descriptions of methods, processes
  and materials as actually pursued and used in the
  workshop."--ENGINEER.


_=Electro-Metallurgy.=_

  _ELECTRO-METALLURGY: Practically Treated._ By ALEXANDER WATT,
  Author of "Electro-Deposition," &c. Ninth Edition, including the
  most recent Processes. 12mo, 4_s._ cloth boards.

  "From this book both amateur and artisan may learn
  everything necessary for the successful prosecution of
  electroplating."--_Iron._


_=Working in Gold.=_

  _THE JEWELLER'S ASSISTANT IN THE ART OF WORKING IN GOLD_: A
  Practical Treatise for Masters and Workmen, Compiled from the
  Experience of Thirty Years' Workshop Practice. By GEORGE E. GEE,
  Author of "The Goldsmith's Handbook," &c. Cr. 8vo, 7_s._ 6_d._
  cloth.

  "This manual of technical education is apparently destined to be
  a valuable auxiliary to a handicraft which is certainty capable
  of great improvement."--_The Times._

  "Very useful in the workshop, as the knowledge is practical,
  having been acquired by long experience, and all the recipes
  and directions are guaranteed to be successful."--_Jeweller and
  Metalworker._


_=Electroplating.=_

  _ELECTROPLATING_: A Practical Handbook on the Deposition of
  Copper, Silver, Nickel, Gold, Aluminium, Brass, Platinum, &c. &c.
  With Descriptions of the Chemicals, Materials, Batteries, and
  Dynamo Machines used in the Art. By J. W. URQUHART, C.E., Author
  of "Electric Light," &c. Third Edition, Revised, with Additions.
  Numerous Illustrations. Crown 8vo, 5_s._ cloth.

  "An excellent practical manual."--_Engineering._

  "An excellent work, giving the newest information."--_Horological
  Journal._


_=Electrotyping.=_

  _ELECTROTYPING: The Reproduction and Multiplication of Printing
  Surfaces and Works of Art by the Electro-deposition of Metals._
  By J. W. URQUHART, C.E. Crown 8vo, 5_s._ cloth.

  "The book is thoroughly practical. The reader is, therefore,
  conducted through the leading laws of electricity, then
  through the metals used by electrotypers, the apparatus, and
  the depositing processes, up to the final preparation of the
  work."--_Art Journal._


_=Goldsmiths' Work.=_

  _THE GOLDSMITH'S HANDBOOK._ By GEORGE E. GEE, Jeweller, &c. Third
  Edition, considerably Enlarged, 12mo, 3_s._ 6_d._ cl. bds.

  "A good, sound educator, and will be generally accepted as an
  authority."--_Horological Journal._


_=Silversmiths' Work.=_

  _THE SILVERSMITH'S HANDBOOK._ By GEORGE E. GEE, Jeweller, &c.
  Second Edition, Revised, with numerous Illustrations. 12mo, 3_s._
  6_d._ cloth boards.

  "The chief merit of the work is its practical character.... The
  workers in the trade will speedily discover its merits when they
  sit down to study it."--_English Mechanic._

*** _The above two-works together, strongly half-bound, price 7s._


_=Bread and Biscuit Baking.=_

  _THE BREAD AND BISCUIT BAKER'S AND SUGAR-BOILER'S ASSISTANT._
  Including a large variety of Modern Recipes. With Remarks on the
  Art of Bread-making. By ROBERT WELLS, Practical Baker. Second
  Edition, with Additional Recipes. Crown 8vo, 2_s._ cloth.

  "A large number of wrinkles for the ordinary cook, as well as the
  baker."--_Saturday Review._


_=Confectionery for Hotels and Restaurants.=_

  _THE PASTRYCOOK AND CONFECTIONER'S GUIDE._ For Hotels,
  Restaurants and the Trade in general, adapted also for Family
  Use. By ROBERT WELLS, Author of "The Bread and Biscuit Baker's
  and Sugar-Boiler's Assistant." Crown 8vo, 2_s._ cloth.

  "We cannot speak too highly of this really excellent work. In
  these days of keen competition our readers cannot do better than
  purchase this book."--_Bakers' Times._


_=Ornamental Confectionery.=_

  _ORNAMENTAL CONFECTIONERY_: A Guide for Bakers. Confectioners and
  Pastrycooks; including a variety of Modern Recipes, and Remarks
  on Decorative and Coloured Work. With 129 Original Designs. By
  ROBERT WELLS, Practical Baker, Author of "The Bread and Biscuit
  Baker's and Sugar-Boiler's Assistant," &c. Crown 8vo, cloth gilt,
  5_s._

  "A valuable work, practical, and should be in the hands of every
  baker and confectioner. The illustrative designs are alone worth
  treble the amount charged for the whole work."--_Bakers' Times._


_=Flour Confectionery.=_

  _THE MODERN FLOUR CONFECTIONER._ Wholesale and Retail. Containing
  a large Collection of Recipes for Cheap Cakes, Biscuits, &c. With
  Remarks on the Ingredients used in their Manufacture. To which
  are added Recipes for Dainties for the Working Man's Table. By R.
  WELLS, Author of "The Bread and Biscuit Baker," &c. Crown 8vo,
  2_s._ cl.

  "The work is of a decidedly practical character, and in every
  recipe regard is had to economical working."--_North British
  Daily Mail._


_=Laundry Work.=_

  _LAUNDRY MANAGEMENT._ A Handbook for Use in Private and Public
  Laundries, Including Descriptive Accounts of Modern Machinery
  and Appliances for Laundry Work. By the EDITOR of "The Laundry
  Journal." With numerous Illustrations. Second Edition. Crown 8vo,
  2_s._ 6_d._ cloth.

  "This book should certainly occupy an honoured place on the
  shelves of all housekeepers who wish to keep themselves _au
  courant_ of the newest appliances and methods."--_The Queen._


HANDYBOOKS FOR HANDICRAFTS.

By PAUL N. HASLUCK,

EDITOR OF "WORK" (NEW SERIES); AUTHOR OF "LATHEWORK," "MILLING
MACHINES," &c.

Crown 8vo, 144 pages, cloth, price 1_s._ each.

