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Title: Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 3 - "Destructors" to "Diameter"
Author: Various
Language: English
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Transcriber's note: A few typographical errors have been corrected: they
  are listed at the end of the text. Due to space constraints, italics
  denoting underscores were not used in the tables.


                          THE ENCYCLOPÆDIA BRITANNICA

      A DICTIONARY OF ARTS, SCIENCES, LITERATURE AND GENERAL INFORMATION

                              ELEVENTH EDITION

                           VOLUME VIII slice III

                           Destructor to Diameter



DESTRUCTOR (_continued from volume 8, slice 2, page 0108._)
  ... in main flues, &c. (g) The chimney draught must be assisted with
  forced draught from fans or steam jet to a pressure of 1½ in. to 2 in.
  under grates by water-gauge. (h) Where a destructor is required to
  work without risk of nuisance to the neighbouring inhabitants, its
  efficiency as a refuse destructor plant must be primarily kept in view
  in designing the works, steam-raising being regarded as a secondary
  consideration. Boilers should not be placed immediately over a furnace
  so as to present a large cooling surface, whereby the temperature of
  the gases is reduced before the organic matter has been thoroughly
  burned. (i) Where steam-power and a high fuel efficiency are desired a
  large percentage of CO_{2} should be sought in the furnaces with as
  little excess of air as possible, and the flue gases should be
  utilized in heating the air-supply to the grates, and the feed-water
  to the boilers. (j) Ample boiler capacity and hot-water storage
  feed-tanks should be included in the design where steam-power is
  required.

  [Sidenote: Cost.]

  As to the initial cost of the erection of refuse destructors, few
  trustworthy data can be given. The outlay necessarily depends, amongst
  other things, upon the difficulty of preparing the site, upon the
  nature of the foundations required, the height of the chimney-shaft,
  the length of the inclined or approach roadway, and the varying prices
  of labour and materials in different localities. As an example may be
  mentioned the case of Bristol, where, in 1892, the total cost of
  constructing a 16-cell Fryer destructor was £11,418, of which £2909
  was expended on foundations, and £1689 on the chimney-shaft; the cost
  of the destructor proper, buildings and approach road was therefore
  £6820, or about £426 per cell. The cost per ton of burning refuse in
  destructors depends mainly upon--(a) The price of labour in the
  locality, and the number of "shifts" or changes of workmen per day;
  (b) the type of furnace adopted; (c) the nature of the material to be
  consumed; (d) the interest on and repayment of capital outlay. The
  cost of burning ton for ton consumed, in high-temperature furnaces,
  including labour and repairs, is not greater than in slow-combustion
  destructors. The average cost of burning refuse at twenty-four
  different towns throughout England, exclusive of interest on the cost
  of the works, is 1s. 1½d. per ton burned; the minimum cost is 6d. per
  ton at Bradford, and the maximum cost 2s. 10d. per ton at Battersea.
  At Shoreditch the cost per ton for the year ending on the 25th of
  March 1899, including labour, supervision, stores, repairs, &c. (but
  exclusive of interest on cost of works), was 2s. 6.9d. The quantity of
  refuse burned per cell per day of 24 hours varies from about 4 tons up
  to 20 tons. The ordinary low-temperature destructor, with 25 sq. ft.
  grate area, burns about 20 lb. of refuse per square foot of grate
  area per hour, or between 5 and 6 tons per cell per 24 hours. The
  Meldrum destructor furnaces at Rochdale burn as much as 66 lb. per
  square foot of grate area per hour, and the Beaman and Deas destructor
  at Llandudno 71.7 lb. per square foot per hour. The amount, however,
  always depends materially on the care observed in stoking, the nature
  of the material, the frequency of removal of clinker, and on the
  question whether the whole of the refuse passed into the furnace is
  thoroughly cremated.

  [Sidenote: Residues:]

  The amount of residue in the shape of clinker and fine ash varies from
  22 to 37% of the bulk dealt with. From 25 to 30% is a very usual
  amount. At Shoreditch, where the refuse consists of about 8% of straw,
  paper, shavings, &c., the residue contains about 29% clinker, 2.7%
  fine ash, .5% flue dust, and .6% old tins, making a total residue of
  32.8%. As the residuum amounts to from one-fourth to one-third of the
  total bulk of the refuse dealt with, it is a question of the utmost
  importance that some profitable, or at least inexpensive, means should
  be devised for its regular disposal. Among other purposes, it has been
  used for bottoming for macadamized roads, for the manufacture of
  concrete, for making paving slabs, for forming suburban footpaths or
  cinder footwalks, and for the manufacture of mortar. The last is a
  very general, and in many places profitable, mode of disposal. An
  entirely new outlet has also arisen for the disposal of good
  well-vitrified destructor clinker in connexion with the construction
  of bacteria beds for sewage disposal, and in many districts its value
  has, by this means, become greatly enhanced.

  [Sidenote: Forced draught.]

  Through defects in the design and management of many of the early
  destructors complaints of nuisance frequently arose, and these have,
  to some extent, brought destructor installations into disrepute.
  Although some of the older furnaces were decided offenders in this
  respect, that is by no means the case with the modern improved type of
  high-temperature furnace; and often, were it not for the great
  prominence in the landscape of a tall chimney-shaft, the existence of
  a refuse destructor in a neighbourhood would not be generally known to
  the inhabitants. A modern furnace, properly designed and worked, will
  give rise to no nuisance, and may be safely erected in the midst of a
  populous neighbourhood. To ensure the perfect cremation of the refuse
  and of the gases given off, forced draught is essential. This is
  supplied either as air draught delivered from a rapidly revolving fan,
  or as steam blast, as in the Horsfall steam jet or the Meldrum blower.
  With a forced blast less air is required to obtain complete combustion
  than by chimney draught. The forced draught grate requires little more
  than the quantity theoretically necessary, while with chimney draught
  more than double the theoretical amount of air must be supplied. With
  forced draught, too, a much higher temperature is attained, and if it
  is properly worked, little or no cold air will enter the furnaces
  during stoking operations. As far as possible a balance of pressure in
  the cells during clinkering should be maintained just sufficient to
  prevent an inrush of cold air through the flues. The forced draught
  pressure should not exceed 2 in. water-gauge. The efficiency of the
  combustion in the furnace is conveniently measured by the
  "Econometer," which registers continuously and automatically the
  proportion of CO_{2} passing away in the waste gases; the higher the
  percentage of CO_{2} the more efficient the furnace, provided there is
  no formation of CO, the presence of which would indicate incomplete
  combustion. The theoretical maximum of CO_{2} for refuse burning is
  about 20%; and, by maintaining an even clean fire, by admitting
  secondary air over the fire, and by regulating the dampers or the
  air-pressure in the ash-pit, an amount approximating to this
  percentage may be attained in a well-designed furnace if properly
  worked. If the proportion of free oxygen (i.e. excess of air) is
  large, more air is passed through the furnace than is required for
  complete combustion, and the heating of this excess is clearly a waste
  of heat. The position of the econometer in testing should be as near
  the furnace as possible, as there may be considerable air leakage
  through the brickwork of the flues.

  The air supply to modern furnaces is usually delivered hot, the inlet
  air being first passed through an air-heater the temperature of which
  is maintained by the waste gases in the main flue.

  [Sidenote: Calorific value.]

  The modern high-temperature destructor, to render the refuse and gases
  perfectly innocuous and harmless, is worked at a temperature varying
  from 1250° to 2000° F., and the maintenance of such temperatures has
  very naturally suggested the possibility of utilizing this heat-energy
  for the production of steam-power. Experience shows that a
  considerable amount of energy may be derived from steam-raising
  destructor stations, amply justifying a reasonable increase of
  expenditure on plant and labour. The actual calorific value of the
  refuse material necessarily varies, but, as a general average, with
  suitably designed and properly managed plant, an evaporation of 1 lb.
  of water per pound of refuse burned is a result which may be readily
  attained, and affords a basis of calculation which engineers may
  safely adopt in practice. Many destructor steam-raising plants,
  however, give considerably higher results, evaporations approaching 2
  lb. of water per pound of refuse being often met with under
  favourable conditions.

  From actual experience it may be accepted, therefore, that the
  calorific value of unscreened house refuse varies from 1 to 2 lb. of
  water evaporated per pound of refuse burned, the exact proportion
  depending upon the quality and condition of the material dealt with.
  Taking the evaporative power of coal at 10 lb. of water per pound of
  coal, this gives for domestic house refuse a value of from {1/10} to
  {1/5} that of coal; or, with coal at 20s. per ton, refuse has a
  commercial value of from 2s. to 4s. per ton. In London the quantity of
  house refuse amounts to about 1¼ million tons per annum, which is
  equivalent to from 4 cwt. to 5 cwt. per head per annum. If it be
  burned in furnaces giving an evaporation of 1 lb. of water per pound
  of refuse, it would yield a total power annually of about 138 million
  brake horse-power hours, and equivalent cost of coal at 20s. per ton
  for this amount of power even when calculated upon the very low
  estimate of 2 lb.[1] of coal per brake horse-power hour, works out at
  over £123,000. On the same basis, the refuse of a medium-sized town,
  with, say, a population of 70,000 yielding refuse at the rate of 5
  cwt. per head per annum, would afford 112 indicated horse-power per
  ton burned, and the total indicated horse-power hours per annum would
  be

       70,000 × 5 cwt.
       --------------- × 112 = 1,960,000 I.H.P. hours annually.
              20

  If this were applied to the production of electric energy, the
  electrical horse-power hours would be (with a dynamo efficiency of
  90%)

       1,960,000 × 90
       -------------- = 1,764,000 E.H.P. hours per annum;
            100

  and the watt-hours per annum at the central station would be

                 1,764,000 × 746 = 1,315,944,000.

  Allowing for a loss of 10% in distribution, this would give
  1,184,349,600 watt-hours available in lamps, or with 8-candle-power
  lamps taking 30 watts of current per lamp, we should have

   1,184,349,600 watt-hours
   ------------------------ = 39,478,320 8-c.p. lamp-hours per annum;
           30 watts

               39,478,320
  that is, ----------------- = 563 8-c.p. lamp hours per annum per
           70,000 population           head of population.

  Taking the loss due to the storage which would be necessary at 20% on
  three-quarters of the total or 15% upon the whole, there would be 478
  8-c.p. lamp-hours per annum per head of the population: i.e. if the
  power developed from the refuse were fully utilized, it would supply
  electric light at the rate of one 8-c.p. lamp per head of the
  population for about 1{1/3} hours for every night of the year.

  [Sidenote: Difficulties.]

  In actual practice, when the electric energy is for the purposes of
  lighting only, difficulty has been experienced in fully utilizing the
  thermal energy from a destructor plant owing to the want of adequate
  means of storage either of the thermal or of the electric energy. A
  destructor station usually yields a fairly definite amount of thermal
  energy uniformly throughout the 24 hours, while the consumption of
  electric-lighting current is extremely irregular, the maximum demand
  being about four times the mean demand. The period during which the
  demand exceeds the mean is comparatively short, and does not exceed
  about 6 hours out of the 24, while for a portion of the time the
  demand may not exceed {1/20}th of the maximum. This difficulty, at
  first regarded as somewhat grave, is substantially minimized by the
  provision of ample boiler capacity, or by the introduction of feed
  thermal storage vessels in which hot feed-water may be stored during
  the hours of light load (say 18 out of the 24), so that at the time of
  maximum load the boiler may be filled directly from these vessels,
  which work at the same pressure and temperature as the boiler.
  Further, the difficulty above mentioned will disappear entirely at
  stations where there is a fair day load which practically ceases at
  about the hour when the illuminating load comes on, thus equalizing
  the demand upon both destructor and electric plant throughout the 24
  hours. This arises in cases where current is consumed during the day
  for motors, fans, lifts, electric tramways, and other like purposes,
  and, as the employment of electric energy for these services is
  rapidly becoming general, no difficulty need be anticipated in the
  successful working of combined destructor and electric plants where
  these conditions prevail. The more uniform the electrical demand
  becomes, the more fully may the power from a destructor station be
  utilized.

  In addition to combination with electric-lighting works, refuse
  destructors are now very commonly installed in conjunction with
  various other classes of power-using undertakings, including tramways,
  water-works, sewage-pumping, artificial slab-making and
  clinker-crushing works and others; and the increasingly large sums
  which are being yearly expended in combined undertakings of this
  character is perhaps the strongest evidence of the practical value of
  such combinations where these several classes of work must be carried
  on.

  For further information on the subject, reference should be made to
  William H. Maxwell, _Removal and Disposal of Town Refuse, with an
  exhaustive treatment of Refuse Destructor Plants_ (London, 1899), with
  a special _Supplement_ embodying later results (London, 1905).

  See also the _Proceedings of the Incorporated Association of Municipal
  and County Engineers_, vols. xiii. p. 216, xxii. p. 211, xxiv. p. 214
  and xxv. p. 138; also the _Proceedings of the Institution of Civil
  Engineers_, vols. cxxii. p. 443, cxxiv. p. 469, cxxxi. p. 413,
  cxxxviii. p. 508, cxxix. p. 434, cxxx. pp. 213 and 347, cxxiii. pp.
  369 and 498, cxxviii. p. 293 and cxxxv. p. 300.           (W. H. MA.)

[1] With medium-sized steam plants, a consumption of 4 lb. of coal per
brake horse-power per hour is a very usual performance.


DE TABLEY, JOHN BYRNE LEICESTER WARREN, 3rd BARON (1835-1895), English
poet, eldest son of George Fleming Leicester (afterwards Warren), 2nd
Baron De Tabley, was born on the 26th of April 1835. He was educated at
Eton and Christ Church, Oxford, where he took his degree in 1856 with
second classes in classics and in law and modern history. In the autumn
of 1858 he went to Turkey as unpaid attaché to Lord Stratford de
Redcliffe, and two years later was called to the bar. He became an
officer in the Cheshire Yeomanry, and unsuccessfully contested
Mid-Cheshire in 1868 as a Liberal. After his father's second marriage in
1871 he removed to London, where he became a close friend of Tennyson
for several years. From 1877 till his succession to the title in 1887 he
was lost to his friends, assuming the life of a recluse. It was not till
1892 that he returned to London life, and enjoyed a sort of renaissance
of reputation and friendship. During the later years of his life Lord De
Tabley made many new friends, besides reopening old associations, and he
almost seemed to be gathering around him a small literary company when
his health broke, and he died on the 22nd of November 1895 at Ryde, in
his sixty-first year. He was buried at Little Peover in Cheshire.
Although his reputation will live almost exclusively as that of a poet,
De Tabley was a man of many studious tastes. He was at one time an
authority on numismatics; he wrote two novels; published _A Guide to the
Study of Book Plates_ (1880); and the fruit of his careful researches in
botany was printed posthumously in his elaborate _Flora of Cheshire_
(1899). Poetry, however, was his first and last passion, and to that he
devoted the best energies of his life. De Tabley's first impulse towards
poetry came from his friend George Fortescue, with whom he shared a
close companionship during his Oxford days, and whom he lost, as
Tennyson lost Hallam, within a few years of their taking their degrees.
Fortescue was killed by falling from the mast of Lord Drogheda's yacht
in November 1859, and this gloomy event plunged De Tabley into deep
depression. Between 1859 and 1862 De Tabley issued four little volumes
of pseudonymous verse (by G. F. Preston), in the production of which he
had been greatly stimulated by the sympathy of Fortescue. Once more he
assumed a pseudonym--his _Praeterita_ (1863) bearing the name of William
Lancaster. In the next year he published _Eclogues and Monodramas_,
followed in 1865 by _Studies in Verse_. These volumes all displayed
technical grace and much natural beauty; but it was not till the
publication of _Philoctetes_ in 1866 that De Tabley met with any wide
recognition. _Philoctetes_ bore the initials "M.A.," which, to the
author's dismay, were interpreted as meaning Matthew Arnold. He at once
disclosed his identity, and received the congratulations of his friends,
among whom were Tennyson, Browning and Gladstone. In 1867 he published
_Orestes_, in 1870 _Rehearsals_ and in 1873 _Searching the Net_. These
last two bore his own name, John Leicester Warren. He was somewhat
disappointed by their lukewarm reception, and when in 1876 _The Soldier
of Fortune_, a drama on which he had bestowed much careful labour,
proved a complete failure, he retired altogether from the literary
arena. It was not until 1893 that he was persuaded to return, and the
immediate success in that year of his _Poems, Dramatic and Lyrical_,
encouraged him to publish a second series in 1895, the year of his
death. The genuine interest with which these volumes were welcomed did
much to lighten the last years of a somewhat sombre and solitary life.
His posthumous poems were collected in 1902. The characteristics of De
Tabley's poetry are pre-eminently magnificence of style, derived from
close study of Milton, sonority, dignity, weight and colour. His passion
for detail was both a strength and a weakness: it lent a loving fidelity
to his description of natural objects, but it sometimes involved him in
a loss of simple effect from over-elaboration of treatment. He was
always a student of the classic poets, and drew much of his inspiration
directly from them. He was a true and a whole-hearted artist, who, as a
brother poet well said, "still climbed the clear cold altitudes of
song." His ambition was always for the heights, a region naturally
ice-bound at periods, but always a country of clear atmosphere and
bright, vivid outlines.