==> _These_ HANDYBOOKS _have been written to supply information
for_ WORKMEN, STUDENTS, _and_ AMATEURS _in the several Handicrafts,
on the actual_ PRACTICE _of the_ WORKSHOP, _and are intended to
convey in plain language_ TECHNICAL KNOWLEDGE _of the several_
CRAFTS. _In describing the processes employed, and the manipulation
of material, workshop terms are used; workshop practice is fully
explained; and the text is freely illustrated with drawings of
modern tools, appliances, and processes._


  _THE METAL TURNER'S HANDYBOOK. A Practical Manual for Workers at
  the Foot-Lathe._ With over 100 Illustrations. Price 1_s._

  "The book will be of service alike to the amateur and the
  artisan turner. It displays thorough knowledge of the
  subject."--_Scotsman._

  _THE WOOD TURNER'S HANDYBOOK. A Practical Manual for Workers at
  the Lathe._ With over 100 Illustrations. Price 1_s._

  "We recommend the book to young turners and amateurs. A multitude
  of workmen have hitherto sought in vain for a manual of this
  special industry."--_Mechanical World._

  _THE WATCH JOBBER'S HANDYBOOK. A Practical Manual on Cleaning,
  Repairing, and Adjusting._ With upwards of 100 Illustrations.
  Price 1_s._

  "We strongly advise all young persons connected with the watch
  trade to acquire and study this inexpensive work."--_Clerkenwell
  Chronicle._

  _THE PATTERN MAKER'S HANDYBOOK._ A Practical Manual on the
  Construction of Patterns for Founders. With upwards of 100
  Illustrations. Price 1_s._

  "A most valuable, if not indispensable, manual for the pattern
  maker."--_Knowledge._

  _THE MECHANIC'S WORKSHOP HANDYBOOK. A Practical Manual on
  Mechanical Manipulation._ Embracing Information on various
  Handicraft Processes, with Useful Notes and Miscellaneous
  Memoranda. Comprising about 200 Subjects. Price 1_s._

  "A very clever and useful book, which should be found in every
  workshop; and it should certainly find a place in all technical
  schools."--_Saturday Review._

  _THE MODEL ENGINEER'S HANDYBOOK. A Practical Manual on the
  Construction of Model Steam Engines._ With upwards of 100
  Illustrations. Price 1_s._

  "Mr. Hasluck has produced a very good little book."--_Builder._

  _THE CLOCK JOBBER'S HANDYBOOK. A Practical Manual on Cleaning,
  Repairing, and Adjusting._ With upwards of 100 Illustrations.
  Price 1_s._

  "It is of inestimable service to those commencing the
  trade."--_Coventry Standard._

  _THE CABINET WORKER'S HANDYBOOK_: A Practical Manual on the
  Tools, Materials, Appliances, and Processes employed in Cabinet
  Work. With upwards of 100 Illustrations. Price 1_s._

  "Mr. Hasluck's thoroughgoing little Handybook is amongst
  the most practical guides we have seen for beginners in
  cabinet-work."--_Saturday Review._

  _THE WOODWORKER'S HANDYBOOK OF MANUAL INSTRUCTION._ Embracing
  Information on the Tools, Materials, Appliances and Processes
  employed in Woodworking. With 104 Illustrations. Price 1_s._

  [_Just published._

  _THE METALWORKER'S HANDYBOOK._ With upwards of 100 Illustrations.

  [_In preparation._

*** OPINIONS OF THE PRESS.

  "Written by a man who knows, not only how work ought to be
  done, but how to do it, and how to convey his knowledge to
  others."--_Engineering._

  "Mr. Hasluck writes admirably, and gives complete
  instructions."--_Engineer._

  "Mr. Hasluck combines the experience of a practical teacher with
  the manipulative skill and scientific knowledge of processes of
  the trained mechanician, and the manuals are marvels of what can
  be produced at a popular price."--_Schoolmaster._

  "Helpful to workmen of all ages and degrees of
  experience."--_Daily Chronicle._

  "Practical, sensible, and remarkably cheap."--_Journal of
  Education._

  "Concise, clear and practical."--_Saturday Review._


COMMERCE, COUNTING-HOUSE WORK, TABLES, etc.


_=Commercial Education.=_

  _LESSONS IN COMMERCE._ By Professor R. GAMBARO, of the Royal High
  Commercial School at Genoa. Edited and Revised by JAMES GAULT,
  Professor of Commerce and Commercial Law in King's College,
  London. Crown 8vo, 3_s._ 6_d._ cloth.

  "The publishers of this work have rendered considerable service
  to the cause of commercial education by the opportune production
  of this volume.... The work is peculiarly acceptable to English
  readers and an admirable addition to existing class-books. In
  a phrase, we think the work attains its object in furnishing
  a brief account of those laws and customs of British trade
  with which the commercial man interested therein should be
  familiar."--_Chamber of Commerce Journal._

  "An invaluable guide in the hands of those who are preparing for
  a commercial career."--_Counting House._


_=Foreign Commercial Correspondence.=_

  _THE FOREIGN COMMERCIAL CORRESPONDENT_: Being Aids to Commercial
  Correspondence in Five Languages--English, French, German,
  Italian, and Spanish. By CONRAD E. BAKER. Second Edition. Crown
  8vo, 3_s._ 6_d._ cloth.

  "Whoever wishes to correspond in all the languages mentioned by
  Mr. Baker cannot do better than study this work, the materials of
  which are excellent and conveniently arranged. They consist not
  of entire specimen letters but--what are far more useful--short
  passages, sentences, or phrases expressing the same general idea
  in various forms."--_Athenæum._

  "A careful examination has convinced us that it is unusually
  complete, well arranged, and reliable. The book is a thoroughly
  good one."--_Schoolmaster._


_=Accounts for Manufacturers.=_

  _FACTORY ACCOUNTS_: Their Principles and Practice. A Handbook
  for Accountants and Manufacturers, with Appendices on the
  Nomenclature of Machine Details; the Income Tax Acts; the Rating
  of Factories; Fire and Boiler Insurance; the Factory and Workshop
  Acts, &c., including also a Glossary of Terms and a large number
  of Specimen Rulings. By EMILE GARCKE and J. M. FELLS. Fourth
  Edition, Revised and Enlarged. Demy 8vo, 250 pages, 6_s._
  strongly bound.

  "A very interesting description of the requirements of Factory
  Accounts.... The principle of assimilating the Factory Accounts
  to the general commercial books is one which we thoroughly agree
  with."--_Accountants' Journal._

  "Characterised by extreme thoroughness. There are few owners of
  factories who would not derive great benefit from the perusal of
  this most admirable work."--_Local Government Chronicle._


_=Intuitive Calculations.=_

  _THE COMPENDIOUS CALCULATOR_; or, Easy and Concise Methods of
  Performing the various Arithmetical Operations required in
  Commercial and Business Transactions, together with Useful
  Tables. By DANIEL O'GORMAN. Corrected and Extended by Professor
  J. R. YOUNG. Twenty-seventh Edition, Revised by C. NORRIS. Fcap.
  8vo, 2_s._ 6_d._ cloth limp; or, 3_s._ 6_d._ strongly half-bound
  in leather.

  "It would be difficult to exaggerate the usefulness of a book
  like this to everyone engaged in commerce or manufacturing
  industry. It is crammed full of rules and formulæ for shortening
  and employing calculations."--_Knowledge._


_=Modern Metrical Units and Systems.=_

  _MODERN METROLOGY: A Manual of the Metrical Units and Systems
  of the Present Century._ With an Appendix containing a proposed
  English System. By LOWIS D'A. JACKSON, A.M.Inst.C.E., Author of
  "Aid to Survey Practice," &c. Large crown 8vo, 12_s._ 6_d._ cloth.