  See an excellent sketch by E. Gosse in his _Critical Kit-Kats_ (1896).
                                                                (A. WA.)


DETAILLE, JEAN BAPTISTE ÉDOUARD (1848- ), French painter, was born in
Paris on the 5th of October 1848. After working as a pupil of
Meissonier's, he first exhibited, in the Salon of 1867, a picture
representing "A Corner of Meissonier's Studio." Military life was from
the first a principal attraction to the young painter, and he gained his
reputation by depicting the scenes of a soldier's life with every detail
truthfully rendered. He exhibited "A Halt" (1868); "Soldiers at rest,
during the Manoeuvres at the Camp of Saint Maur" (1869); "Engagement
between Cossacks and the Imperial Guard, 1814" (1870). The war of
1870-71 furnished him with a series of subjects which gained him
repeated successes. Among his more important pictures may be named "The
Conquerors" (1872); "The Retreat" (1873); "The Charge of the 9th
Regiment of Cuirassiers in the Village of Morsbronn, 6th August 1870"
(1874); "The Marching Regiment, Paris, December 1874" (1875); "A
Reconnaissance" (1876); "Hail to the Wounded!" (1877); "Bonaparte in
Egypt" (1878); the "Inauguration of the New Opera House"--a
water-colour; the "Defence of Champigny by Faron's Division" (1879). He
also worked with Alphonse de Neuville on the panorama of Rezonville. In
1884 he exhibited at the Salon the "Evening at Rezonville," a panoramic
study, and "The Dream" (1888), now in the Luxemburg. Detaille recorded
other events in the military history of his country: the "Sortie of the
Garrison of Huningue" (now in the Luxemburg), the "Vincendon Brigade,"
and "Bizerte," reminiscences of the expedition to Tunis. After a visit
to Russia, Detaille exhibited "The Cossacks of the Ataman" and "The
Hereditary Grand Duke at the Head of the Hussars of the Guard." Other
important works are: "Victims to Duty," "The Prince of Wales and the
Duke of Connaught" and "Pasteur's Funeral." In his picture of "Châlons,
9th October 1896," exhibited in the Salon, 1898, Detaille painted the
emperor and empress of Russia at a review, with M. Félix Faure. Detaille
became a member of the French Institute in 1898.

   See Marius Vachon, _Detaille_ (Paris, 1898); Frédéric Masson,
  _Édouard Detaille and his work_ (Paris and London, 1891); J. Claretie,
  _Peintres et sculpteurs contemporains_ (Paris, 1876); G. Goetschy,
  _Les Jeunes peintres militaires_ (Paris, 1878).


DETAINER (from _detain_, Lat. _detinere_), in law, the act of keeping a
person against his will, or the wrongful keeping of a person's goods, or
other real or personal property. A writ of detainer was a form for the
beginning of a personal action against a person already lodged within
the walls of a prison; it was superseded by the Judgment Act 1838.


DETERMINANT, in mathematics, a function which presents itself in the
solution of a system of simple equations.

1. Considering the equations

                   ax  + by  + cz  = d,
                   a'x + b'y + c'z = d',
                   a"x + b"y + c"z = d",

and proceeding to solve them by the so-called method of cross
multiplication, we multiply the equations by factors selected in such a
manner that upon adding the results the whole coefficient of y becomes =
0, and the whole coefficient of z becomes = 0; the factors in question
are b'c" - b"c', b"c - bc", bc' - b'c (values which, as at once seen,
have the desired property); we thus obtain an equation which contains on
the left-hand side only a multiple of x, and on the right-hand side a
constant term; the coefficient of x has the value

          a(b'c" - b"c') + a'(b"c - bc") + a"(bc' - b'c),

and this function, represented in the form

                         |a,  b,  c |,
                         |a', b', c'|
                         |a", b", c"|

is said to be a determinant; or, the number of elements being 3², it is
called a determinant of the third order. It is to be noticed that the
resulting equation is

                |a,  b,  c | x = |d,  b,  c |
                |a', b', c'|     |d', b', c'|
                |a", b", c"|     |d", b", c"|

where the expression on the right-hand side is the like function with d,
d', d" in place of a, a', a" respectively, and is of course also a
determinant. Moreover, the functions b'c" - b"c', b"c - bc", bc' - b'c
used in the process are themselves the determinants of the second order

                |b', c'|, |b", c"|, |b,  c |.
                |b", c"|  |b,  c |  |b', c'|

We have herein the suggestion of the rule for the derivation of the
determinants of the orders 1, 2, 3, 4, &c., each from the preceding one,
viz. we have

  |a|      = a,

  |a,  b | = a|b'| - a'|b|.
  |a', b'|

  |a,  b,  c | = a|b', c'| + a'|b", c"| + a"|b,  c |,
  |a', b', c'|    |b", c"|     |b , c |     |b', c'|
  |a", b", c"|

  |a,   b  , c  , d  | = a|b',  c',  d' | - a'|b" , c" , d" | +
  |a',  b' , c' , d' |    |b",  c",  d" |     |b"', c"', d"'|
  |a",  b" , c" , d" |    |b"', c"', d"'|     |b  , c  , d  |
  |a"', b"', c"', d"'|

                      + a"|b"', c"', d"'| - a"'|b , c,  d |,
                          |b  , c  , d  |      |b', c', d'|
                          |b' , c' , d' |      |b", c", d"|

and so on, the terms being all + for a determinant of an odd order, but
alternately + and - for a determinant of an even order.

2. It is easy, by induction, to arrive at the general results:--

A determinant of the order n is the sum of the 1.2.3...n products which
can be formed with n elements out of n² elements arranged in the form of
a square, no two of the n elements being in the same line or in the same
column, and each such product having the coefficient ± unity.

The products in question may be obtained by permuting in every possible
manner the columns (or the lines) of the determinant, and then taking
for the factors the n elements in the dexter diagonal. And we thence
derive the rule for the signs, viz. considering the primitive
arrangement of the columns as positive, then an arrangement obtained
therefrom by a single interchange (inversion, or derangement) of two
columns is regarded as negative; and so in general an arrangement is
positive or negative according as it is derived from the primitive
arrangement by an even or an odd number of interchanges. [This implies
the theorem that a given arrangement can be derived from the primitive
arrangement only by an odd number, or else only by an even number of
interchanges,--a theorem the verification of which may be easily
obtained from the theorem (in fact a particular case of the general
one), an arrangement can be derived from itself only by an even number
of interchanges.] And this being so, each product has the sign belonging
to the corresponding arrangement of the columns; in particular, a
determinant contains with the sign + the product of the elements in its
dexter diagonal. It is to be observed that the rule gives as many
positive as negative arrangements, the number of each being = ½ 1.2...n.

The rule of signs may be expressed in a different form. Giving to the
columns in the primitive arrangement the numbers 1, 2, 3 ... n, to
obtain the sign belonging to any other arrangement we take, as often as
a lower number succeeds a higher one, the sign -, and, compounding
together all these minus signs, obtain the proper sign, + or - as the
case may be.

Thus, for three columns, it appears by either rule that 123, 231, 312
are positive; 213, 321, 132 are negative; and the developed expression
of the foregoing determinant of the third order is

           = ab'c" - ab"c' + a'b"c - a'bc" + a"bc' - a"b'c.

3. It further appears that a determinant is a linear function[1] of the
elements of each column thereof, and also a linear function of the
elements of each line thereof; moreover, that the determinant retains
the same value, only its sign being altered, when any two columns are
interchanged, or when any two lines are interchanged; more generally,
when the columns are permuted in any manner, or when the lines are
permuted in any manner, the determinant retains its original value, with
the sign + or - according as the new arrangement (considered as derived
from the primitive arrangement) is positive or negative according to the
foregoing rule of signs. It at once follows that, if two columns are
identical, or if two lines are identical, the value of the determinant
is = 0. It may be added, that if the lines are converted into columns,
and the columns into lines, in such a way as to leave the dexter
diagonal unaltered, the value of the determinant is unaltered; the
determinant is in this case said to be _transposed_.

4. By what precedes it appears that there exists a function of the n²
elements, linear as regards the terms of each column (or say, for
shortness, linear as to each column), and such that only the sign is
altered when any two columns are interchanged; these properties
completely determine the function, except as to a common factor which
may multiply all the terms. If, to get rid of this arbitrary common
factor, we assume that the product of the elements in the dexter
diagonal has the coefficient +1, we have a complete definition of the
determinant, and it is interesting to show how from these properties,
assumed for the definition of the determinant, it at once appears that
the determinant is a function serving for the solution of a system of
linear equations. Observe that the properties show at once that if any
column is = 0 (that is, if the elements in the column are each = 0),
then the determinant is = 0; and further, that if any two columns are
identical, then the determinant is = 0.

5. Reverting to the system of linear equations written down at the
beginning of this article, consider the determinant

                 |ax  + by  + cz  - d , b , c |;
                 |a'x + b'y + c'z - d', b', c'|
                 |a"x + b"y + c"z - d", b", c"|

it appears that this is

  = x|a , b , c | + y|b , b , c | + z|c , b , c | - |d , b , c |;
     |a', b', c'|    |b', b', c'|    |c', b', c'|   |d', b', c'|
     |a", b", c"|    |b", b", c"|    |c", b", c"|   |d", b", c"|

viz. the second and third terms each vanishing, it is

                = x|a , b , c | - |d , b , c |.
                   |a', b', c'|   |d', b', c'|
                   |a", b", c"|   |d", b", c"|

But if the linear equations hold good, then the first column of the
original determinant is = 0, and therefore the determinant itself is = 0;
that is, the linear equations give

                x|a , b , c | - |d , b , c | = 0;
                 |a', b', c'|   |d', b', c'|
                 |a", b", c"|   |d", b", c"|

which is the result obtained above.

We might in a similar way find the values of y and z, but there is a
more symmetrical process. Join to the original equations the new
equation

            [alpha]x + [beta]y + [gamma]z = [delta];

a like process shows that, the equations being satisfied, we have

           |[alpha], [beta], [gamma], [delta]| = 0;
           |   a   ,    b  ,    c   , d      |
           |   a'  ,    b' ,    c'  , d'     |
           |   a"  ,    b" ,    c"  , d"     |

or, as this may be written,

     |[alpha], [beta], [gamma]    | - [delta]| a , b , c | = 0:
     |   a   ,   b   ,    c   , d |          | a', b', c'|
     |   a'  ,   b'  ,    c'  , d'|          | a", b", c"|
     |   a"  ,   b"  ,    c"  , d"|          |           |

which, considering [delta] as standing herein for its value [alpha]x +
[beta]y + [gamma]z, is a consequence of the original equations only: we
have thus an expression for [alpha]x + [beta]y + [gamma]z, an arbitrary
linear function of the unknown quantities x, y, z; and by comparing the
coefficients of [alpha], [beta], [gamma] on the two sides respectively,
we have the values of x, y, z; in fact, these quantities, each
multiplied by

                      |a , b , c |,
                      |a', b', c'|
                      |a", b", c"|

are in the first instance obtained in the forms

       |1             |, |    1         |, |        1     |;
       |a , b , c , d |  |a , b , c , d |  |a , b , c , d |
       |a', b', c', d'|  |a', b', c', d'|  |a', b', c', d'|
       |a", b", c", d"|  |a", b", c", d"|  |a", b", c", d"|

but these are

         = |b , c , d |, - |c , d , a |, |d , a , b |,
           |b', c', d'|    |c', d', a'|  |d', a', b'|
           |b", c", d"|    |c", d", a"|  |d", a", b"|

or, what is the same thing,

         = |b , c , d |, |c , a , d |, |a , b , d |
           |b', c', d'|  |c', a', d'|  |a', b', d'|
           |b", c", d"|  |c", a", d"|  |a", b", d"|

respectively.

6. _Multiplication of two Determinants of the same Order._--The theorem
is obtained very easily from the last preceding definition of a
determinant. It is most simply expressed thus--

              ([alpha], [alpha]', [alpha]"),
                     ([beta],[beta]',[beta]"),
                           ([gamma],[gamma]',[gamma]")
              +---------------------------------------+
  (a , b , c )|          "       "       "            | =
  (a', b', c')|          "       "       "            |
  (a", b", c")|          "       "       "            |

                        = |a , b , c |. |[alpha] , [beta] , [gamma] |,
                          |a', b', c'|  |[alpha]', [beta]', [gamma]'|
                          |a", b", c"|  |[alpha]", [beta]", [gamma]"|

where the expression on the left side stands for a determinant, the
terms of the first line being (a, b, c)([alpha], [alpha]', [alpha]"),
that is, a[alpha] + b[alpha]' + c[alpha]", (a, b, c)([beta], [beta]',
[beta]"), that is, a[beta] + b[beta]' + c[beta]", (a, b, c)([gamma],
[gamma]', [gamma]"), that is a[gamma] + b[gamma]' + c[gamma]"; and
similarly the terms in the second and third lines are the life functions
with (a', b', c') and (a", b", c") respectively.

There is an apparently arbitrary transposition of lines and columns; the
result would hold good if on the left-hand side we had written ([alpha],
[beta], [gamma]), ([alpha]', [beta]', [gamma]'), ([alpha]", [beta]",
[gamma]"), or what is the same thing, if on the right-hand side we had
transposed the second determinant; and either of these changes would, it
might be thought, increase the elegance of the form, but, for a reason
which need not be explained,[2] the form actually adopted is the
preferable one.

To indicate the method of proof, observe that the determinant on the
left-hand side, _qua_ linear function of its columns, may be broken up
into a sum of (3³ =) 27 determinants, each of which is either of some
such form as

         = [alpha][beta][gamma]'|a , a , b |,
                                |a', a', b'|
                                |a", a", b"|


where the term [alpha][beta][gamma]' is not a term of the
[alpha][beta][gamma]-determinant, and its coefficient (as a determinant
with two identical columns) vanishes; or else it is of a form such as

         = [alpha][beta]'[gamma]"|a , b , c |,
                                 |a', b', c'|
                                 |a", b", c"|

that is, every term which does not vanish contains as a factor the
abc-determinant last written down; the sum of all other factors ±
[alpha][beta]'[gamma]" is the [alpha][beta][gamma]-determinant of the
formula; and the final result then is, that the determinant on the
left-hand side is equal to the product on the right-hand side of the
formula.