  "We recommend the work to all interested in the practical reform
  of our weights and measures."--_Nature._


_=The Metric System and the British Standards.=_

  _A SERIES OF METRIC TABLES, in which the British Standard
  Measures and Weights are compared with those of the Metric System
  at present in Use on the Continent._ By C. H. DOWLING, C.E. 8vo,
  10_s._ 6_d._ strongly bound.

  "Mr. Dowling's Tables are well put together as a ready-reckoner
  for the conversion of one system into the other."--_Athenæum._


_=Iron and Metal Trades' Calculator.=_

  _THE IRON AND METAL TRADES' COMPANION._ For expeditiously
  ascertaining the Value of any Goods bought or sold by Weight,
  from 1_s._ per cwt. to 112_s._ per cwt., and from one farthing
  per pound to one shilling per pound. By THOMAS DOWNIE. 396 pp.,
  9_s._ leather.

  "A most useful set of tables; nothing like them before
  existed."--_Building News._

  "Although specially adapted to the iron and metal trades, the
  tables will be found useful in every other business in which
  merchandise is bought and sold by weight."--_Railway News._


_=Chadwick's Calculator for Numbers and Weights Combined.=_

  _THE NUMBER, WEIGHT, AND FRACTIONAL CALCULATOR._ Containing
  upwards of 250,000 Separate Calculations, showing at a glance the
  value at 422 different rates, ranging from 1/125th of a Penny
  to 20_s._ each, or per cwt., and £20 per ton, of any number of
  articles consecutively, from 1 to 470.--Any number of cwts.,
  qrs., and lbs., from 1 cwt. to 470 cwts.--Any number of tons,
  cwts., qrs., and lbs., from 1 to 1,000 tons. By WILLIAM CHADWICK,
  Public Accountant. Third Edition, Revised and Improved. 8vo,
  18_s._, strongly bound for Office wear and tear.

==> _Is adapted for the use of Accountants and Auditors, Railway
Companies, Canal Companies, Shippers, Shipping Agents, General
Carriers, etc. Ironfounders, Brassfounders, Metal Merchants,
Iron Manufacturers, Ironmongers, Engineers, Machinists, Boiler
Makers. Millwrights, Roofing, Bridge and Girder Makers, Colliery
Proprietors, etc. Timber Merchants, Builders, Contractors,
Architects, Surveyors, Auctioneers, Valuers, Brokers, Mill Owners
and Manufacturers, Mill Furnishers, Merchants, and General
Wholesale Tradesmen. Also for the Apportionment of Mileage Charges
for Railway Traffic._

*** OPINIONS OF THE PRESS.

  "It is as easy of reference for any answer or any number of
  answers as a dictionary, and the references are even more
  quickly made. For making up accounts or estimates the book must
  prove invaluable to all who have any considerable quantity of
  calculations involving price and measure in any combination to
  do."--_Engineer._

  "The most complete and practical ready reckoner which it has been
  our fortune yet to see. It is difficult to imagine a trade or
  occupation in which it could not be of the greatest use, either
  in saving human labour or in checking work. The publishers have
  placed within the reach of every commercial man an invaluable and
  unfailing assistant."--_The Miller._

  "The most perfect work of the kind yet prepared."--_Glasgow
  Herald._


_=Harben's Comprehensive Weight Calculator.=_

  _THE WEIGHT CALCULATOR._ Being a Series of Tables upon a New
  and Comprehensive Plan, exhibiting at One Reference the exact
  Value of any Weight from 1 lb. to 15 tons, at 300 Progressive
  Rates, from 1_d._ to 168_s._ per cwt., and containing 186,000
  Direct Answers, which, with their Combinations, consisting of a
  single addition (mostly to be performed at sight), will afford
  an aggregate of 10,266,000 Answers; the whole being calculated
  and designed to ensure correctness and promote despatch. By HENRY
  HARBEN, Accountant. Fourth Edition, carefully Corrected. Royal
  8vo, £1 5_s._ strongly half-bound.

  "A practical and useful work of reference for men of
  business generally; it is the best of the kind we have
  seen."--_Ironmonger._

  "Of priceless value to business men. It is a necessary book in
  all mercantile offices."--_Sheffield Independent._


_=Harben's Comprehensive Discount Guide.=_

  _THE DISCOUNT GUIDE._ Comprising several Series of Tables for
  the use of Merchants, Manufacturers, Ironmongers, and others, by
  which may be ascertained the exact Profit arising from any mode
  of using Discounts, either in the Purchase or Sale of Goods, and
  the method of either Altering a Rate of Discount or Advancing
  a Price, so as to produce, by one operation, a sum that will
  realise any required profit after allowing one or more Discounts:
  to which are added Tables of Profit or Advance from 1¼ to 90 per
  cent., Tables of Discount from 1¼ to 98¾ per cent., and Tables
  of Commission, &c., from ⅛ to 10 per cent. By HENRY HARBEN,
  Accountant, Author of "The Weight Calculator." New Edition,
  carefully Revised and Corrected. Demy 8vo, 544 pp., £1 5_s._
  half-bound.

  "A book such as this can only be appreciated by business men to
  whom the saving of time means saving of money. We have the high
  authority of Professor J. R. Young that the tables throughout
  the work are constructed upon strictly accurate principles.
  The work is a model of typographical clearness, and must
  prove of great value to merchants, manufacturers, and general
  traders."--_British Trade Journal._


_=Iron Shipbuilders' and Merchants' Weight Tables.=_

  _IRON-PLATE WEIGHT TABLES: For Iron Shipbuilders, Engineers, and
  Iron Merchants._ Containing the Calculated Weights of upwards
  of 150,000 different sizes of Iron Plates, from 1 foot by 6 in.
  by ¼ in. to 10 feet by 5 feet by 1 in. Worked out on the basis
  of 40 lbs. to the square foot of Iron of 1 inch in thickness.
  Carefully compiled and thoroughly Revised by H. BURLINSON and W.
  H. SIMPSON. Oblong 4to, 25_s._ half-bound.

  "This work will be found of great utility. The authors have had
  much practical experience of what is wanting in making estimates:
  and the use of the book will save much time in making elaborate
  calculations."--_English Mechanic._


AGRICULTURE, FARMING, GARDENING, etc.


_Dr. Fream's New Edition of "The Standard Treatise on Agriculture."_

  _THE COMPLETE GRAZIER, and FARMER'S and CATTLE-BREEDER'S
  ASSISTANT_: A Compendium of Husbandry. Originally Written
  by WILLIAM YOUATT. Thirteenth Edition, entirely Re-written,
  considerably Enlarged, and brought up to the Present Requirements
  of Agricultural Practice, by WILLIAM FREAM, LL.D., Steven
  Lecturer in the University of Edinburgh, Author of "The Elements
  of Agriculture," &c. Royal 8vo, 1,100 pp., with over 450
  Illustrations. £1 11_s._ 6_d._ strongly and handsomely bound.