7. _Decomposition of a Determinant into complementary
Determinants._--Consider, for simplicity, a determinant of the fifth
order, 5 = 2 + 3, and let the top two lines be

                        a , b , c , d , e
                        a', b', c', d', e'

then, if we consider how these elements enter into the determinant, it
is at once seen that they enter only through the determinants of the
second order |a , b |, &c., which can be formed by selecting any two
             |a', b'|
columns at pleasure. Moreover, representing the remaining three lines by

                   a" , b" , c" , d" , e"
                   a"', b"', c"', d"', e"'
                   a"", b"", c"", d"", e""

it is further seen that the factor which multiplies the determinant
formed with any two columns of the first set is the determinant of the
third order formed with the complementary three columns of the second
set; and it thus appears that the determinant of the fifth order is a
sum of all the products of the form

                 = |a , b |  |c" , d" , e" |,
                   |a', b"|  |c"', d"', e"'|
                             |c"", d"", e""|

the sign ± being in each case such that the sign of the term ±
ab'c"d'"e"" obtained from the diagonal elements of the component
determinants may be the actual sign of this term in the determinant of
the fifth order; for the product written down the sign is obviously +.

Observe that for a determinant of the n-th order, taking the
decomposition to be 1 + (n - 1), we fall back upon the equations given
at the commencement, in order to show the genesis of a determinant.

8. Any determinant |a , b | formed out of the elements of the original
                   |a', b'|
determinant, by selecting the lines and columns at pleasure, is termed a
_minor_ of the original determinant; and when the number of lines and
columns, or order of the determinant, is n-1, then such determinant is
called a _first minor_; the number of the first minors is = n², the
first minors, in fact, corresponding to the several elements of the
determinant--that is, the coefficient therein of any term whatever is
the corresponding first minor. The first minors, each divided by the
determinant itself, form a system of elements _inverse_ to the elements
of the determinant.

A determinant is _symmetrical_ when every two elements symmetrically
situated in regard to the dexter diagonal are equal to each other; if
they are equal and opposite (that is, if the sum of the two elements be
= 0), this relation not extending to the diagonal elements themselves,
which remain arbitrary, then the determinant is _skew_; but if the
relation does extend to the diagonal terms (that is, if these are each =
0), then the determinant is _skew symmetrical_; thus the determinants

  |a, h, g|; |    a ,     [nu],  - [mu]|; |     0,      [nu],  - [mu]|
  |h, b, f|  |- [nu],        b,[lambda]|  |- [nu],         0,[lambda]|
  |g, f, c|  |  [mu],-[lambda],      c |  |  [mu],- [lambda],       0|

are respectively symmetrical, skew and skew symmetrical:

The theory admits of very extensive algebraic developments, and
applications in algebraical geometry and other parts of mathematics. For
further developments of the theory of determinants see ALGEBRAIC FORMS.
                                                                (A. CA.)

  9. _History._--These functions were originally known as "resultants,"
  a name applied to them by Pierre Simon Laplace, but now replaced by
  the title "determinants," a name first applied to certain forms of
  them by Carl Friedrich Gauss. The germ of the theory of determinants
  is to be found in the writings of Gottfried Wilhelm Leibnitz (1693),
  who incidentally discovered certain properties when reducing the
  eliminant of a system of linear equations. Gabriel Cramer, in a note
  to his _Analyse des lignes courbes algébriques_ (1750), gave the rule
  which establishes the sign of a product as _plus_ or _minus_ according
  as the number of displacements from the typical form has been even or
  odd. Determinants were also employed by Étienne Bezout in 1764, but
  the first connected account of these functions was published in 1772
  by Charles Auguste Vandermonde. Laplace developed a theorem of
  Vandermonde for the expansion of a determinant, and in 1773 Joseph
  Louis Lagrange, in his memoir on _Pyramids_, used determinants of the
  third order, and proved that the square of a determinant was also a
  determinant. Although he obtained results now identified with
  determinants, Lagrange did not discuss these functions systematically.
  In 1801 Gauss published his _Disquisitiones arithmeticae_, which,
  although written in an obscure form, gave a new impetus to
  investigations on this and kindred subjects. To Gauss is due the
  establishment of the important theorem, that the product of two
  determinants both of the second and third orders is a determinant. The
  formulation of the general theory is due to Augustin Louis Cauchy,
  whose work was the forerunner of the brilliant discoveries made in the
  following decades by Hoëné-Wronski and J. Binet in France, Carl Gustav
  Jacobi in Germany, and James Joseph Sylvester and Arthur Cayley in
  England. Jacobi's researches were published in _Crelle's Journal_
  (1826-1841). In these papers the subject was recast and enriched by
  new and important theorems, through which the name of Jacobi is
  indissolubly associated with this branch of science. The far-reaching
  discoveries of Sylvester and Cayley rank as one of the most important
  developments of pure mathematics. Numerous new fields were opened up,
  and have been diligently explored by many mathematicians.
  Skew-determinants were studied by Cayley; axisymmetric-determinants by
  Jacobi, V. A. Lebesque, Sylvester and O. Hesse, and centro-symmetric
  determinants by W. R. F. Scott and G. Zehfuss. Continuants have been
  discussed by Sylvester; alternants by Cauchy, Jacobi, N. Trudi, H.
  Nagelbach and G. Garbieri; circulants by E. Catalan, W. Spottiswoode
  and J. W. L. Glaisher, and Wronskians by E. B. Christoffel and G.
  Frobenius. Determinants composed of binomial coefficients have been
  studied by V. von Zeipel; the expression of definite integrals as
  determinants by A. Tissot and A. Enneper, and the expression of
  continued fractions as determinants by Jacobi, V. Nachreiner, S.
  Günther and E. Fürstenau. (See T. Muir, _Theory of Determinants_,
  1906).

[1] The expression, a linear function, is here used in its narrowest
sense, a linear function without constant term; what is meant is that
the determinant is in regard to the elements a, a', a", ... of any
column or line thereof, a function of the form Aa + A'a' + A"a" + ...
without any term independent of a, a', a" ...

[2] The reason is the connexion with the corresponding theorem for the
multiplication of two matrices.


DETERMINISM (Lat. _determinare_, to prescribe or limit), in ethics, the
name given to the theory that all moral choice, so called, is the
determined or necessary result of psychological and other conditions. It
is opposed to the various doctrines of Free-Will, known as voluntarism,
libertarianism, indeterminism, and is from the ethical standpoint more
or less akin to necessitarianism and fatalism. There are various degrees
of determinism. It may be held that every action is causally connected
not only externally with the sum of the agent's environment, but also
internally with his motives and impulses. In other words, if we could
know exactly all these conditions, we should be able to forecast with
mathematical certainty the course which the agent would pursue. In this
theory the agent cannot be held responsible for his action in any sense.
It is the extreme antithesis of Indeterminism or Indifferentism, the
doctrine that a man is absolutely free to choose between alternative
courses (the _liberum arbitrium indifferentiae_). Since, however, the
evidence of ordinary consciousness almost always goes to prove that the
individual, especially in relation to future acts, regards himself as
being free within certain limitations to make his own choice of
alternatives, many determinists go so far as to admit that there may be
in any action which is neither reflex nor determined by external causes
solely an element of freedom. This view is corroborated by the
phenomenon of remorse, in which the agent feels that he ought to, and
could, have chosen a different course of action. These two kinds of
determinism are sometimes distinguished as "hard" and "soft"
determinism. The controversy between determinism and libertarianism
hinges largely on the significance of the word "motive"; indeed in no
other philosophical controversy has so much difficulty been caused by
purely verbal disputation and ambiguity of expression. How far, and in
what sense, can action which is determined by motives be said to be
free? For a long time the advocates of free-will, in their eagerness to
preserve moral responsibility, went so far as to deny all motives as
influencing moral action. Such a contention, however, clearly defeats
its own object by reducing all action to chance. On the other hand, the
scientific doctrine of evolution has gone far towards obliterating the
distinction between external and internal compulsion, e.g. motives,
character and the like. In so far as man can be shown to be the product
of, and a link in, a long chain of causal development, so far does it
become impossible to regard him as self-determined. Even in his motives
and his impulses, in his mental attitude towards outward surroundings,
in his appetites and aversions, inherited tendency and environment have
been found to play a very large part; indeed many thinkers hold that the
whole of a man's development, mental as well as physical, is determined
by external conditions.

In the Bible the philosophical-religious problem is nowhere discussed,
but Christian ethics as set forth in the New Testament assumes
throughout the freedom of the human will. It has been argued by
theologians that the doctrine of divine fore-knowledge, coupled with
that of the divine origin of all things, necessarily implies that all
human action was fore-ordained from the beginning of the world. Such an
inference is, however, clearly at variance with the whole doctrine of
sin, repentance and the atonement, as also with that of eternal reward
and punishment, which postulates a real measure of human responsibility.

For the history of the free-will controversy see the articles, WILL,
PREDESTINATION (for the theological problems), ETHICS.


DETINUE (O. Fr. _detenue_, from _detenir_, to hold back), in law, an
action whereby one who has an absolute or a special property in goods
seeks to recover from another who is in actual possession and refuses to
redeliver them. If the plaintiff succeeds in an action of detinue, the
judgment is that he recover the chattel or, if it cannot be had, its
value, which is assessed by the judge and jury, and also certain damages
for detaining the same. An order for the restitution of the specific
goods may be enforced by a special writ of execution, called a writ of
delivery. (See CONTRACT; TROVER.)


DETMOLD, a town of Germany, capital of the principality of
Lippe-Detmold, beautifully situated on the east slope of the Teutoburger
Wald, 25 m. S. of Minden, on the Herford-Altenbeken line of the Prussian
state railways. Pop. (1905) 13,164. The residential château of the
princes of Lippe-Detmold (1550), in the Renaissance style, is an
imposing building, lying with its pretty gardens nearly in the centre of
the town; whilst at the entrance to the large park on the south is the
New Palace (1708-1718), enlarged in 1850, used as the dower-house.
Detmold possesses a natural history museum, theatre, high school,
library, the house in which the poet Ferdinand Freiligrath (1810-1876)
was born, and that in which the dramatist Christian Dietrich Grabbe
(1801-1836), also a native, died. The leading industries are
linen-weaving, tanning, brewing, horse-dealing and the quarrying of
marble and gypsum. About 3 m. to the south-west of the town is the
Grotenburg, with Ernst von Bandel's colossal statue of Hermann or
Arminius, the leader of the Cherusci. Detmold (Thiatmelli) was in 783
the scene of a conflict between the Saxons and the troops of
Charlemagne.


DETROIT, the largest city of Michigan, U.S.A., and the county-seat of
Wayne county, on the Detroit river opposite Windsor, Canada, about 4 m.
W. from the outlet of Lake St Clair and 18 m. above Lake Erie. Pop.
(1880) 116,340; (1890) 205,876; (1900) 285,704, of whom 96,503 were
foreign-born and 4111 were negroes; (1910 census) 465,766. Of the
foreign-born in 1900, 32,027 were Germans and 10,703 were German Poles,
25,403 were English Canadians and 3541 French Canadians, 6347 were
English and 6412 were Irish. Detroit is served by the Michigan Central,
the Lake Shore & Michigan Southern, the Wabash, the Grand Trunk, the
Père Marquette, the Detroit & Toledo Shore Line, the Detroit, Toledo &
Ironton and the Canadian Pacific railways. Two belt lines, one 2 m. to 3
m., and the other 6 m. from the centre of the city, connect the factory
districts with the main railway lines. Trains are ferried across the
river to Windsor, and steamboats make daily trips to Cleveland,
Wyandotte, Mount Clemens, Port Huron, to less important places between,
and to several Canadian ports. Detroit is also the S. terminus for
several lines to more remote lake ports, and electric lines extend from
here to Port Huron, Flint, Pontiac, Jackson, Toledo and Grand Rapids.

The city extended in 1907 over about 41 sq. m., an increase from 29 sq.
m. in 1900 and 36 sq. m. in 1905. Its area in proportion to its
population is much greater than that of most of the larger cities of the
United States. Baltimore, for example, had in 1904 nearly 70% more
inhabitants (estimated), while its area at that time was a little less
and in 1907 was nearly one-quarter less than that of Detroit. The ground
within the city limits as well as that for several miles farther back is
quite level, but rises gradually from the river bank, which is only a
few feet in height. The Detroit river, along which the city extends for
about 10 m., is here ½ m. wide and 30 ft. to 40 ft. deep; its current is
quite rapid; its water, a beautiful clear blue; at its mouth it has a
width of about 10 m., and in the river there are a number of islands,
which during the summer are popular resorts. The city has a 3 m.
frontage on the river Rouge, an estuary of the Detroit, with a 16 ft.
channel. Before the fire by which the city was destroyed in 1805, the
streets were only 12 ft. wide and were unpaved and extremely dirty. But
when the rebuilding began, several avenues from 100 ft. to 200 ft. wide
were--through the influence of Augustus B. Woodward (c. 1775-1827), one
of the territorial judges at the time and an admirer of the plan of the
city of Washington--made to radiate from two central points. From a half
circle called the Grand Circus there radiate avenues 120 ft. and 200 ft.
wide. About ¼ m. toward the river from this was established another
focal point called the Campus Martius, 600 ft. long and 400 ft. wide, at
which commence radiating or cross streets 80 ft. and 100 ft. wide.
Running north from the river through the Campus Martius and the Grand
Circus is Woodward Avenue, 120 ft. wide, dividing the present city, as
it did the old town, into nearly equal parts. Parallel with the river is
Jefferson Avenue, also 120 ft. wide. The first of these avenues is the
principal retail street along its lower portion, and is a residence
avenue for 4 m. beyond this. Jefferson is the principal wholesale street
at the lower end, and a fine residence avenue E. of this. Many of the
other residence streets are 80 ft. wide. The setting of shade trees was
early encouraged, and large elms and maples abound. The intersections of
the diagonal streets left a number of small, triangular parks, which, as
well as the larger ones, are well shaded. The streets are paved mostly
with asphalt and brick, though cedar and stone have been much used, and
kreodone block to some extent. In few, if any, other American cities of
equal size are the streets and avenues kept so clean. The Grand
Boulevard, 150 ft. to 200 ft. in width and 12 m. in length, has been
constructed around the city except along the river front. A very large
proportion of the inhabitants of Detroit own their homes: there are no
large congested tenement-house districts; and many streets in various
parts of the city are faced with rows of low and humble cottages often
having a garden plot in front.

Of the public buildings the city hall (erected 1868-1871), overlooking
the Campus Martius, is in Renaissance style, in three storeys; the
flagstaff from the top of the tower reaches a height of 200 ft. On the
four corners above the first section of the tower are four figures, each
14 ft. in height, to represent Justice, Industry, Art and Commerce, and
on the same level with these is a clock weighing 7670 lb--one of the
largest in the world. In front of the building stands the Soldiers' and
Sailors' monument, 60 ft. high, designed by Randolph Rogers (1825-1892)
and unveiled in 1872. At each of the four corners in each of three
sections rising one above the other are bronze eagles and figures
representing the United States Infantry, Marine, Cavalry and Artillery,
also Victory, Union, Emancipation and History; the figure by which the
monument is surmounted was designed to symbolize Michigan. A larger and
more massive and stately building than the city hall is the county
court house, facing Cadillac Square, with a lofty tower surmounted by a
gilded dome. The Federal building is a massive granite structure, finely
decorated in the interior. Among the churches of greatest architectural
beauty are the First Congregational, with a fine Byzantine interior, St
John's Episcopal, the Woodward Avenue Baptist and the First
Presbyterian, all on Woodward Avenue, and St. Anne's and Sacred Heart of
Mary, both Roman Catholic. The municipal museum of art, in Jefferson
Avenue, contains some unusually interesting Egyptian and Japanese
collections, the Scripps' collection of old masters, other valuable
paintings, and a small library; free lectures on art are given here
through the winter. The public library had 228,500 volumes in 1908,
including one of the best collections of state and town histories in the
country. A large private collection, owned by C. M. Burton and relating
principally to the history of Detroit, is also open to the public. The
city is not rich in outdoor works of art. The principal ones are the
Merrill fountain and the soldiers' monument on the Campus Martius, and a
statue of Mayor Pingree in West Grand Circus Park.

The parks of Detroit are numerous and their total area is about 1200
acres. By far the most attractive is Belle Isle, an island in the river
at the E. end of the city, purchased in 1879 and having an area of more
than 700 acres. The Grand Circus Park of 4½ acres, with its trees,
flowers and fountains, affords a pleasant resting place in the busiest
quarter of the city. Six miles farther out on Woodward Avenue is Palmer
Park of about 140 acres, given to the city in 1894 and named in honour
of the donor. Clark Park (28 acres) is in the W. part of the city, and
there are various smaller parks. The principal cemeteries are Elmwood
(Protestant) and Mount Elliott (Catholic), which lie adjoining in the E.
part of the city; Woodmere in the W. and Woodlawn in the N. part of the
city.

_Charity and Education._--Among the charitable institutions are the
general hospitals (Harper, Grace and St Mary's); the Detroit Emergency,
the Children's Free and the United States Marine hospitals; St Luke's
hospital, church home, and orphanage; the House of Providence (a
maternity hospital and infant asylum); the Woman's hospital and
foundling's home; the Home for convalescent children, &c. In 1894 the
mayor, Hazen Senter Pingree (1842-1901), instituted the practice of
preparing, through municipal aid and supervision, large tracts of vacant
land in and about the city for the growing of potatoes and other
vegetables and then, in conjunction with the board of poor
commissioners, assigning it in small lots to families of the unemployed,
and furnishing them with seed for planting. This plan served an
admirable purpose through three years of industrial depression, and was
copied in other cities; it was abandoned when, with the renewal of
industrial activity, the necessity for it ceased. The leading penal
institution of the city is the Detroit House of Correction, noted for
its efficient reformatory work; the inmates are employed ten hours a
day, chiefly in making furniture. The house of correction pays the city
a profit of $35,000 to $40,000 a year. The educational institutions, in
addition to those of the general public school system, include several
parochial schools, schools of art and of music, and commercial colleges;
Detroit College (Catholic), opened in 1877; the Detroit College of
Medicine, opened in 1885; the Michigan College of Medicine and Surgery,
opened in 1888; the Detroit College of law, founded in 1891, and a city
normal school.

_Commerce._--Detroit's location gives to the city's shipping and
shipbuilding interests a high importance. All the enormous traffic
between the upper and lower lakes passes through the Detroit river. In
1907 the number of vessels recorded was 34,149, with registered tonnage
of 53,959,769, carrying 71,226,895 tons of freight, valued at
$697,311,302. This includes vessels which delivered part or all of their
cargo at Detroit. The largest item in the freights is iron ore on
vessels bound down. The next is coal on vessels up bound. Grain and
lumber are the next largest items. Detroit is a port of entry, and its
foreign commerce, chiefly with Canada, is of growing importance. The
city's exports increased from $11,325,807 in 1896 to $37,085,027 in
1909. The imports were $3,153,609 in 1896 and $7,100,659 in 1909.

As a manufacturing city, Detroit holds high rank. The total number of
manufacturing establishments in 1890 was 1746, with a product for the
year valued at $77,351,546; in 1900 there were 2847 establishments with
a product for the year valued at $100,892,838; or an increase of 30.4%
in the decade. In 1900 the establishments under the factory system,
omitting the hand trades and neighbourhood industries, numbered 1259 and
produced goods valued at $88,365,924; in 1904 establishments under the
factory system numbered 1363 and the product had increased 45.7% to
$128,761,658. In the district subsequently annexed the product in 1904
was about $12,000,000, making a total of $140,000,000. The output for
1906 was estimated at $180,000,000. The state factory inspectors in 1905
visited 1721 factories having 83,231 employees. In 1906 they inspected
1790 factories with 93,071 employees. Detroit is the leading city in the
country in the manufacture of automobiles. In 1904 the value of its
product was one-fifth that for the whole country. In 1906 the city had
twenty automobile factories, with an output of 11,000 cars, valued at
$12,000,000. Detroit is probably the largest manufacturer in the country
of freight cars, stoves, pharmaceutical preparations, varnish, soda ash
and similar alkaline products. Other important manufactures are ships,
paints, foundry and machine shop products, brass goods, furniture, boots
and shoes, clothing, matches, cigars, malt liquors and fur goods; and
slaughtering and meat packing is an important industry.

The Detroit Board of Commerce, organized in 1903, brought into one
association the members of three former bodies, making a compact
organization with civic as well as commercial aims. The board has
brought into active co-operation nearly all the leading business men of
the city and many of the professional men. Their united efforts have
brought many new industries to the city, have improved industrial
conditions, and have exerted a beneficial influence upon the municipal
administration. Other business organizations are the Board of Trade,
devoted to the grain trade and kindred lines, the Employers'
Association, which seeks to maintain satisfactory relations between
employer and employed, the Builders' & Traders' Exchange, and the Credit
Men's Association.

_Administration._--Although the city received its first charter in 1806,
and another in 1815, the real power rested in the hands of the governor
and judges of the territory until 1824; the charters of 1824 and 1827
centred the government in a council and made the list of elective
officers long; the charter of 1827 was revised in 1857 and again in 1859
and the present charter dates from 1883. Under this charter only three
administrative officers are elected,--the mayor, the city clerk and the
city treasurer,--elections being biennial. The administration of the
city departments is largely in the hands of commissions. There is one
commissioner each, appointed by the mayor, for the parks and boulevards,
police and public works departments. The four members of the health
board are nominated by the governor and confirmed by the state senate.
The school board is an independent body, consisting of one elected
member from each ward holding office for four years, but the mayor has
the veto power over its proceedings as well as those of the common
council. In each case a two-thirds vote overrules his veto. The other
principal officers and commissions, appointed by the mayor and confirmed
by the council, are controller, corporation counsel, board of three
assessors, fire commission (four members), public lighting commission
(six members), water commission (five members), poor commission (four
members), and inspectors of the house of correction (four in number).
The members of the public library commission, six in number, are elected
by the board of education. Itemized estimates of expenses for the next
fiscal year are furnished by the different departments to the controller
in February. He transmits them to the common council with his
recommendations. The council has four weeks in which to consider them.
It may reduce or increase the amounts asked, and may add new items. The
budget then goes to the board of estimates, which has a month for its
consideration. This body consists of two members elected from each ward
and five elected at large. The mayor and heads of departments are
advisory members, and may speak but not vote. The members of the board
of estimates can hold no other office and they have no appointing power,
the intention being to keep them as free as possible from all political
motives and influences. They may reduce or cut out any estimates
submitted, but cannot increase any or add new ones. No bonds can be
issued without the assent of the board of estimates. The budget is
apportioned among twelve committees which have almost invariably given
close and conscientious examination to the actual needs of the
departments. A reduction of $1,000,000 to $1,500,000, without impairing
the service, has been a not unusual result of their deliberations.
Prudent management under this system has placed the city in the highest
rank financially. Its debt limit is 2% on the assessed valuation, and
even that low maximum is not often reached. The debt in 1907 was only
about $5,500,000, a smaller _per capita_ debt than that of any other
city of over 100,000 inhabitants in the country; the assessed valuation
was $330,000,000; the city tax, $14.70 on the thousand dollars of
assessed valuation. Both the council and the estimators are hampered in
their work by legislative interference. Nearly all the large salaries
and many of those of the second grade are made mandatory by the
legislature, which has also determined many affairs of a purely
administrative character.

Detroit has made three experiments with municipal ownership. On account
of inadequate and unsatisfactory service by a private company, the city
bought the water-works as long ago as 1836. The works have been twice
moved and enlargements have been made in advance of the needs of the
city. In 1907 there were six engines in the works with a pumping
capacity of 152,000,000 gallons daily. The daily average of water used
during the preceding year was 61,357,000 gallons. The water is pumped
from Lake St Clair and is of exceptional purity. The city began its own
public lighting in April 1895, having a large plant on the river near
the centre of the city. It lights the streets and public buildings, but
makes no provision for commercial business. The lighting is excellent,
and the cost is probably less than could be obtained from a private
company. The street lighting is done partly from pole and arm lights,
but largely from steel towers from 100 ft. to 180 ft. in height, with
strong reflected lights at the top. The city also owns two portable
asphalt plants, and thus makes a saving in the cost of street repairing
and resurfacing. With a view of effecting the reduction of street car
fares to three cents, the state legislature in 1899 passed an act for
purchasing or leasing the street railways of the city, but the Supreme
Court pronounced this act unconstitutional on the ground that, as the
constitution prohibited the state from engaging in a work of internal
improvement, the state could not empower a municipality to do so.
Certain test votes indicated an almost even division on the question of
municipal ownership of the railways.

_History._--Detroit was founded in 1701 by Antoine Laumet de la Mothe
Cadillac (c. 1661-1730), who had pointed out the importance of the place
as a strategic point for determining the control of the fur trade and
the possession of the North-west and had received assistance from the
French government soon after Robert Livingston (1654-1725), the
secretary of the Board of Indian Commissioners in New York, had urged
the English government to establish a fort at the same place. Cadillac
arrived on the 24th of July with about 100 followers. They at once built
a palisade fort about 200 ft. square S. of what is now Jefferson Avenue
and between Griswold and Shelby streets, and named it Fort Pontchartrain
in honour of the French colonial minister. Indians at once came to the
place in large numbers, but they soon complained of the high price of
French goods; there was serious contention between Cadillac and the
French Canadian Fur Company, to which a monopoly of the trade had been
granted, as well as bitter rivalry between him and the Jesuits. After
the several parties had begun to complain to the home government the
monopoly of the fur trade was transferred to Cadillac and he was
exhorted to cease quarrelling with the Jesuits. Although the
inhabitants then increased to 200 or more, dissatisfaction with the
paternal rule of the founder increased until 1710, when he was made
governor of Louisiana. The year before, the soldiers had been withdrawn;
by the second year after there was serious trouble with the Indians, and
for several years following the population was greatly reduced and the
post threatened with extinction. But in 1722, when the Mississippi
country was opened, the population once more increased, and again in
1748, when the settlement of the Ohio Valley began, the governor-general
of Canada offered special inducements to Frenchmen to settle at Detroit,
with the result that the population was soon more than 1000 and the
cultivation of farms in the vicinity was begun. In 1760, however, the
place was taken by the British under Colonel Robert Rogers and an
English element was introduced into the population which up to this time
had been almost exclusively French. Three years later, during the
conspiracy of Pontiac, the fort first narrowly escaped capture and then
suffered from a siege lasting from the 9th of May until the 12th of
October. Under English rule it continued from this time on as a military
post with its population usually reduced to less than 500. In 1778 a new
fort was built and named Fort Lernault, and during the War of
Independence the British sent forth from here several Indian expeditions
to ravage the frontiers. With the ratification of the treaty which
concluded that war the title to the post passed to the United States in
1783, but the post itself was not surrendered until the 11th of January
1796, in accordance with Jay's Treaty of 1794. It was then named Fort
Shelby; but in 1802 it was incorporated as a town and received its
present name. In 1805 all except one or two buildings were destroyed by
fire. General William Hull (1753-1825), a veteran of the War of American
Independence, governor of Michigan territory in 1805-1812, as commander
of the north-western army in 1812 occupied the city. Failing to hear
immediately of the declaration of war between the United States and
Great Britain, he was cut off from his supplies shipped by Lake Erie. He
made from Detroit on the 12th of July an awkward and futile advance into
Canada, which, if more vigorous, might have resulted in the capture of
Malden and the establishment of American troops in Canada, and then
retired to his fortifications. On the 16th of August 1812, without any
resistance and without consulting his officers, he surrendered the city
to General Brock, for reasons of humanity, and afterwards attempted to
justify himself by criticism of the War Department in general and in
particular of General Henry Dearborn's armistice with Prevost, which had
not included in its terms Hull, whom Dearborn had been sent out to
reinforce.[1] After Perry's victory on the 14th of September on Lake
Erie, Detroit on the 29th of September was again occupied by the forces
of the United States. Its growth was rather slow until 1830, but since
then its progress has been unimpeded. Detroit was the capital of
Michigan from 1805 to 1847.

  AUTHORITIES.--Silas Farmer, _The History of Detroit and Michigan_
  (Detroit, 1884 and 1889), and "Detroit, the Queen City," in L. P.
  Powell's _Historic Towns of the Western States_ (New York and London,
  1901); D. F. Wilcox, "Municipal Government in Michigan and Ohio," in
  _Columbia University Studies_ (New York, 1896); C. M. Burton,
  _"Cadillac's Village" or Detroit under Cadillac_ (Detroit, 1896);
  Francis Parkman, _A Half Century of Conflict_ (Boston, 1897); and _The
  Conspiracy of Pontiac_ (Boston, 1898); and the annual _Reports_ of the
  Detroit Board of Commerce (1904 sqq.).

[1] Hull was tried at Albany in 1814 by court martial, General Dearborn
presiding, was found guilty of treason, cowardice, neglect of duty and
unofficerlike conduct, and was sentenced to be shot; the president
remitted the sentence because of Hull's services in the Revolution.


DETTINGEN, a village of Germany in the kingdom of Bavaria, on the Main,
and on the Frankfort-on-Main-Aschaffenburg railway, 10 m. N.W. of
Aschaffenburg. It is memorable as the scene of a decisive battle on the
27th of June 1743, when the English, Hanoverians and Austrians (the
"Pragmatic army"), 42,000 men under the command of George II. of
England, routed the numerically superior French forces under the duc de
Noailles. It was in memory of this victory that Handel composed his
_Dettingen Te Deum_.


DEUCALION, in Greek legend, son of Prometheus, king of Phthia in
Thessaly, husband of Pyrrha, and father of Hellen, the mythical ancestor
of the Hellenic race. When Zeus had resolved to destroy all mankind by a
flood, Deucalion constructed a boat or ark, in which, after drifting
nine days and nights, he landed on Mount Parnassus (according to others,
Othrys, Aetna or Athos) with his wife. Having offered sacrifice and
inquired how to renew the human race, they were ordered to cast behind
them the "bones of the great mother," that is, the stones from the
hillside. The stones thrown by Deucalion became men, those thrown by
Pyrrha, women.

  See Apollodorus i. 7, 2; Ovid, _Metam._ i. 243-415; Apollonius Rhodius
  iii. 1085 ff.; H. Usener, _Die Sintflutsagen_ (1899).


DEUCE (a corruption of the Fr. _deux_, two), a term applied to the "two"
of any suit of cards, or of dice. It is also a term used in tennis when
both sides have each scored three points in a game, or five games in a
set; to win the game or set two points or games must then be won
consecutively. The earliest instances in English of the use of the slang
expression "the deuce," in exclamations and the like, date from the
middle of the 17th century. The meaning was similar to that of "plague"
or "mischief" in such phrases as "plague on you," "mischief take you"
and the like. The use of the word as an euphemism for "the devil" is
later. According to the _New English Dictionary_ the most probable
derivation is from a Low German _das daus_, i.e. the "deuce" in dice,
the lowest and therefore the most unlucky throw. The personification,
with a consequent change of gender, to _der daus_, came later. The word
has also been identified with the name of a giant or goblin in Teutonic
mythology.