EXTRACT FROM PUBLISHERS' ADVERTISEMENT.

  "A treatise that made its original appearance in the first
  decade of the century, and that enters upon its Thirteenth
  Edition before the century has run its course, has undoubtedly
  established its position as a work of permanent value.... The
  phenomenal progress of the last dozen years in the Practice and
  Science of Farming has rendered it necessary, however, that
  the volume should be re-written, ... and for this undertaking
  the publishers were fortunate enough to secure the services of
  Dr. FREAM, whose high attainments in all matters pertaining to
  agriculture have been so emphatically recognised by the highest
  professional and official authorities. In carrying out his
  editorial duties, Dr. FREAM has been favoured with valuable
  contributions by Prof. J. WORTLEY AXE, Mr. E. BROWN, Dr. BERNARD
  DYER, Mr. W. J. MALDEN, Mr. R. H. REW, Prof. SHELDON, Mr. J.
  SINCLAIR, Mr. SANDERS SPENCER, and others.

  "As regards the illustrations of the work, no pains have been
  spared to make them as representative and characteristic as
  possible, so as to be practically useful to the Farmer and
  Grazier."

SUMMARY OF CONTENTS.

  BOOK I.    ON THE VARIETIES, BREEDING, REARING, FATTENING, AND
               MANAGEMENT OF CATTLE.
  BOOK II.   ON THE ECONOMY AND MANAGEMENT OF THE DAIRY.
  BOOK III.  ON THE BREEDING, REARING, AND MANAGEMENT OF HORSES.
  BOOK IV.   ON THE BREEDING, REARING, AND FATTENING OF SHEEP.
  BOOK V.    ON THE BREEDING, REARING, AND FATTENING OF SWINE.
  BOOK VI.   ON THE DISEASES OF LIVE STOCK.
  BOOK VII.  ON THE BREEDING, REARING, AND MANAGEMENT OF POULTRY.
  BOOK VIII. ON FARM OFFICES AND IMPLEMENTS OF HUSBANDRY.
  BOOK IX.   ON THE CULTURE AND MANAGEMENT OF GRASS LANDS.
  BOOK X.    ON THE CULTIVATION AND APPLICATION OF GRASSES, PULSE,
               AND ROOTS.
  BOOK XI.   ON MANURES AND THEIR APPLICATION TO GRASS LAND&CROPS.
  BOOK XII.  MONTHLY CALENDARS OF FARMWORK.

*** OPINIONS OF THE PRESS ON THE NEW EDITION.

  "Dr. Fream is to be congratulated on the successful attempt he
  has made to give us a work which will at once become the standard
  classic of the farm practice of the country. We believe that it
  will be found that it has no compeer among the many works at
  present in existence.... The illustrations are admirable, while
  the frontispiece, which represents the well-known bull, New
  Year's Gift, bred by the Queen, is a work of art."--_The Times._

  "The book must be recognised as occupying the proud position of
  the most exhaustive work of reference in the English language on
  the subject with which it deals."--_Athenæum._

  "The most comprehensive guide to modern farm practice that exists
  in the English language to-day.... The book is one that ought to
  be on every farm and in the library of every landowner."--_Mark
  Lane Express._

  "In point of exhaustiveness and accuracy the work will certainly
  hold a pre-eminent and unique position among books dealing with
  scientific agricultural practice. It is, in fact, an agricultural
  library of itself."--_North British Agriculturist._

  "A compendium of authoratative and well-ordered knowledge
  on every conceivable branch of the work of the live stock
  farmer; probably without an equal in this or any other
  country."--_Yorkshire Post._

  "The best and brightest guide to the practice of husbandry,
  one that has no superior--no equal we might truly say--among
  the agricultural literature now before the public.... In every
  section in which we have tested it, the work has been found
  thoroughly up to date."--_Bell's Weekly Messenger._


_=British Farm Live Stock.=_

  _FARM LIVE STOCK OF GREAT BRITAIN._ By ROBERT WALLACE, F.L.S.,
  F.R.S.E., &c., Professor of Agriculture and Rural Economy in the
  University of Edinburgh. Third Edition, thoroughly Revised and
  considerably Enlarged. With over 120 Phototypes of Prize Stock.
  Demy 8vo, 384 pp., with 79 Plates and Maps, 12_s._ 6_d._ cloth.

  "A really complete work on the history, breeds, and management
  of the farm stock of Great Britain, and one which is likely
  to find its way to the shelves of every country gentleman's
  library."--_The Times._

  "The latest edition of 'Farm Live Stock of Great Britain' is
  a production to be proud of, and its issue not the least of
  the services which its author has rendered to agricultural
  science."--_Scottish Farmer._

  "The book is very attractive ... and we can scarcely imagine the
  existence of a farmer who would not like to have a copy of this
  beautiful work."--_Mark Lane Express._

  "A work which will long be regarded as a standard authority
  whenever a concise history and description of the breeds of
  live stock in the British Isles is required."--_Bell's Weekly
  Messenger._


_=Dairy Farming.=_

  _BRITISH DAIRYING._ A Handy Volume on the Work of the Dairy-Farm.
  For the Use of Technical Instruction Classes, Students in
  Agricultural Colleges, and the Working Dairy-Farmer. By Prof. J.
  P. SHELDON, late Special Commissioner of the Canadian Government,
  Author of "Dairy Farming," &c. With numerous Illustrations. Crown
  8vo, 2_s._ 6_d._ cloth.

  "May be confidently recommended as a useful text-book on dairy
  farming.--_Agricultural Gazette._

  "Probably the best half-crown manual on dairy work that has yet
  been produced.--_North British Agriculturist._

  "It is the soundest little work we have yet seen on the
  subject."--_The Times._


_=Dairy Manual.=_

  _MILK, CHEESE AND BUTTER_: Their Composition, Character and the
  Processes of their Production. A Practical Manual for Students
  and Dairy Farmers. By JOHN OLIVER, late Principal of the Western
  Dairy Institute, Berkeley. Crown 8vo, 380 pages, with Coloured
  Test Sheets and numerous Illustrations, 7_s._ 6_d._ cloth.

  [_Just published._


_=Agricultural Facts and Figures.=_

  _NOTE-BOOK OF AGRICULTURAL FACTS AND FIGURES FOR FARMERS AND FARM
  STUDENTS._ By PRIMROSE MCCONNELL, B.Sc. Fifth Edition. Royal
  32mo, roan, gilt edges, with band, 4_s._

  "Literally teems with information, and we can cordially
  recommend it to all connected with agriculture."--_North British
  Agriculturist._


_=Small Farming.=_

  _SYSTEMATIC SMALL FARMING; or, The Lessons of my Farm._ Being an
  Introduction to Modern Farm Practice for Small Farmers. By ROBERT
  SCOTT BURN, Author of "Outlines of Modern Farming," &c. With
  numerous Illustrations, crown 8vo, 6_s._ cloth.

  "This is the completest book of its class we have seen, and one
  which every amateur farmer will read with pleasure and accept as
  a guide."--_Field._


_=Modern Farming.=_

  _OUTLINES OF MODERN FARMING._ By R. SCOTT BURN. Soils, Manures,
  and Crops--Farming and Farming Economy--Cattle, Sheep, and
  Horses--Management of Dairy, Pigs, and Poultry--Utilisation of
  Town-Sewage, Irrigation, &c. Sixth Edition. In One Vol., 1,250
  pp., half-bound, profusely Illustrated, 12_s._

  "The aim of the author has been to make his work at once
  comprehensive and trustworthy, and he has succeeded to a degree
  which entitles him to much credit."--_Morning Advertiser._


_=Agricultural Engineering.=_

  _FARM ENGINEERING, THE COMPLETE TEXT-BOOK OF._ Comprising
  Draining and Embanking; Irrigation and Water Supply; Farm Roads,
  Fences, and Gates; Farm Buildings; Barn Implements and Machines;
  Field Implements and Machines; Agricultural Surveying, &c. By
  Prof. JOHN SCOTT, In One Vol., 1,150 pages, half-bound, with over
  600 Illustrations, 12_s._

  "Written with great care, as well as with knowledge and ability.
  The author has done his work well; we have found him a very
  trustworthy guide wherever we have tested his statements. The
  volume will be of great value to agricultural students."--_Mark
  Lane Express._


_=Agricultural Text-Book.=_

  _THE FIELDS OF GREAT BRITAIN_: A Text-Book of Agriculture,
  adapted to the Syllabus of the Science and Art Department. For
  Elementary and Advanced Students. By HUGH CLEMENTS (Board of
  Trade). Second Edition, Revised, with Additions. 18mo, 2_s._
  6_d._ cloth.

  "A most comprehensive volume, giving a mass of
  information."--_Agricultural Economist._

  "It is a long time since we have seen a book which has pleased
  us more, or which contains such a vast and useful fund of
  knowledge."--_Educational Times._


_=Tables for Farmers, etc.=_

  _TABLES, MEMORANDA, AND CALCULATED RESULTS for Farmers, Graziers,
  Agricultural Students, Surveyors, Land Agents, Auctioneers, etc._
  With a New System of Farm Book-keeping. Selected and Arranged by
  SIDNEY FRANCIS. Third Edition, Revised. 272 pp., waistcoat-pocket
  size, 1_s._ 6_d._ limp leather.

  "Weighing less than 1 oz., and occupying no more space than a
  match box, it contains a mass of facts and calculations which
  has never before, in such handy form, been obtainable. Every
  operation on the farm is dealt with. The work may be taken as
  thoroughly accurate, the whole of the tables having been revised
  by Dr. Fream. We cordially recommend it."--_Bell's Weekly
  Messenger._


_=The Management of Bees.=_

  _BEES FOR PLEASURE AND PROFIT_: A Guide to the Manipulation of
  Bees, the Production of Honey, and the General Management of the
  Apiary. By G. GORDON SAMSON. With numerous Illustrations. Crown
  8vo, 1_s._ cloth.

  "The intending bee-keeper will find exactly the kind of
  information required to enable him to make a successful start
  with his hives. The author is a thoroughly competent teacher, and
  his book may be commended."--_Morning Post._


_=Farm and Estate Book-keeping.=_

  _BOOK-KEEPING FOR FARMERS & ESTATE OWNERS._ A Practical Treatise,
  presenting, in Three Plans, a System adapted for all Classes
  of Farms. By JOHNSON M. WOODMAN, Chartered Accountant. Second
  Edition, Revised. Crown 8vo, 3_s._ 6_d._ cloth boards; or 2_s._
  6_d._ cloth limp.

  "The volume is a capital study of a most important
  subject."--_Agricultural Gazette._

  "The young farmer, land agent, and surveyor will find
  Mr. Woodman's treatise more than repay its cost and
  study."--_Building News._


_=Farm Account Book.=_

  _WOODMAN'S YEARLY FARM ACCOUNT BOOK._ Giving a Weekly Labour
  Account and Diary, and showing the Income and Expenditure under
  each Department of Crops, Live Stock, Dairy, &c. &c. With
  Valuation, Profit and Loss Account, and Balance Sheet at the end
  of the Year. By JOHNSON M. WOODMAN, Chartered Accountant, Author
  of "Book-keeping for Farmers." Folio, 7_s._ 6_d._ half-bound.

  "Contains every requisite form for keeping farm accounts readily
  and accurately."--_Agriculture._


_=Early Fruits, Flowers, and Vegetables.=_

  _THE FORCING GARDEN_; or, How to Grow Early Fruits, Flowers, and
  Vegetables. With Plans and Estimates for Building Glasshouses,
  Pits, and Frames. With Illustrations. By SAMUEL WOOD. Crown 8vo,
  3_s._ 6_d._ cloth.

  "A good book, and fairly fills a place that was in some degree
  vacant. The book is written with great care, and contains a great
  deal of valuable teaching."--_Gardeners' Magazine._


_=Good Gardening.=_

  _A PLAIN GUIDE TO GOOD GARDENING_; or, How to Grow Vegetables,
  Fruits, and Flowers. By S. WOOD. Fourth Edition, with
  considerable Additions, &c., and numerous Illustrations. Crown
  8vo, 3_s._ 6_d._ cl.

  "A very good book, and one to be highly recommended
  as a practical guide. The practical directions are
  excellent."--_Athenæum._

  "May be recommended to young gardeners, cottagers, and specially
  to amateurs, for the plain, simple, and trustworthy information
  it gives on common matters too often neglected."--_Gardeners'
  Chronicle._


_=Gainful Gardening.=_

  _MULTUM-IN-PARVO GARDENING_; or, How to make One Acre of Land
  produce £620 a-year by the Cultivation of Fruits and Vegetables;
  also, How to Grow Flowers in Three Glass Houses, so as to
  realise £176 per annum clear Profit. By SAMUEL WOOD, Author of
  "Good Gardening," &c. Fifth and Cheaper Edition, Revised, with
  Additions. Crown 8vo, 1_s._ sewed.

  "We are bound to recommend it as not only suited to the case
  of the amateur and gentleman's gardener, but to the market
  grower."--_Gardeners' Magazine._


_=Gardening for Ladies.=_

  _THE LADIES' MULTUM-IN-PARVO FLOWER GARDEN, and Amateurs'
  Complete Guide._ With Illusts. By S. WOOD. Cr. 8vo, 3_s._ 6_d._
  cl.

  "This volume contains a good deal of sound common sense
  instruction."--_Florist._

  "Full of shrewd hints and useful instructions, based on a
  lifetime of experience."--_Scotsman._


_=Receipts for Gardeners.=_

  _GARDEN RECEIPTS._ Edited by CHARLES W. QUIN. 12mo, 1_s._ 6_d._
  cloth limp.