DEUS, JOÃO DE (1830-1896), the greatest Portuguese poet of his
generation, was born at San Bartholomeu de Messines in the province of
Algarve on the 8th of March 1830. Matriculating in the faculty of law at
the university of Coimbra, he did not proceed to his degree but settled
in the city, dedicating himself wholly to the composition of verses,
which circulated among professors and undergraduates in manuscript
copies. In the volume of his art, as in the conduct of life, he
practised a rigorous self-control. He printed nothing previous to 1855,
and the first of his poems to appear in a separate form was _La Lata_,
in 1860. In 1862 he left Coimbra for Beja, where he was appointed editor
of _O Bejense_, the chief newspaper in the province of Alemtejo, and
four years later he edited the _Folha do Sul_. As the pungent satirical
verses entitled _Eleições_ prove, he was not an ardent politician, and,
though he was returned as Liberal deputy for the constituency of Silves
in 1869, he acted independently of all political parties and promptly
resigned his mandate. The renunciation implied in the act, which cut him
off from all advancement, is in accord with nearly all that is known of
his lofty character. In the year of his election as deputy, his friend
José Antonio Garcia Blanco collected from local journals the series of
poems, _Flores do campo_, which is supplemented by the _Ramo de flores_
(1869). This is João de Deus's masterpiece. _Pires de Marmalada_ (1869)
is an improvisation of no great merit. The four theatrical
pieces--_Amemos o nosso proximo_, _Ser apresentado_, _Ensaio de
Casamento_, and _A Viúva inconsolavel_--are prose translations from
Méry, cleverly done, but not worth the doing. _Horacio e Lydia_ (1872),
a translation from Ronsard, is a good example of artifice in
manipulating that dangerously monotonous measure, the Portuguese
couplet. As an indication of a strong spiritual reaction three prose
fragments (1873)--_Anna, Mãe de Maria_, _A Virgem Maria_ and _A Mulher
do Levita de Ephrain_--translated from Darboy's _Femmes de la Bible_,
are full of significance. The _Folhas soltas_ (1876) is a collection of
verse in the manner of _Flores do campo_, brilliantly effective and
exquisitely refined. Within the next few years the writer turned his
attention to educational problems, and in his _Cartilha maternal_ (1876)
first expressed the conclusions to which his study of Pestalozzi and
Fröbel had led him. This patriotic, pedagogical apostolate was a
misfortune for Portuguese literature; his educational mission absorbed
João de Deus completely, and is responsible for numerous controversial
letters, for a translation of Théodore-Henri Barrau's treatise, _Des
devoirs des enfants envers leurs parents_, for a prosodic dictionary
and for many other publications of no literary value. A copy of verses
in Antonio Vieira's _Grinalda de Maria_ (1877), the _Loas á Virgem_
(1878) and the _Proverbios de Salomão_ are evidence of a complete return
to orthodoxy during the poet's last years. By a lamentable error of
judgment some worthless pornographic verses entitled _Cryptinas_ have
been inserted in the completest edition of João de Deus's poems--_Campo
de Flores_ (Lisbon, 1893). He died at Lisbon on the 11th of January
1896, was accorded a public funeral and was buried in the National
Pantheon, the Jeronymite church at Belem, where repose the remains of
Camoens, Herculano and Garrett. His scattered minor prose writings and
correspondence have been posthumously published by Dr Theophilo Braga
(Lisbon, 1898).

Next to Camoens and perhaps Garrett, no Portuguese poet has been more
widely read, more profoundly admired than João de Deus; yet no poet in
any country has been more indifferent to public opinion and more
deliberately careless of personal fame. He is not responsible for any
single edition of his poems, which were put together by pious but
ill-informed enthusiasts, who ascribed to him verses that he had not
written; he kept no copies of his compositions, seldom troubled to write
them himself, and was content for the most part to dictate them to
others. He has no great intellectual force, no philosophic doctrine, is
limited in theme as in outlook, is curiously uncertain in his touch,
often marring a fine poem with a slovenly rhyme or with a misplaced
accent; and, on the only occasion when he was induced to revise a set of
proofs, his alterations were nearly all for the worse. And yet, though
he never appealed to the patriotic spirit, though he wrote nothing at
all comparable in force or majesty to the restrained splendour of _Os
Lusiadas_, the popular instinct which links his name with that of his
great predecessor is eminently just. For Camoens was his model; not the
Camoens of the epic, but the Camoens of the lyrics and the sonnets,
where the passion of tenderness finds its supreme utterance. Braga has
noted five stages of development in João de Deus's artistic life--the
imitative, the idyllic, the lyric, the pessimistic and the devout
phases. Under each of these divisions is included much that is of
extreme interest, especially to contemporaries who have passed through
the same succession of emotional experience, and it is highly probable
that _Caturras_ and _Gaspar_, pieces as witty as anything in Bocage but
free from Bocage's coarse impiety, will always interest literary
students. But it is as the singer of love that João de Deus will delight
posterity as he delighted his own generation. The elegiac music of
_Rachel_ and of _Marina_, the melancholy of _Adeus_ and of _Remoinho_,
the tenderness and sincerity of _Meu casta lirio_, of _Lagrima celeste_,
of _Descalça_ and a score more songs are distinguished by the large,
vital simplicity which withstands time. It is precisely in the quality
of unstudied simplicity that João de Deus is incomparably strong. The
temptations to a display of virtuosity are almost irresistible for a
Portuguese poet; he has the tradition of virtuosity in his blood, he has
before him the example of all contemporaries, and he has at hand an
instrument of wonderful sonority and compass. Yet not once is João de
Deus clamorous or rhetorical, not once does he indulge in idle ornament.
His prevailing note is that of exquisite sweetness and of reverent
purity; yet with all his caressing softness he is never sentimental,
and, though he has not the strength for a long fight, emotion has seldom
been set to more delicate music. Had he included among his other gifts
the gift of selection, had he continued the poetic discipline of his
youth instead of dedicating his powers to a task which, well as he
performed it, might have been done no less well by a much lesser man,
there is scarcely any height to which he might not have risen.

  See also Maxime Formont, _Le Mouvement poétique contemporain en
  Portugal_ (Lyon, 1892).                                (J. F.-K.)


DEUTERONOMY, the name of one of the books of the Old Testament. This
book was long the storm-centre of Pentateuchal criticism, orthodox
scholars boldly asserting that any who questioned its Mosaic authorship
reduced it to the level of a pious fraud. But Biblical facts have at
last triumphed over tradition, and the non-Mosaic authorship of
Deuteronomy is now a commonplace of criticism. It is still instructive,
however, to note the successive phases through which scholarly opinion
regarding the composition and date of his book has passed.

In the 17th century the characteristics which so clearly mark off
Deuteronomy from the other four books of the Pentateuch were frankly
recognized, but the most advanced critics of that age were inclined to
pronounce it the earliest and most authentic of the five. In the
beginning of the 19th century de Wette startled the religious world by
declaring that Deuteronomy, so far from being Mosaic, was not known till
the time of Josiah. This theory he founded on 2 Kings xxii.; and ever
since, this chapter has been one of the recognized foci of Biblical
criticism. The only other single chapter of the Bible which is
responsible for having brought about a somewhat similar revolution in
critical opinion is Ezek. xliv. From this chapter, some seventy years
after de Wette's discovery, Wellhausen with equal acumen inferred that
Leviticus was not known to Ezekiel, the priest, and therefore could not
have been in existence in his day; for had Leviticus been the recognized
Law-book of his nation Ezekiel could not have represented as a
degradation the very position which that Law-book described as a special
honour conferred on the Levites by Yahweh himself. Hence Leviticus, so
far from belonging to an earlier stratum of the Pentateuch than
Deuteronomy, as de Wette thought, must belong to a much later stratum,
and be at least exilic, if not post-exilic.

The title "Deuteronomy" is due to a mistranslation by the Septuagint of
the clause in chap. xvii. 18, rendered "and he shall write out for
himself this Deuteronomy." The Hebrew really means "and he [the king]
shall write out for himself a copy of this law," where there is not the
slightest suggestion that the author intended to describe "this law"
delivered on the plains of Moab as a second code in contradistinction to
the first code given on Sinai thirty-eight years earlier. Moreover the
phrase "this law" is so ambiguous as to raise a much greater difficulty
than that caused by the Greek mistranslation of the Hebrew word for
"copy." How much does "this law" include? It was long supposed to mean
the whole of our present Deuteronomy; indeed, it is on that supposition
that the traditional view of the Mosaic authorship is based. But the
context alone can determine the question; and that is often so ambiguous
that a sure inference is impossible. We may safely assert, however, that
nowhere need "this law" mean the whole book. In fact, it invariably
means very much less, and sometimes, as in xxvii. 3, 8, so little that
it could all be engraved in large letters on a few plastered stones set
up beside an altar.

Deuteronomy is not the work of any single writer but the result of a
long process of development. The fact that it is legislative as well as
hortatory is enough to prove this, for most of the laws it contains are
found elsewhere in the Pentateuch, sometimes in less developed,
sometimes in more developed forms, a fact which is conclusive proof of
prolonged historical development. According to the all-pervading law of
evolution, the less complex form must have preceded the more complex.
Still, the book does bear the stamp of one master-mind. Its style is as
easily recognized as that of Deutero-Isaiah, being as remarkable for its
copious diction as for its depths of moral and religious feeling.

The original Deuteronomy, D, read to King Josiah, cannot have been so
large as our present book, for not only could it be read at a single
sitting, but it could be easily read twice in one day. On the day it was
found, Shaphan first read it himself, and then went to the king and read
it aloud to him. But perhaps the most conclusive proof of its brevity is
that it was read publicly to the assembled people immediately before
they, as well as their king, pledged themselves to obey it; and not a
word is said as to the task of reading it aloud, so as to be heard by
such a great multitude, being long or difficult.

The legislative part of D consists of fifteen chapters (xii.-xxvi.),
which, however, contain many later insertions. But the impression made
upon Josiah by what he heard was far too deep to have been produced by
the legislative part alone. The king must have listened to the curses as
well as the blessings in chap, xxviii., and no doubt also to the
exhortations in chaps. v.-xi. Hence we may conclude that the original
book consisted of a central mass of religious, civil and social laws,
preceded by a hortatory introduction and followed by an effective
peroration. The book read to Josiah must therefore have comprised most
of what is found in Deut. v.-xxvi., xxvii. 9, 10 and xxviii. But
something like two centuries elapsed before the book reached its present
form, for in the closing chapter, as well as elsewhere, e.g. i. 41-43
(where the joining is not so deftly done as usual) and xxxii. 48-52,
there are undoubted traces of the Priestly Code, P, which is generally
acknowledged to be post-exilic.

The following is an analysis of the main divisions of the book as we now
have it. There are two introductions, the first i.-iv. 44, more
historical than hortatory; the second v.-xi., more hortatory than
historical. These may at first have been prefixed to separate editions
of the legislative portion, but were eventually combined. Then, before D
was united to P, five appendices of very various dates and embracing
poetry as well as prose, were added so as to give a fuller account of
the last days of Moses and thus lead up to the narrative of his death
with which the book closes. (1) Chap. xxvii., where the elders of Israel
are introduced for the first time as acting along with Moses (xxvii. 1)
and then the priests, the Levites (xxvii. 9). Some of the curses refer
to laws given not in D but in Lev. xxx., so that the date of this
chapter must be later than Leviticus or at any rate than the laws
codified in the Law of Holiness (Lev. xvii.-xxvi.). (2) The second
appendix, chaps, xxix.-xxxi. 29, xxxii. 45-47, gives us the farewell
address of Moses and is certainly later than D. Moses is represented as
speaking not with any hope of preventing Israel's apostasy but because
he knows that the people will eventually prove apostate (xxxi. 29), a
point of view very different from D's. (3) The Song of Moses, chap.
xxxii. That this didactic poem must have been written late in the
nation's history, and not at its very beginning, is evident from v. 7:
"Remember the days of old, Consider the years of many generations." Such
words cannot be interpreted so as to fit the lips of Moses. It must have
been composed in a time of natural gloom and depression, after Yahweh's
anger had been provoked by "a very froward generation," certainly not
before the Assyrian Empire had loomed up against the political horizon,
aggressive and menacing. Some critics bring the date down even to the
time of Jeremiah and Ezekiel. (4) The Blessing of Moses, chap, xxxiii.
The first line proves that this poem is not by D, who speaks invariably
of Horeb, never of Sinai. The situation depicted is in striking contrast
with that of the Song. Everything is bright because of promises
fulfilled, and the future bids fair to be brighter still. Bruston
maintains with reason that the Blessing, strictly so called, consists
only of vv. 6-25, and has been inserted in a Psalm celebrating the
goodness of Jehovah to his people on their entrance into Canaan (vv.
1-5, 26-29). The special prominence given to Joseph (Ephraim and
Manasseh) in vv. 13-17 has led many critics to assign this poem to the
time of the greatest warrior-king of Northern Israel, Jeroboam II. (5)
The account of Moses' death, chap. xxxiv. This appendix, containing, as
it does, manifest traces of P, proves that even Deuteronomy was not put
into its present form until after the exile.

From the many coincidences between D and the Book of the Covenant (Ex.
xx.-xxiii.) it is clear that D was acquainted with E, the prophetic
narrative of the Northern kingdom; but it is not quite clear whether D
knew E as an independent work, or after its combination with J, the
somewhat earlier prophetic narrative of the Southern kingdom, the
combined form of which is now indicated by the symbol JE. Kittel
certainly puts it too strongly when he asserts that D quotes always from
E and never from J, for some of the passages alluded to in D may just as
readily be ascribed to J as to E, cf. Deut. i. 7 and Gen. xv. 18; Deut.
x. 14 and Ex. xxxiv. 1-4. Consequently D must have been written
certainly after E and possibly after E was combined with J.

In Amos, Hosea and Isaiah there are no traces of D's ideas, whereas in
Jeremiah and Ezekiel their influence is everywhere manifest. Hence this
school of thought arose between the age of Isaiah and that of Jeremiah;
but how long D itself may have been in existence before it was read in
622 to Josiah cannot be determined with certainty. Many argue that D was
written immediately before it was found and that, in fact, it was put
into the temple for the purpose of being "found." This theory gives some
plausibility to the charge that the book is a pious fraud. But the
narrative in 2 Kings xxii. warrants no such inference. The more natural
explanation is that it was written not in the early years of Josiah's
reign, and with the cognizance of the temple priests then in office, but
some time during the long reign of Manasseh, probably when his policy
was most reactionary and when he favoured the worship of the "host of
heaven" and set up altars to strange gods in Jerusalem itself. This
explains why the author did not publish his work immediately, but placed
it where he hoped it would be safely preserved till opportunity should
arise for its publication. One need not suppose that he actually foresaw
how favourable that opportunity would prove, and that, as soon as
discovered, his work would be promulgated as law by the king and
willingly accepted by the people. The author believed that everything he
wrote was in full accordance with the mind of Moses, and would
contribute to the national weal of Yahweh's covenant people, and
therefore he did not scruple to represent Moses as the speaker. It is
not to be expected that modern scholars should be able to fix the exact
year or even decade in which such a book was written. It is enough to
determine with something like probability the century or half-century
which best fits its historical data; and these appear to point to the
reign of Manasseh.

Between D and P there are no verbal parallels; but in the historical
résumés JE is followed closely, whole clauses and even verses being
copied practically verbatim. As Dr Driver points out in his careful
analysis, there are only three facts in D which are not also found in
JE, viz. the number of the spies, the number of souls that went down
into Egypt with Jacob, and the ark being made of acacia wood. But even
these may have been in J or E originally, and left out when JE was
combined with P. Steuernagel divides the legal as well as the hortatory
parts of D between two authors, one of whom uses the 2nd person plural
when addressing Israel, and the other the 2nd person singular; but as a
similar alternation is constantly found in writings universally
acknowledged to be by the same author, this clue seems anything but
trustworthy, depending as it does on the presence or absence of a single
Hebrew letter, and resulting, as it frequently does, in the division of
verses which otherwise seem to be from the same pen (cf. xx. 2). The
inference as to diversity of authorship is much more conclusive when
difference of standpoint can be proved, cf. v. 3, xi. 2 ff. with viii.
2. The first two passages represent Moses as addressing the generation
that was alive at Horeb, whereas the last represents him as speaking to
those who were about to pass over Jordan a full generation later; and it
may well be that the one author may, in the historical and hortatory
parts, have preferred the 2nd plural and the other the 2nd singular;
without the further inference being justified that every law in which
the 2nd singular is used must be assigned to the latter, and every law
in which the 2nd plural occurs must be due to the former.

The law of the Single Sanctuary, one of D's outstanding characteristics,
is, for him, an innovation, but an innovation towards which events had
long been tending. 2 Kings xxiii. 9 shows that even the zeal of Josiah
could not carry out the instructions laid down in D xviii. 6-8. Josiah's
acceptance of D made it the first canonical book of scripture. Thus the
religion of Judah became henceforward a religion which enabled its
adherents to learn from a book exactly what was required of them. D
requires the destruction not only of the high places and the idols, but
of the Asheras (wooden posts) and the Mazzebas (stone pillars) often set
up beside the altar of Jehovah (xvi. 21). These reforms made too heavy
demands upon the people, as was proved by the reaction which set in at
Josiah's death. Indeed the country people would look on the destruction
of the high places with their Asheras and Mazzebas as sacrilege and
would consider Josiah's death in battle as a divine punishment for his
sacrilegious deeds. On the other hand, the destruction of Jerusalem and
the exile of the people would appear to those who had obeyed D's
instructions as a well-merited punishment for national apostasy.

Moreover, D regarded religion as of the utmost moment to each individual
Israelite; and it is certainly not by accident that the declaration of
the individual's duty towards God immediately follows the emphatic
intimation to Israel of Yahweh's unity. "Hear, O Israel, Yahweh is our
God, Yahweh is one: and thou shalt love Yahweh thy God with all thine
heart and with all thy soul and with all thy strength" (vi. 4, 5).

In estimating the religious value of Deuteronomy it should never be
forgotten that upon this passage the greatest eulogy ever pronounced on
any scripture was pronounced by Christ himself, when he said "on these
words hang all the law and the prophets," and it is also well to
remember that when tempted in the wilderness he repelled each suggestion
of the Tempter by a quotation from Deuteronomy.

Nevertheless even such a writer as D could not escape the influence of
the age and atmosphere in which he lived; and despite the spirit of love
which breathes so strongly throughout the book, especially for the poor,
the widow and the fatherless, the stranger and the homeless Levite
(xxiv. 10-22), and the humanity shown towards both beasts and birds
(xxii. 1, 4, 6 f., xxv. 4), there are elements in D which go far to
explain the intense exclusiveness and the religious intolerance
characteristic of Judaism. Should a man's son or friend dear to him as
his own soul seek to tempt him from the faith of his fathers, D's
pitiless order to that man is "Thou shalt surely kill him; thine hand
shall be first upon him to put him to death." From this single instance
we see not only how far mankind has travelled along the path of
religious toleration since Deuteronomy was written, but also how very
far the criticism implied in Christ's method of dealing with what "was
said to them of old time" may be legitimately carried. (J. A. P.*)


DEUTSCH, IMMANUEL OSCAR MENAHEM (1829-1873), German oriental scholar,
was born on the 28th of October 1829, at Neisse in Prussian Silesia, of
Jewish extraction. On reaching his sixteenth year he began his studies
at the university of Berlin, paying special attention to theology and
the Talmud. He also mastered the English language and studied English
literature. In 1855 Deutsch was appointed assistant in the library of
the British Museum. He worked intensely on the Talmud and contributed no
less than 190 papers to _Chambers's Encyclopaedia_, in addition to
essays in Kitto's and Smith's Biblical Dictionaries, and articles in
periodicals. In October 1867 his article on "The Talmud," published in
the _Quarterly Review_, made him known. It was translated into French,
German, Russian, Swedish, Dutch and Danish. He died at Alexandria on the
12th of May 1873.

  His _Literary Remains_, edited by Lady Strangford, were published in
  1874, consisting of nineteen papers on such subjects as "The Talmud,"
  "Islam," "Semitic Culture," "Egypt, Ancient and Modern," "Semitic
  Languages," "The Targums," "The Samaritan Pentateuch," and "Arabic
  Poetry."


DEUTSCHKRONE, a town of Germany, kingdom of Prussia, between the two
lakes of Arens and Radau, 15 m. N.W. of Schneidemühl, a railway junction
60 m. north of Posen. Pop. (1905) 7282. It is the seat of the public
offices for the district, possesses an Evangelical and a Roman Catholic
church, a synagogue, and a gymnasium established in the old Jesuit
college, and has manufactures of machinery, woollens, tiles, brandy and
beer.


DEUTZ (anc. _Divitio_), formerly an independent town of Germany, in the
Prussian Rhine Province, on the right bank of the Rhine, opposite to
Cologne, with which it has been incorporated since 1888. It contains the
church of St Heribert, built in the 17th century, cavalry barracks,
artillery magazines, and gas, porcelain, machine and carriage factories.
It has a handsome railway station on the banks of the Rhine, negotiating
the local traffic with Elberfeld and Königswinter. The fortifications of
the town form part of the defences of Cologne. To the east is the
manufacturing suburb of Kalk.

The old castle in Deutz was in 1002 made a Benedictine monastery by
Heribert, archbishop of Cologne. Permission to fortify the town was in
1230 granted to the citizens by the archbishop of Cologne, between whom
and the counts of Berg it was in 1240 divided. It was burnt in 1376,
1445 and 1583; and in 1678, after the peace of Nijmwegen, the
fortifications were dismantled; rebuilt in 1816, they were again razed
in 1888.


DEUX-SÈVRES, an inland department of western France, formed in 1790
mainly of the three districts of Poitou, Thouarsais, Gâtine and
Niortais, added to a small portion of Saintonge and a still smaller
portion of Aunis. Area, 2337 sq. m. Pop. (1906) 339,466. It is bounded
N. by Maine-et-Loire, E. by Vienne, S.E. by Charente, S. by
Charente-Inférieure and W. by Vendée. The department takes its name from
two rivers--the Sèvre of Niort which traverses the southern portion, and
the Sèvre of Nantes (an affluent of the Loire) which drains the
north-west. There are three regions--the Gâtine, occupying the north and
centre of the department, the Plaine in the south and the
Marais,--distinguished by their geological character and their general
physical appearance. The Gâtine, formed of primitive rocks (granite and
schists), is the continuation of the "Bocage" of Vendée and
Maine-et-Loire. Its surface is irregular and covered with hedges and
clumps of wood or forests. The systematic application of lime has much
improved the soil, which is naturally poor. The Plaine, resting on
oolite limestone, is treeless but fertile. The Marais, a low-lying
district in the extreme south-west, consists of alluvial clays which also
are extremely productive when properly drained. The highest points,
several of which exceed 700 ft., are found in a line of hills which
begins in the centre of the department, to the south of Parthenay, and
stretches north-west into the neighbouring department of Vendée. It
divides the region drained by the Sèvre Nantaise and the Thouet (both
affluents of the Loire) in the north from the basins of the Sèvre
Niortaise and the Charente in the south. The climate is mild, the annual
temperature at Niort being 54° Fahr., and the rainfall nearly 25 in. The
winters are colder in the Gâtine, the summers warmer in the Plaine.

Three-quarters of the entire area of Deux-Sèvres, which is primarily an
agricultural department, consists of arable land. Wheat and oats are the
main cereals. Potatoes and mangold-wurzels are the chief root-crops.
Niort is a centre for the growing Of vegetables (onions, asparagus,
artichokes, &c.) and of angelica. Considerable quantities of beetroot
are raised to supply the distilleries of Melle. Colza, hemp, rape and
flax are also cultivated. Vineyards are numerous in the neighbourhood of
Bressuire in the north, and of Niort and Melle in the south. The
department is well known for the Parthenay breed of cattle and the
Poitou breed of horses; and the mules reared in the southern
arrondissements are much sought after both in France and in Spain. The
system of co-operative dairying is practised in some localities. The
apple-trees of the Gâtine and the walnut-trees of the Plaine bring a
good return. Coal is mined, and the department produces building-stone
and lime. A leading industry is the manufacture of textiles (serges,
druggets, linen, handkerchiefs, flannels, swan-skins and knitted goods).
Tanning and leather-dressing are carried on at Niort and other places,
and gloves are made at Niort. Wool and cotton spinning, hat and shoe
making, distilling, brewing, flour-milling and oil-refining are also
main industries. The department exports cattle and sheep to Paris and
Poitiers; also cereals, oils, wines, vegetables and its industrial
products.

The Sèvre Niortaise and its tributary the Mignon furnish 19 m. of
navigable waterway. The department is served by the Ouest-État railway.
It contains a large proportion of Protestants, especially in the
south-east. The four arrondissements are Niort, Bressuire, Melle and
Parthenay; the cantons number 31, and the communes 356. Deux-Sèvres is
part of the region of the IX. army corps, and of the diocese and the
académie (educational circumscription) of Poitiers, where also is its
court of appeal.

Niort (the capital), Bressuire, Melle, Parthenay, St Maixent, Thouars
and Oiron are the principal places in the department. Several other
towns contain features of interest. Among these are Airvault, where
there is a church of the 12th and 14th centuries which once belonged to
the abbey of St Pierre, and an ancient bridge built by the monks;
Celles-sur-Belle, where there is an old church rebuilt by Louis XI., and
again in the 17th century; and St Jouin-de-Marnes, with a fine
Romanesque church with Gothic restoration, which belonged to one of the
most ancient abbeys of Gaul.


DEVA (Sanskrit "heavenly"), in Hindu and Buddhist mythology, spirits of
the light and air, and minor deities generally beneficent. In Persian
mythology, however, the word is used for evil spirits or demons.
According to Zoroaster the devas were created by Ahriman.


DEVA (mod. _Chester_), a Roman legionary fortress in Britain on the Dee.
It was occupied by Roman troops about A.D. 48 and held probably till the
end of the Roman dominion. Its garrison was the Legio XX. Valeria
Victrix, with which another legion (II. Adjutrix) was associated for a
few years, about A.D. 75-85. It never developed, like many Roman
legionary fortresses, into a town, but remained military throughout.
Parts of its north and east walls (from Morgan's Mount to Peppergate)
and numerous inscriptions remain to indicate its character and area.

  See F. J. Haverfield, _Catalogue of the Grosvenor Museum, Chester_
  (Chester, 1900), Introduction.


DEVADATTA, the son of Suklodana, who was younger brother to the father
of the Buddha (_Mah[=a]vastu_, iii. 76). Both he and his brother
[=A]nanda, who were considerably younger than the Buddha, joined the
brotherhood in the twentieth year of the Buddha's ministry. Four other
cousins of theirs, chiefs of the S[=a]kiya clan, and a barber named
Up[=a]li, were admitted to the order at the same time; and at their own
request the barber was admitted first, so that as their senior in the
order he should take precedence of them (_Vinaya Texts_, iii. 228). All
the others continued loyal disciples, but Devadatta, fifteen years
afterwards, having gained over the crown prince of Magadha,
Aj[=a]tasattu, to his side, made a formal proposition, at the meeting of
the order, that the Buddha should retire, and hand over the leadership
to him, Devadatta (_Vinaya Texts_, iii. 238; _J[=a]taka_, i. 142). This
proposal was rejected, and Devadatta is said in the tradition to have
successfully instigated the prince to the execution of his aged father
and to have made three abortive attempts to bring about the death of the
Buddha (_Vinaya Texts_, iii. 241-250; _J[=a]taka_, vi. 131), shortly
afterwards, relying upon the feeling of the people in favour of
asceticism, he brought forward four propositions for ascetic rules to be
imposed on the order. These being refused, he appealed to the people,
started an order of his own, and gained over 500 of the Buddha's
community to join in the secession. We hear nothing further about the
success or otherwise of the new order, but it may possibly be referred
to under the name of the Gotamakas, in the _Anguttara_ (see _Dialogues
of the Buddha_ i. 222), for Devadatta's family name was Gotama. But his
community was certainly still in existence in the 4th century A.D., for
it is especially mentioned by Fa Hien, the Chinese pilgrim (Legge's
translation, p. 62). And it possibly lasted till the 7th century, for
Hsüan Tsang mentions that in a monastery in Bengal the monks then
followed a certain regulation of Devadatta's (T. Watters, _On Yuan
Chwang_, ii. 191). There is no mention in the canon as to how or when
Devadatta died; but the commentary on the _J[=a]taka_, written in the
5th century A.D., has preserved a tradition that he was swallowed up by
the earth near S[=a]vatthi, when on his way to ask pardon of the Buddha
(_J[=a]taka_, iv. 158). The spot where this occurred was shown to both
the pilgrims just mentioned (Fa Hien, loc. cit. p. 60; and T. Watters,
_On Yuan Chwang_, i. 390). It is a striking example of the way in which
such legends grow, that it is only the latest of these authorities,
Hsüan Tsang, who says that, though ostensibly approaching the Buddha
with a view to reconciliation, Devadatta had concealed poison in his
nail with the object of murdering the Buddha.

  AUTHORITIES.--_Vinaya Texts_, translated by Rhys Davids and H.
  Oldenberg (3 vols., Oxford, 1881-1885); _The J[=a]taka_, edited by V.
  Fausböll (7 vols., London, 1877-1897); T. Watters, _On Yuan Chwang_
  (ed. Rhys Davids and Bushell, 2 vols., London, 1904-1905); _Fa Hian_,
  translated by J. Legge (Oxford, 1886); _Mah[=a]vastu_ (ed. Tenant, 3
  vols., Paris, 1882-1897).                               (T. W. R. D.)


DEVAPRAYAG (DEOPRAYAG), a village in Tehri State of the United
Provinces, India. It is situated at the spot where the rivers Alaknanda
and Bhagirathi unite and form the Ganges, and as one of the five sacred
confluences in the hills is a great place of pilgrimage for devout
Hindus. Devaprayag stands at an elevation of 2265 ft. on the side of a
hill which rises above it 800 ft. On a terrace in the upper part of the
village is the temple of Raghunath, built of huge uncemented stones,
pyramidical in form and capped by a white cupola.


DEVENS, CHARLES (1820-1891), American lawyer and jurist, was born in
Charlestown, Massachusetts, on the 4th of April 1820. He graduated at
Harvard College in 1838, and at the Harvard law school in 1840, and was
admitted to the bar in Franklin county, Mass., where he practised from
1841 to 1849. In the year 1848 he was a Whig member of the state senate,
and from 1849 to 1853 was United States marshal for Massachusetts, in
which capacity he was called upon in 1851 to remand the fugitive slave,
Thomas Sims, to slavery. This he felt constrained to do, much against
his personal desire; and subsequently he attempted in vain to purchase
Sims's freedom, and many years later appointed him to a position in the
department of justice at Washington. Devens practised law at Worcester
from 1853 until 1861, and throughout the Civil War served in the Federal
army, becoming colonel of volunteers in July 1861 and brigadier-general
of volunteers in April 1862. At the battle of Ball's Bluff (1861) he was
severely wounded; he was again wounded at Fair Oaks (1862) and at
Chancellorsville (1863), where he commanded a division. He later
distinguished himself at Cold Harbor, and commanded a division in
Grant's final campaign in Virginia (1864-65), his troops being the first
to occupy Richmond after its fall. Breveted major-general in 1865, he
remained in the army for a year as commander of the military district of
Charleston, South Carolina. He was a judge of the Massachusetts superior
court from 1867 to 1873, and was an associate justice of the supreme
court of the state from 1873 to 1877, and again from 1881 to 1891. From
1877 to 1881 he was attorney-general of the United States in the cabinet
of President Hayes. He died at Boston, Mass., on the 7th of January
1891.

  See his _Orations and Addresses_, with a memoir by John Codman Ropes
  (Boston, 1891).