  "A useful and handy book, containing a good deal of valuable
  information."--_Athenæum._


_=Market Gardening.=_

  _MARKET AND KITCHEN GARDENING._ By Contributors to "The Garden."
  Compiled by C. W. SHAW, late Editor of "Gardening Illustrated."
  12mo, 3_s._ 6_d._ cloth boards.

  "The most valuable compendium of kitchen and market-garden work
  published."--_Farmer._


_=Cottage Gardening.=_

  _COTTAGE GARDENING; or, Flowers, Fruits, and Vegetables for Small
  Gardens._ By E. HOBDAY. 12mo, 1_s._ 6_d._ cloth limp.

  "Contains much useful information at a small charge."--_Glasgow
  Herald._


AUCTIONEERING, VALUING, LAND SURVEYING ESTATE AGENCY, etc.


_=Auctioneer's Assistant.=_

  _THE APPRAISER, AUCTIONEER, BROKER, HOUSE AND ESTATE AGENT AND
  VALUER'S POCKET ASSISTANT_, for the Valuation for Purchase, Sale,
  or Renewal of Leases, Annuities and Reversions, and of property
  generally; with Prices for Inventories, &c. By JOHN WHEELER,
  Valuer, &c. Sixth Edition, Re-written and greatly extended by C.
  NORRIS, Surveyor, Valuer, &c. Royal 32mo, 5_s._ cloth.

  "A neat and concise book of reference, containing an admirable
  and clearly-arranged list of prices for inventories, and a
  very practical guide to determine the value of furniture,
  &c."--_Standard._

  "Contains a large quantity of varied and useful information
  as to the valuation for purchase, sale, or renewal of leases,
  annuities and reversions, and of property generally, with prices
  for inventories, and a guide to determine the value of interior
  fittings and other effects."--_Builder._


_=Auctioneering.=_

  _AUCTIONEERS: THEIR DUTIES AND LIABILITIES._ A Manual of
  Instruction and Counsel for the Young Auctioneer. By ROBERT
  SQUIBBS, Auctioneer. Second Edition, Revised and partly
  Re-written. Demy 8vo, 12_s._ 6_d._ cloth.

*** OPINIONS OF THE PRESS.

  "The standard text-book on the topics of which it
  treats."--_Athenæum._

  "The work is one of general excellent character, and gives much
  information in a compendious and satisfactory form."--_Builder._

  "May be recommended as giving a great deal of information on the
  law relating to auctioneers, in a very readable form."--_Law
  Journal._

  "Auctioneers may be congratulated on having so pleasing a writer
  to minister to their special needs."--_Solicitors' Journal._

  "Every auctioneer ought to possess a copy of this excellent
  work."--_Ironmonger._

  "Of great value to the profession.... We readily welcome this
  book from the fact that it treats the subject in a manner
  somewhat new to the profession."--_Estates Gazette._


_=Inwood's Estate Tables.=_

  _TABLES FOR THE PURCHASING OF ESTATES, Freehold, Copyhold, or
  Leasehold; Annuities, Advowsons, etc._, and for the Renewing
  of Leases held under Cathedral Churches, Colleges, or other
  Corporate bodies, for Terms of Years certain, and for Lives:
  also for Valuing Reversionary Estates, Deferred Annuities, Next
  Presentations, &c.; together with SMART'S Five Tables of Compound
  Interest, and an Extension of the same to Lower and Intermediate
  Rates. By W. INWOOD. 24th Edition, with considerable Additions,
  and new and valuable Tables of Logarithms for the more Difficult
  Computations of the Interest of Money, Discount, Annuities, &c.,
  by M. FEDOR THOMAN, of the Société Crédit Mobilier of Paris.
  Crown 8vo, 8_s._ cloth.

  "Those interested in the purchase and sale of estates, and in the
  adjustment of compensation cases, as well as in transactions in
  annuities, life insurances, &c., will find the present edition of
  eminent service."--_Engineering._

  "'Inwood's Tables' still maintain a most enviable reputation. The
  new issue has been enriched by large additional contributions by
  M. Fedor Thoman, whose carefully arranged Tables cannot fail to
  be of the utmost utility."--_Mining Journal._


_=Agricultural Valuer's Assistant.=_

  _THE AGRICULTURAL VALUER'S ASSISTANT._ A Practical Handbook
  on the Valuation of Landed Estates; including Rules and
  Data for Measuring and Estimating the Contents, Weights,
  and Values of Agricultural Produce and Timber, and the
  Values of Feeding Stuffs, Manures, and Labour; with Forms of
  Tenant-Right-Valuations, Lists of Local Agricultural Customs,
  Scales of Compensation under the Agricultural Holdings Act, &c.
  &c. By TOM BRIGHT, Agricultural Surveyor. Second Edition, much
  Enlarged. Crown 8vo, 5_s._ cloth.

  "Full of tables and examples in connection with the valuation of
  tenant-right, estates, labour, contents, and weights of timber,
  and farm produce of all kinds."--_Agricultural Gazette._

  "An eminently practical handbook, full of practical tables and
  data of undoubted interest and value to surveyors and auctioneers
  in preparing valuations of all kinds."--_Farmer._


_=Plantations and Underwoods.=_

  _POLE PLANTATIONS AND UNDERWOODS_: A Practical Handbook on
  Estimating the Cost of Forming, Renovating, Improving, and
  Grubbing Plantations and Underwoods, their Valuation for Purposes
  of Transfer, Rental, Sale, or Assessment. By TOM BRIGHT, Author
  of "The Agricultural Valuer's Assistant," &c. Crown 8vo, 3_s._
  6_d._ cloth.

  "To valuers, foresters and agents it will be a welcome
  aid."--_North British Agriculturist._

  "Well calculated to assist the valuer in the discharge of his
  duties, and of undoubted interest and use both to surveyors and
  auctioneers in preparing valuations of all kinds."--_Kent Herald._


_=Hudson's Land Valuer's Pocket-Book.=_

  _THE LAND VALUER'S BEST ASSISTANT_: Being Tables on a very much
  Improved Plan, for Calculating the Value of Estates. With Tables
  for reducing Scotch, Irish, and Provincial Customary Acres to
  Statute Measure, &c. By R. HUDSON, C.E. New Edition. Royal 32mo,
  leather, elastic band, 4_s._

  "Of incalculable value to the country gentleman and professional
  man."--_Farmers' Journal._


_=Ewart's Land Improver's Pocket-Book.=_

  _THE LAND IMPROVER'S POCKET-BOOK OF FORMULÆ, TABLES, and
  MEMORANDA required in any Computation relating to the Permanent
  Improvement of Landed Property._ By JOHN EWART, Land Surveyor
  and Agricultural Engineer. Second Edition, Revised. Royal 32mo,
  oblong, leather, gilt edges, with elastic band, 4_s._

  "A compendious and handy little volume."--_Spectator._


_=Complete Agricultural Surveyor's Pocket-Book.=_

  _THE LAND VALUER'S AND LAND IMPROVER'S COMPLETE POCKET-BOOK._
  Being of the above Two Works bound together. Leather, with strap,
  7_s._ 6_d._


_=House Property.=_

  _HANDBOOK OF HOUSE PROPERTY._ A Popular and Practical Guide to
  the Purchase, Mortgage, Tenancy, and Compulsory Sale of Houses
  and Land, including the Law of Dilapidations and Fixtures;
  with Examples of all kinds of Valuations, Useful Information
  on Building, and Suggestive Elucidations of Fine Art. By E. L.
  TARBUCK, Architect and Surveyor. Fifth Edition, Enlarged. 12mo,
  5_s._ cloth.

  "The advice is thoroughly practical."--_Law Journal._

  "For all who have dealings with house property, this is an
  indispensable guide."--_Decoration._

  "Carefully brought up to date, and much improved by the addition
  of a division on fine art.... A well-written and thoughtful
  work."--_Land Agent's Record._


LAW AND MISCELLANEOUS.


_=Private Bill Legislation and Provisional Orders.=_

  _HANDBOOK FOR THE USE OF SOLICITORS AND ENGINEERS_ Engaged in
  Promoting Private Acts of Parliament and Provisional Orders, for
  the Authorization of Railways, Tramways, Works for the Supply of
  Gas and Water, and other undertakings of a like character. By
  L. LIVINGSTON MACASSEY, of the Middle Temple, Barrister-at-Law,
  M.Inst.C.E.; Author of "Hints on Water Supply." Demy 8vo, 950
  pp., 25_s._ cl.

  "The author's double experience as an engineer and barrister has
  enabled him to approach the subject alike from an engineering and
  legal point of view."--_Local Government Chronicle._


_=Law of Patents.=_

  _PATENTS FOR INVENTIONS, AND HOW TO PROCURE THEM._ Compiled
  for the Use of Inventors, Patentees and others. By G. G. M.
  HARDINGHAM, Assoc.Mem.Inst.C.E., &c. Demy 8vo, 1_s._ 6_d._ cloth.


_=Labour Disputes.=_

  _INDUSTRIAL CONCILIATION AND ARBITRATION_: An Historical Sketch,
  with Practical Suggestions for the Settlement of Labour Disputes.
  By J. S. JEANS, Author of "Railway Problems," "England's
  Supremacy," &c. Crown 8vo, 200 pp., 2_s._ 6_d._ cloth.

  [_Just published._


_=Pocket-Book for Sanitary Officials.=_

  _THE HEALTH OFFICER'S POCKET-BOOK_: A Guide to Sanitary Practice
  and Law. For Medical Officers of Health, Sanitary Inspectors,
  Members of Sanitary Authorities, &c. By EDWARD F. WILLOUGHBY,
  M.D. (Lond.), &c., Author of "Hygiene and Public Health." Fcap.
  8vo, 7_s._ 6_d._ cloth, red edges, rounded corners.

  [_Just published._

  "A mine of condensed information of a pertinent and useful
  kind on the various subjects of which it treats. The matter
  seems to have been carefully compiled and arranged for facility
  of reference, and it is well illustrated by diagrams and
  woodcuts. The different subjects are succinctly but fully and
  scientifically dealt with."--_The Lancet._

  "Ought to be welcome to those for whose use it is designed,
  since it practically boils down a reference library into
  a pocket volume.... It combines, with an uncommon degree
  of efficiency, the qualities of accuracy, conciseness and
  comprehensiveness."--_Scotsman._

  "An excellent publication, dealing with the scientific, technical
  and legal matters connected with the duties of medical officers
  of health and sanitary inspectors. The work is replete with
  information."--_Local Government Journal._


_=A Complete Epitome of the Laws of this Country.=_

  _EVERY MAN'S OWN LAWYER: A Handy-Book of the Principles of Law
  and Equity._ By A BARRISTER. Thirty-first Edition, carefully
  Revised, and including the Legislation of 1893. Comprising
  (amongst other Acts) the _Voluntary Conveyances Act_, 1893; the
  _Married Women's Property Act_, 1893; the _Trustee Act_, 1893;
  the _Savings Bank Act_, 1893; the _Barbed Wire Act_, 1893; the
  _Industrial and Provident Societies Act_, 1893; the _Hours of
  Labour of Railway Servants Act_, 1893; the _Fertiliser and
  Feeding Stuffs Act_, 1893, &c., as well as the _Betting and Loans
  (Infants) Act_, 1892; the _Gaming Act_, 1892; the _Shop Hours
  Act_, 1892; the _Conveyancing and Real Property Act_, 1892;
  the _Small Holdings Act_, 1892; and many other new Acts. Crown
  8vo, 700 pp., price 6_s._ 8_d._ (saved at every consultation!),
  strongly bound in cloth.

  [_Just published._

*** _The Book will be found to comprise (amongst other matter)_--

THE RIGHTS AND WRONGS OF INDIVIDUALS--LANDLORD AND
TENANT--VENDORS AND PURCHASERS--PARTNERS AND AGENTS--COMPANIES
AND ASSOCIATIONS--MASTERS, SERVANTS, AND WORKMEN--LEASES AND
MORTGAGES--LIBEL AND SLANDER--CONTRACTS AND AGREEMENTS--BONDS
AND BILLS OF SALE--CHEQUES, BILLS, AND NOTES--RAILWAY AND
SHIPPING LAW--BANKRUPTCY AND INSURANCE--BORROWERS, LENDERS,
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*** The volumes of this Series are freely Illustrated with
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CIVIL ENGINEERING, SURVEYING, ETC.

  No.

  31. _WELLS AND WELL-SINKING._ By JOHN GEO. SWINDELL, A.R.I.B.A.,
  and G. R. BURNELL, C.E. Revised Edition. With a New Appendix on
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  35. _THE BLASTING AND QUARRYING OF STONE_, for Building and other
  Purposes. By Gen. Sir J. BURGOYNE, Bart. 1s. 6d.

  43. _TUBULAR, AND OTHER IRON GIRDER BRIDGES_, particularly
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  44. _FOUNDATIONS AND CONCRETE WORKS_, with Practical Remarks on
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  60. _LAND AND ENGINEERING SURVEYING._ By T. BAKER, C.E. Fifteenth
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  80*. _EMBANKING LANDS FROM THE SEA._ With examples and
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  81. _WATER WORKS_, for the Supply of Cities and Towns. With a
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  118. _CIVIL ENGINEERING IN NORTH AMERICA_, a Sketch of. By DAVID
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  167. _IRON BRIDGES, GIRDERS, ROOFS, AND OTHER WORKS._ By FRANCIS
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  197. _ROADS AND STREETS._ By H. LAW, C.E., revised and enlarged
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  203. _SANITARY WORK IN THE SMALLER TOWNS AND IN VILLAGES._ By C.
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  212. _GAS-WORKS, THEIR CONSTRUCTION AND ARRANGEMENT_; and the
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  216. _MATERIALS AND CONSTRUCTION_; A Theoretical and Practical
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  219. _CIVIL ENGINEERING._ By HENRY LAW, M.Inst. C.E. Including
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  268. _THE DRAINAGE OF LANDS, TOWNS, & BUILDINGS._ By G. D.
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MECHANICAL ENGINEERING, ETC.