DEVENTER, a town in the province of Overysel, Holland, on the right bank
of the Ysel, at the confluence of the Schipbeek, and a junction station
10 m. N. of Zutphen by rail. It is also connected by steam tramway S.E.
with Brokulo. Pop. (1900) 26,212. Deventer is a neat and prosperous town
situated in the midst of prettily wooded environs, and containing many
curious old buildings. There are three churches of special interest: the
Groote Kerk (St Lebuinus), which dates from 1334, and occupies the site
of an older structure of which the 11th-century crypt remains; the Roman
Catholic Broederkerk, or Brothers' Church, containing among its relics
three ancient gospels said to have been written by St Lebuinus (Lebwin),
the English apostle of the Frisians and Westphalians (d. c. 773); and
the Bergkerk, dedicated in 1206, which has two late Romanesque towers.
The town hall (1693) contains a remarkable painting of the town council
by Terburg. In the fine square called the Brink is the old weigh-house,
now a school (gymnasium), built in 1528, with a large external staircase
(1644). The gymnasium is descended from the Latin school of which the
celebrated Alexander Hegius was master in the third quarter of the 15th
century, when the young Erasmus was sent to it, and at which Adrian
Floreizoon, afterwards Pope Adrian VI., is said to have been a pupil
about the same time. Another famous educational institution was the
"Athenaeum" or high school, founded in 1630, at which Henri Renery (d.
1639) taught philosophy, while Johann Friedrich Gronov (Gronovius)
(1611-1671) taught rhetoric and history in the middle of the same
century. The "Athenaeum" disappeared in 1876. In modern times Deventer
possessed a famous teacher in Dr Burgersdyk (d. 1900), the Dutch
translator of Shakespeare. The town library, also called the library of
the Athenaeum, includes many MSS. and _incunabula_, and a 13th-century
copy of _Reynard the Fox_. The archives of the town are of considerable
value. Besides a considerable agricultural trade, Deventer has important
iron foundries and carpet factories (the royal manufactory of Smyrna
carpets being especially famous); while cotton-printing, rope-making and
the weaving of woollens and silks are also carried on. A public official
is appointed to supervise the proper making of a form of gingerbread
known as "_Deventer Koek_," which has a reputation throughout Holland.
In the church of Bathmen, a village 5 m. E. of Deventer, some
14th-century frescoes were discovered in 1870.

In the 14th century Deventer was the centre of the famous religious and
educational movement associated with the name of GERHARD GROOT (q.v.),
who was a native of the town (see BROTHERS OF COMMON LIFE).


DE VERE, AUBREY THOMAS (1814-1902), Irish poet and critic, was born at
Curragh Chase, Co. Limerick, on the 10th of January 1814, being the
third son of Sir Aubrey de Vere Hunt (1788-1846). In 1832 his father
dropped the final name by royal licence. Sir Aubrey was himself a poet.
Wordsworth called his sonnets the "most perfect of the age." These and
his drama, _Mary Tudor_, were published by his son in 1875 and 1884.
Aubrey de Vere was educated at Trinity College, Dublin, and in his
twenty-eighth year published _The Waldenses_, which he followed up in
the next year by _The Search after Proserpine_. Thenceforward he was
continually engaged, till his death on the 20th of January 1902, in the
production of poetry and criticism. His best-known works are: in verse,
_The Sisters_ (1861); _The Infant Bridal_ (1864); _Irish Odes_ (1869);
_Legends of St Patrick_ (1872); and _Legends of the Saxon Saints_
(1879); and in prose, _Essays chiefly on Poetry_ (1887); and _Essays
chiefly Literary and Ethical_ (1889). He also wrote a picturesque volume
of travel-sketches, and two dramas in verse, _Alexander the Great_
(1874); and _St Thomas of Canterbury_ (1876); both of which, though they
contain fine passages, suffer from diffuseness and a lack of dramatic
spirit. The characteristics of Aubrey de Vere's poetry are "high
seriousness" and a fine religious enthusiasm. His research in questions
of faith led him to the Roman Church; and in many of his poems, notably
in the volume of sonnets called _St Peter's Chains_ (1888), he made rich
additions to devotional verse. He was a disciple of Wordsworth, whose
calm meditative serenity he often echoed with great felicity; and his
affection for Greek poetry, truly felt and understood, gave dignity and
weight to his own versions of mythological idylls. But perhaps he will
be chiefly remembered for the impulse which he gave to the study of
Celtic legend and literature. In this direction he has had many
followers, who have sometimes assumed the appearance of pioneers; but
after Matthew Arnold's fine lecture on "Celtic Literature," nothing
perhaps did more to help the Celtic revival than Aubrey de Vere's tender
insight into the Irish character, and his stirring reproductions of the
early Irish epic poetry.

  A volume of _Selections_ from his poems was edited in 1894 (New York
  and London) by G. E. Woodberry.


DEVICE, a scheme, plan, simple mechanical contrivance; also a pattern or
design, particularly an heraldic design or emblem, often combined with a
motto or legend. "Device" and its doublet "devise" come from the two Old
French forms _devis_ and _devise_ of the Latin _divisa_, things divided,
from _dividere_, to separate, used in the sense of to arrange, set out,
apportion. "Devise," as a substantive, is now only used as a legal term
for a disposition of property by will, by a modern convention restricted
to a disposition of real property, the term "bequest" being used of
personalty (see WILL). This use is directly due to the Medieval Latin
meaning of _dividere_ = _testamento disponere_. In its verbal form,
"devise" is used not only in the legal sense, but also in the sense of
to plan, arrange, scheme.


DEVIL (Gr. [Greek: diabolos], "slanderer," from [Greek: diaballein], to
slander), the generic name for a spirit of evil, especially the supreme
spirit of evil, the foe of God and man. The word is used for minor evil
spirits in much the same sense as "demon." From the various
characteristics associated with this idea, the term has come to be
applied by analogy in many different senses. From the idea of evil as
degraded, contemptible and doomed to failure, the term is applied to
persons in evil plight, or of slight consideration. In English legal
phraseology "devil" and "devilling" are used of barristers who act as
substitutes for others. Any remuneration which the legal "devil" may
receive is purely a matter of private arrangement between them. In the
chancery division such remuneration is generally in the proportion of
one half of the fee which the client pays; "in the king's bench division
remuneration for 'devilling' of briefs or assisting in drafting and
opinions is not common" (see _Annual Practice_, 1907, p. 717). In a
similar sense an author may have his materials collected and arranged by
a literary hack or "devil." The term "printer's devil" for the errand
boy in a printing office probably combines this idea with that of his
being black with ink. The common notions of the devil as black,
ill-favoured, malicious, destructive and the like, have occasioned the
application of the term to certain animals (the Tasmanian devil, the
devil-fish, the coot), to mechanical contrivances (for tearing up cloth
or separating wool), to pungent, highly seasoned dishes, broiled or
fried. In this article we are concerned with the primary sense of the
word, as used in mythology and religion.

The primitive philosophy of animism involves the ascription of all
phenomena to personal agencies. As phenomena are good or evil, produce
pleasure or pain, cause weal or woe, a distinction in the character of
these agencies is gradually recognized; the agents of good become gods,
those of evil, demons. A tendency towards the simplification and
organization of the evil as of the good forces, leads towards belief in
outstanding leaders among the forces of evil. When the divine is most
completely conceived as unity, the demonic is also so conceived; and
over against God stands Satan, or the devil.

Although it is in connexion with Hebrew and Christian monotheism that
this belief in the devil has been most fully developed, yet there are
approaches to the doctrine in other religions. In Babylonian mythology
"the old serpent goddess 'the lady Nina' was transformed into the
embodiment of all that was hostile to the powers of heaven" (Sayce's
_Hibbert Lectures_, p. 283), and was confounded with the dragon Tiamat,
"a terrible monster, reappearing in the Old Testament writings as Rahab
and Leviathan, the principle of chaos, the enemy of God and man"
(Tennant's _The Fall and Original Sin_, p. 43), and according to Gunkel
(_Schöpfung und Chaos_, p. 383) "the original of the 'old serpent' of
Rev. xii. 9." In Egyptian mythology the serpent Apap with an army of
monsters strives daily to arrest the course of the boat of the luminous
gods. While the Greek mythology described the Titans as "enchained once
for all in their dark dungeons" yet Prometheus' threat remained to
disturb the tranquillity of the Olympian Zeus. In the German mythology
the army of darkness is led by Hel, the personification of twilight,
sunk to the goddess who enchains the dead and terrifies the living, and
Loki, originally the god of fire, but afterwards "looked upon as the
father of the evil powers, who strips the goddess of earth of her
adornments, who robs Thor of his fertilizing hammer, and causes the
death of Balder the beneficent sun." In Hindu mythology the Maruts,
Indra, Agni and Vishnu wage war with the serpent Ahi to deliver the
celestial cows or spouses, the waters held captive in the caverns of the
clouds. In the _Trimurti_, Brahm[=a] (the impersonal) is manifested as
Brahm[=a] (the personal creator), Vishnu (the preserver), and Siva (the
destroyer). In Siva is perpetuated the belief in the god of Vedic times
Rudra, who is represented as "the wild hunter who storms over the earth
with his bands, and lays low with arrows the men who displease him"
(Chantepie de la Saussaye's _Religionsgeschichte_, 2nd ed., vol. ii. p.
25). The evil character of Siva is reflected in his wife, who as Kali
(the black) is the wild and cruel goddess of destruction and death. The
opposition of good and evil is most fully carried out in Zoroastrianism.
Opposed to Ormuzd, the author of all good, is Ahriman, the source of all
evil; and the opposition runs through the whole universe (D'Alviella's
_Hibbert Lectures_, pp. 158-164).

The conception of _Satan_ (Heb. [Hebrew: Satan], the adversary, Gr.
[Greek: Satanas], or [Greek: Satan], 2 Cor. xii. 7) belongs to the
post-exilic period of Hebrew development, and probably shows traces of
the influence of Persian on Jewish thought, but it has also its roots
in much older beliefs. An "evil spirit" possesses Saul (1 Sam. xvi. 14),
but it is "from the Lord." The same agency produces discord between
Abimelech and the Shechemites (Judges ix. 23). "A lying spirit in the
mouth of all his prophets" as Yahweh's messenger entices Ahab to his
doom (1 Kings xxii. 22). Growing human corruption is traced to the
fleshy union of angels and women (Gen. vi. 1-4). But generally evil,
whether as misfortune or as sin, is assigned to divine causality (1 Sam.
xviii. 10; 2 Sam. xxiv. 1; 1 Kings xxii. 20; Isa. vi. 10, lxiii. 17).
After the Exile there is a tendency to protect the divine transcendence
by the introduction of mediating angelic agency, and to separate all
evil from God by ascribing its origin to Satan, the enemy of God and
man. In the prophecy of Zechariah (iii. 1-2) he stands as the adversary
of Joshua, the high priest, and is rebuked by Yahweh for desiring that
Jerusalem should be further punished. In the book of Job he presents
himself before the Lord among the sons of God (ii. 1), yet he is
represented both as accuser and tempter. He disbelieves in Job's
integrity, and desires him to be so tried that he may fall into sin.
While, according to 2 Sam. xxiv. 1, God himself tests David in regard to
the numbering of the people, according to 1 Chron. xxi. 1 it is Satan
who tempts him.

The development of the conception continued in later Judaism, which was
probably more strongly influenced by Persian dualism. It is doubtful,
however, whether the Asmodeus (q.v.) of the book of Tobit is the same as
the A[=e]shma Da[=e]wa of the Bundahesh. He is the evil spirit who slew
the seven husbands of Sara (iii. 8), and the name probably means
"Destroyer." In the book of Enoch Satan is represented as the ruler of a
rival kingdom of evil, but here are also mentioned Satans, who are
distinguished from the fallen angels and who have a threefold function,
to tempt, to accuse and to punish. Satan possesses the ungodly
(Ecclesiasticus xxi. 27), is identified with the serpent of Gen. iii.
(Wisdom ii. 24), and is probably also represented by Asmodeus, to whom
lustful qualities are assigned (Tobit vi. 14); Gen. iii. is probably
referred to in Psalms of Solomon xvii. 49, "a serpent speaking with the
words of transgressors, words of deceit to pervert wisdom." The _Book of
the Secrets of Enoch_ not only identifies Satan with the Serpent, but
also describes his revolt against God, and expulsion from heaven. In the
Jewish _Targums_ Sammael, "the highest angel that stands before God's
throne, caused the serpent to seduce the woman"; he coalesces with
Satan, and has inferior Satans as his servants. The birth of Cain is
ascribed to a union of Satan with Eve. As accuser affecting man's
standing before God he is greatly feared.

This doctrine, stripped of much of its grossness, is reproduced in the
New Testament. Satan is the [Greek: diabolos] (Matt. xiii. 39; John
xiii. 2; Eph. iv. 27; Heb. ii. 14; Rev. ii. 10), slanderer or accuser,
the [Greek: peirazôn] (Matt. iv. 3; 1 Thess. iii. 5), the tempter, the
[Greek: ponêros] (Matt. v. 37; John xvii. 15; Eph. vi. 16), the evil
one, and the [Greek: echthros] (Matt. xiii. 39), the enemy. He is
apparently identified with Beelzebub (or Beelzebul) in Matt. xii. 26,
27. Jesus appears to recognize the existence of demons belonging to a
kingdom of evil under the leadership of Satan "the prince of demons"
(Matt. xii. 24, 26, 27), whose works in demonic possessions it is his
function to destroy (Mark i. 34, iii. 11, vi. 7; Luke x. 17-20). But he
himself conquers Satan in resisting his temptations (Matt. iv. 1-11).
Simon is warned against him, and Judas yields to him as tempter (Luke
xxii. 31; John xiii. 27). Jesus's cures are represented as a triumph
over Satan (Luke x. 18). This Jewish doctrine is found in Paul's letters
also. Satan rules over a world of evil, supernatural agencies, whose
dwelling is in the lower heavens (Eph. vi. 12): hence he is the "prince
of the power of the air" (ii. 2). He is the tempter (1 Thess. iii. 5; 1
Cor. vii. 5), the destroyer (x. 10), to whom the offender is to be
handed over for bodily destruction (v. 5), identified with the serpent
(Rom. xvi. 20; 2 Cor. xi. 3), and probably with Beliar or Belial (vi.
15); and the surrender of man to him brought death into the world (Rom.
v. 17). Paul's own "stake in the flesh" is Satan's messenger (2 Cor.
xii. 7). According to Hebrews Satan's power over death Jesus destroys by
dying (ii. 14). Revelation describes the war in heaven between God with
his angels and Satan or the dragon, the "old serpent," the deceiver of
the whole world (xii. 9), with his hosts of darkness. After the
overthrow of the Beast and the kings of the earth, Satan is imprisoned
in the bottomless pit a thousand years (xx. 2). Again loosed to deceive
the nations, he is finally cast into the lake of fire and brimstone (xx.
10; cf. Enoch liv. 5, 6; 2 Peter ii. 4). In John's Gospel and Epistles
Satan is opposed to Christ. Sinner and murderer from the beginning (1
John iii. 8) and liar by nature (John viii. 44), he enslaves men to sin
(viii. 34), causes death (verse 44), rules the present world (xiv. 30),
but has no power over Christ or those who are his (xiv. 30, xvi. 11; 1
John v. 18). He will be destroyed by Christ with all his works (John
xvi. 33; 1 John iii. 8).