  33. _CRANES_, the Construction of, and other Machinery for
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  34. _THE STEAM ENGINE._ By Dr. LARDNER. Illustrated. 1s. 6d.

  59. _STEAM BOILERS_: their Construction and Management. By R.
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  82. _THE POWER OF WATER_, as applied to drive Flour Mills, and to
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  98. _PRACTICAL MECHANISM_, the Elements of; and Machine Tools. By
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  139. _THE STEAM ENGINE_, a Treatise on the Mathematical Theory
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  164. _MODERN WORKSHOP PRACTICE_, as applied to Steam Engines,
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  165. _IRON AND HEAT_, exhibiting the Principles concerned in the
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  166. _POWER IN MOTION_: Horse-Power, Toothed-Wheel Gearing, Long
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  190. _STEAM AND THE STEAM ENGINE_, Stationary and Portable. By J.
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  200. _FUEL_, its Combustion and Economy. By C. W. WILLIAMS. With
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MINING, METALLURGY, ETC.

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  176. _METALLURGY OF IRON._ Containing History of Iron
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  Processes of Manufacture of Iron and Steel, &c. By H. BAUERMAN,
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  180. _COAL AND COAL MINING._ By the late Sir WARINGTON W. SMYTH,
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  195. _THE MINERAL SURVEYOR AND VALUER'S COMPLETE GUIDE._ By W.
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  214. _SLATE AND SLATE QUARRYING_, Scientific, Practical, and
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  264. _A FIRST BOOK OF MINING AND QUARRYING_, with the Sciences
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ARCHITECTURE, BUILDING, ETC.

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*** ORDERS AND STYLES OF ARCHITECTURE, _in One Vol., 3s. 6d._

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*** _The three preceding Works, in One handsome Vol., half-bound,
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  45. _LIMES, CEMENTS, MORTARS, CONCRETES, MASTICS, PLASTERING_,
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  127. _ARCHITECTURAL MODELLING IN PAPER_, the Art of. By T. A.
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  128. _VITRUVIUS--THE ARCHITECTURE OF MARCUS VITRUVIUS POLLO._ In
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  130. _GRECIAN ARCHITECTURE_, An Inquiry into the Principles of
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*** _The two preceding Works in One handsome Vol., half bound,
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  132. _THE ERECTION OF DWELLING-HOUSES._ Illustrated by a
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  Estimates, &c. By S. H. BROOKS. New Edition, with Plates. 2s. 6d.‡

  156. _QUANTITIES & MEASUREMENTS_ in Bricklayers', Masons',
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  175. _LOCKWOOD'S BUILDER'S PRICE BOOK FOR 1893._ A Comprehensive
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  3s. 6d.; cloth boards, 4s.

  [_Just Published._

  182. _CARPENTRY AND JOINERY_--THE ELEMENTARY PRINCIPLES OF
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  182*. _CARPENTRY AND JOINERY. ATLAS_ of 35 Plates to accompany
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  185. _THE COMPLETE MEASURER_; the Measurement of Boards, Glass,
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  187. _HINTS TO YOUNG ARCHITECTS._ By G. WIGHTWICK. New Edition.
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  188. _HOUSE PAINTING, GRAINING, MARBLING, AND SIGN WRITING_: with
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  189. _THE RUDIMENTS OF PRACTICAL BRICKLAYING._ In Six Sections:
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  Paving, Tiling, Materials; Slating and Plastering; Practical
  Geometry, Mensuration, &c. By ADAM HAMMOND. Seventh Edition. 1s.
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  191. _PLUMBING._ A Text-Book to the Practice of the Art or
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  192. _THE TIMBER IMPORTER'S, TIMBER MERCHANT'S, and BUILDER'S
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  206. _A BOOK ON BUILDING, Civil and Ecclesiastical_, including
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  226. _THE JOINTS MADE AND USED BY BUILDERS_ in the Construction
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  228. _THE CONSTRUCTION OF ROOFS OF WOOD AND IRON._ By E. WYNDHAM
  TARN, M.A., Architect. Second Edition, revised. 1s. 6d.

  229. _ELEMENTARY DECORATION_: as applied to the Interior and
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  257. _PRACTICAL HOUSE DECORATION._ A Guide to the Art of
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*** _The two preceding Works, in One handsome Vol., half-bound,
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  230. _A PRACTICAL TREATISE ON HANDRAILING._ Showing New and
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  247. _BUILDING ESTATES_: a Rudimentary Treatise on the
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  248. _PORTLAND CEMENT FOR USERS._ By HENRY FAIJA, Assoc. M. Inst.
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  252. _BRICKWORK_: a Practical Treatise, embodying the General and
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  253. _THE TIMBER MERCHANT'S, SAW-MILLER'S, AND IMPORTER'S
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  258. _CIRCULAR WORK IN CARPENTRY AND JOINERY._ A Practical
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  259. _GAS FITTING_: A Practical Handbook treating of every
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  261. _SHORING AND ITS APPLICATION_: A Handbook for the Use of
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  [_Just published._

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ENGLISH LANGUAGE AND MISCELLANEOUS.

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LONDON: CROSBY LOCKWOOD AND SON,
7, STATIONERS' HALL COURT, LUDGATE HILL, E.C.



      *      *      *      *      *      *



Transcriber's note:

  Obvious typographical errors and punctuation errors have been
  corrected after careful comparison with other occurrences within
  the text and consultation of external sources.

  Two unpaired double quotation marks could not be corrected.

  Except for those changes noted below, all misspellings in the text,
  and inconsistent or archaic usage, have been retained. For example,
  Brazil wood, Brazil-wood; paper mills, paper-mills; india-rubber,
  indiarubber; inodorous; pectous; decoction; silicious; inclosed.

  Pg 34, in the first row of the table, to save space
         '70 per cent.' replaced by '70%'.
  Pg 80, 'Process for reating' replaced by 'Process for Treating'.
  Pg 208, 'the chimey-shaft' replaced by 'the chimney-shaft'.
  Pg 208, 'cylinders urrounding' replaced by 'cylinder surrounding'.
  Pg 229, 'may done rapidly' replaced by 'may be done rapidly'.
  Footnote 34, 'intsrument maker' replaced by 'instrument maker'.

  Publisher's Book Catalogs:

  Obvious typographical errors and punctuation errors have been
  corrected. Other minor errors and misspellings have been left
  unchanged.

  Sometimes only the first line of a book title was italicized in the
  original text; the full title has been italicized in this etext.

  The footer on each page of the second Catalog has been removed,
  except for the final page which has both the even- and odd-page
  footer.





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