In the common faith of the Gentile churches after the Apostolic Age "the
present dominion of evil demons, or of one evil demon, was just as
generally presupposed as man's need of redemption, which was regarded as
a result of that dominion. The tenacity of this belief may be explained
among other things by the living impression of the polytheism that
surrounded the communities on every side. By means of this assumption
too, humanity seemed to be unburdened, and the presupposed capacity for
redemption could, therefore, be justified in its widest range"
(Harnack's _History of Dogma_, i. p. 181). While Christ's First Advent
delivered believers from Satan's bondage, his overthrow would be
completed only by the Second Advent. The Gnostics held that "the present
world sprang from a fall of man, or from an undertaking hostile to God,
and is, therefore, the product of an evil or intermediate being" (p.
257). Some taught that while the future had been assigned by God to
Christ, the devil had received the present age (p. 309). The fathers
traced all doctrines not held by the Catholic Church to the devil, and
the virtues of heretics were regarded as an instance of the devil
transforming himself into an angel of light (ii. 91). Irenaeus ascribes
Satan's fall to "pride and arrogance and envy of God's creation"; and
traces man's deliverance from Satan to Christ's victory in resisting his
temptations; but also, guided by certain Pauline passages, represents
the death of Christ "as a ransom paid to the 'apostasy' for men who had
fallen into captivity" (ii. 290). He does not admit that Satan has any
lawful claim on man, or that God practised a deceit on him, as later
fathers taught. This theory of the _atonement_ was formulated by Origen.
"By his successful temptation the devil acquired a right over men. God
offered Christ's soul for that of men. But the devil was duped, as
Christ overcame both him and death" (p. 367). It was held by Gregory of
Nyssa, Ambrose, who uses the phrase _pia fraus_, Augustine, Leo I., and
Gregory I., who expresses it in its worst form. "The humanity of Christ
was the bait; the fish, the devil, snapped at it, and was left hanging
on the invisible hook, Christ's divinity" (iii. 307). In Athanasius the
relation of the work of Christ to Satan retires into the background,
Gregory of Nazianzus and John of Damascus felt scruples about this view.
It is expressly repudiated by Anselm and Abelard. Peter the Lombard
asserted it, disregarding these objections. Bernard represents man's
bondage to Satan "as righteously permitted as a just retribution for
sin," he being "the executioner of the divine justice." Another theory
of Origen's found less acceptance. The devil, as a being resulting from
God's will, cannot always remain a devil. The possibility of his
redemption, however, was in the 5th century branded as a heresy. Persian
dualism was brought into contact with Christian thought in the doctrine
of Mani; and it is permissible to believe that the gloomy views of
Augustine regarding man's condition are due in some measure to this
influence. Mani taught that Satan with his demons, sprung from the
kingdom of darkness, attacked the realm of light, the earth, defeated
man sent against him by the God of light, but was overthrown by the God
of light, who then delivered the primeval man (iii. 324). "During the
middle ages," says Tulloch, "the belief in the devil was
absorbing--saints conceived themselves and others to be in constant
conflict with him." This superstition, perhaps at its strongest in the
13th to the 15th century, passed into Protestantism. Luther was always
conscious of the presence and opposition of Satan. "As I found he was
about to begin again," says Luther, "I gathered together my books, and
got into bed. Another time in the night I heard him above my cell
walking on the cloister, but as I knew it was the devil I paid no
attention to him and went to sleep." He held that this world will pass
away with its pleasures, as there can be no real improvement in it, for
the devil continues in it to ply his daring and seductive devices (vii.
191). I. A. Dorner (_Christian Doctrine_, iii. p. 93) sums up Protestant
doctrine as follows:--"He is brought into relation with natural
sinfulness, and the impulse to evil thoughts and deeds is ascribed to
him. The dominion of evil over men is also represented as a slavery to
Satan, and this as punishment. He has his full power in the
extra-Christian world. But his power is broken by Christ, and by his
word victory over him is to be won. The power of creating anything is
also denied the devil, and only the power of corrupting substances is
conceded to him. But it is only at the Last Judgment that his power is
wholly annihilated; he is himself delivered up to eternal punishment."
This belief in the devil was specially strong in Scotland among both
clergy and laity in the 17th century. "The devil was always and
literally at hand," says Buckle, "he was haunting them, speaking to
them, and tempting them. Go where they would he was there."

In more recent times a great variety of opinions has been expressed on
this subject. J. S. Semler denied the reality of demonic possession, and
held that Christ in his language accommodated himself to the views of
the sick whom he was seeking to cure. Kant regarded the devil as a
personification of the radical evil in man. Daub in his _Judas
Ishcarioth_ argued that a finite evil presupposes an absolute evil, and
the absolute evil as real must be in a person. Schelling regarded the
devil as, not a person, but a real principle, a spirit let loose by the
freedom of man. Schleiermacher was an uncompromising opponent of the
common belief. "The problem remains to seek evil rather in self than in
Satan, Satan only showing the limits of our self-knowledge." Dorner has
formulated a theory which explains the development of the conception of
Satan in the Holy Scriptures as in correspondence with an evolution in
the character of Satan. "Satan appears in Scripture under four leading
characters:--first as the tempter of freedom, who desires to bring to
decision, secondly as the accuser, who by virtue of the law retorts
criminality on man; thirdly as the instrument of the Divine, which
brings evil and death upon men; fourthly and lastly he is described,
especially in the New Testament, as the enemy of God and man." He
supposes "a change in Satan in the course of the history of the divine
revelation, in conflict with which he came step by step to be a sworn
enemy of God and man, especially in the New Testament times, in which,
on the other hand, his power is broken at the root by Christ." He argues
that "the world-order, being in process as a moral order, permits
breaches everywhere into which Satan can obtain entrance" (pp. 99, 102).
H. L. Martensen gives even freer rein to speculation. "The evil
principle," he says, "has in itself no personality, but attains a
progressively universal personality in its kingdom; it has no individual
personality, save only in individual creatures, who in an especial
manner make themselves its organs; but among these is one creature in
whom the principle is so hypostasized that he has become the centre and
head of the kingdom of evil" (_Dogmatics_, p. 199). A. Ritschl gives no
place in his constructive doctrine to the belief in the devil; but
recognizes that the mutual action of individual sinners on one another
constitutes a kingdom of sin, opposed to the Kingdom of God (A. E.
Garvie, _The Ritschlian Theology_, p. 304). Kaftan affirms that a
"doctrine about Satan can as little be established as about angels, as
faith can say nothing about it, and nothing is gained by it for the
dogmatic explanation of evil. This whole province must be left to the
immediate world-view of the pious. The idea of Satan will on account of
the Scriptures not disappear from it, and it would be arrogant to wish
to set it aside. Only let everyone keep the thought that Satan also
stands under the commission of the Almighty God, and that no one must
suppose that by leading back his sins to a Satanic temptation he can get
rid of his own guilt. To transgress these limits is to assail faith"
(_Dogmatik_, p. 348). In the book entitled _Evil and Evolution_ there is
"an attempt to turn the light of modern science on to the ancient
mystery of evil." The author contends that the existence of evil is best
explained by assuming that God is confronted with Satan, who in the
process of evolution interferes with the divine designs, an interference
which the instability of such an evolving process makes not incredible.
Satan is, however, held to be a creature who has by abuse of his freedom
been estranged from, and opposed to his Creator, and who at last will be
conquered by moral means. W. M. Alexander in his book on demonic
possession maintains that "the confession of Jesus as the Messiah or Son
of God is the classical criterion of genuine demonic possession" (p.
150), and argues that, as "the Incarnation indicated the establishment
of the kingdom of heaven upon earth," there took place "a counter
movement among the powers of darkness," of which "genuine demonic
possession was one of the manifestations" (p. 249).

Interesting as these speculations are, it may be confidently affirmed
that belief in Satan is not now generally regarded as an essential
article of the Christian faith, nor is it found to be an indispensable
element of Christian experience. On the one hand science has so
explained many of the processes of outer nature and of the inner life of
man as to leave no room for Satanic agency. On the other hand the modern
view of the inspiration of the Scriptures does not necessitate the
acceptance of the doctrine of the Scriptures on this subject as finally
and absolutely authoritative. The teaching of Jesus even in this matter
may be accounted for as either an accommodation to the views of those
with whom he was dealing, or more probably as a proof of the limitation
of knowledge which was a necessary condition of the Incarnation, for it
cannot be contended that as revealer of God and redeemer of men it was
imperative that he should either correct or confirm men's beliefs in
this respect. The possibility of the existence of evil spirits,
organized under one leader Satan to tempt man and oppose God, cannot be
denied; the sufficiency of the evidence for such evil agency may,
however, be doubted; the necessity of any such belief for Christian
thought and life cannot, therefore, be affirmed. (See also DEMONOLOGY;
POSSESSION.)                                                (A. E. G.*)


DEVIZES, a market town and municipal borough in the Devizes
parliamentary division of Wiltshire, England, 86 m. W. by S. of London
by the Great Western railway. Pop. (1901) 6532. Its castle was built on
a tongue of land flanked by two deep ravines, and behind this the town
grew up in a semicircle on a stretch of bare and exposed tableland. Its
main streets, in which a few ancient timbered houses are left, radiate
from the market place, where stands a Gothic cross, the gift of Lord
Sidmouth in 1814. The Kennet and Avon Canal skirts the town on the N.,
passing over the high ground through a chain of thirty-nine locks. St
John's church, one of the most interesting in Wiltshire, is cruciform,
with a massive central tower, based upon two round and two pointed
arches. It was originally Norman of the 12th century, and the chancel
arch and low vaulted chancel, in this style, are very fine. In the
interior several ancient monuments of the Suttons and Heathcotes are
preserved, besides some beautiful carved stone work, and two rich
ceilings of oak over the chapels. St Mary's, a smaller church, is partly
Norman, but was rebuilt in the 15th and again in the 19th century. Its
lofty clerestoried nave has an elaborately carved timber roof, and the
south porch, though repaired in 1612, preserves its Norman mouldings.
The woollen industries of Devizes have lost their prosperity; but there
is a large grain trade, with engineering works, breweries, and
manufactures of silk, snuff, tobacco and agricultural implements. The
town is governed by a mayor, six aldermen and eighteen councillors.
Area, 906 acres.

Devizes (_Divisis_, _la Devise_, _De Vies_) does not appear in any
historical document prior to the reign of Henry I., when the
construction of a castle of exceptional magnificence by Roger, bishop of
Salisbury, at once constituted the town an important political centre,
and led to its speedy development. After the disgrace of Roger in 1139
the castle was seized by the Crown; in the 14th century it formed part
of the dowry of the queens of England, and figured prominently in
history until its capture and demolition by Cromwell in the Civil War of
the 17th century. Devizes became a borough by prescription, and the
first charter from Matilda, confirmed by successive later sovereigns,
merely grants exemption from certain tolls and the enjoyment of
undisturbed peace. Edward III. added a clause conferring on the town the
liberties of Marlborough, and Richard II. instituted a coroner. A gild
merchant was granted by Edward I., Edward II. and Edward III., and in
1614 was divided into the three companies of drapers, mercers and
leathersellers. The present governing charters were issued by James I.
and Charles I., the latter being little more than a confirmation of the
former, which instituted a common council consisting of a mayor, a town
clerk and thirty-six capital burgesses. These charters were surrendered
to Charles II., and a new one was conferred by James II., but abandoned
three years later in favour of the original grant. Devizes returned two
members to parliament from 1295, until deprived of one member by the
Representation of the People Act of 1867, and of the other by the
Redistribution Act of 1885. The woollen manufacture was the staple
industry of the town from the reign of Edward III. until the middle of
the 18th century, when complaints as to the decay of trade began to be
prevalent. In the reign of Elizabeth the market was held on Monday, and
there were two annual fairs at the feasts of the Purification of the
Virgin and the Decollation of John the Baptist. The market was
transferred to Thursday in the next reign, and the fairs in the 18th
century had become seven in number.

  See _Victoria County History, Wiltshire_; _History of Devizes_ (Devizes,
  1859).


DEVOLUTION, WAR OF (1667-68), the name applied to the war which arose
out of Louis XIV.'s claims to certain Spanish territories in right of
his wife Maria Theresa, upon whom the ownership was alleged to have
"devolved." (See, for the military operations, DUTCH WARS.) The war was
ended by the treaty of Aix-la-Chapelle in 1668.


DEVON, EARLS OF. From the family of De Redvers (De Ripuariis; Riviers),
who had been earls of Devon from about 1100, this title passed to Hugh
de Courtenay (c. 1275-1340), the representative of a prominent family in
the county (see Gibbon's "digression" in chap. lxi. of the _Decline and
Fall_, ed. Bury), but was subsequently forfeited by Thomas Courtenay
(1432-1462), a Lancastrian who was beheaded after the battle of Towton.
It was revived in 1485 in favour of Edward Courtenay (d. 1509), whose
son Sir William (d. 1511) married Catherine, daughter of Edward IV. Too
great proximity to the throne led to his attainder, but his son Henry
(c. 1498-1539) was restored in blood in 1517 as earl of Devon, and in
1525 was created marquess of Exeter; his second wife was a daughter of
William Blount, 4th Lord Mountjoy. The title again suffered forfeiture
on Henry's execution, but in 1553 it was recreated for his son Edward
(1526-1556). At the latter's death it became dormant in the Courtenay
family, till in 1831 a claim by a collateral branch was allowed by the
House of Lords, and the earldom of Devon was restored to the peerage,
still being held by the head of the Courtenays. The earlier earls of
Devon were referred to occasionally as earls of Devonshire, but the
former variant has prevailed, and the latter is now solely used for the
earldom and dukedom held by the Cavendishes (see DEVONSHIRE, EARLS AND
DUKES OF, and also the article COURTENAY).


DEVONIAN SYSTEM, in geology, the name applied to series of stratified
fossiliferous and igneous rocks that were formed during the Devonian
period, that is, in the interval of time between the close of the
Silurian period and the beginning of the Carboniferous; it includes the
marine Devonian and an estuarine Old Red Sandstone series of strata. The
name "Devonian" was introduced in 1829 by Sir R. Murchison and A.
Sedgwick to describe the older rocks of Cornwall and Devon which W.
Lonsdale had shown, from an examination of the fossils, to be
intermediate between the Silurian and Carboniferous. The same two
workers also carried on further researches upon the same rocks of the
continent, where already several others, F. Roemer, H. E. Beyrich, &c.,
were endeavouring to elucidate the succession of strata in this portion
of the "Transition Series." The labours of these earlier workers,
including in addition to those already mentioned, the brothers F. and G.
von Sandberger, A. Dumont, J. Gosselet, E. J. A. d'Archiac, E. P. de
Verneuil and H. von Dechen, although somewhat modified by later
students, formed the foundation upon which the modern classification of
the Devonian rocks is based.

[Illustration: Distribution of Devonian Rocks]

                   _Stratigraphy of the Devonian Facies._

  Notwithstanding the fact that it was in Devonshire and Cornwall that
  the Devonian rocks were first distinguished, it is in central Europe
  that the succession of strata is most clearly made out, and here, too,
  their geological position was first indicated by the founders of the
  system, Sedgwick and Murchison.

  _Continental Europe._--Devonian rocks occupy a large area in the
  centre of Europe, extending from the Ardennes through the south of
  Belgium across Rhenish Prussia to Darmstadt. They are best known from
  the picturesque gorges which have been cut through them by the Rhine
  below Bingen and by the Moselle below Treves. They reappear from under
  younger formations in Brittany, in the Harz and Thuringia, and are
  exposed in Franconia, Saxony, Silesia, North Moravia and eastern
  Galicia. The principal subdivisions of the system in the more typical
  areas are indicated in Table I.

  This threefold subdivision, with a central mass of calcareous strata,
  is traceable westwards through Belgium (where the Calcaire de Givet
  represents the _Stringocephalus_ limestone of the Eifel) and eastwards
  into the Harz. The rocks reappear with local petrographical
  modifications, but with a remarkable persistence of general
  palaeontological characters, in Eastern Thuringia, Franconia, Saxony,
  Silesia, the north of Moravia and East Galicia. Devonian rocks have
  been detected among the crumpled rocks of the Styrian Alps by means of
  the evidence of abundant corals, cephalopods, gasteropods,
  lamellibranchs and other organic remains. Perhaps in other tracts of
  the Alps, as well as in the Carpathian range, similar shales,
  limestones and dolomites, though as yet unfossiliferous, but
  containing ores of silver, lead, mercury, zinc, cobalt and other
  metals, may be referable to the Devonian system.

  In the centre of Europe, therefore, the Devonian rocks consist of a
  vast thickness of dark-grey sandy and shaly rocks, with occasional
  seams of limestone, and in particular with one thick central
  calcareous zone. These rocks are characterized in the lower zones by
  numerous broad-winged spirifers and by peculiar trilobites (_Phacops_,
  _Homalonotus_, &c.) which, though generically like those of the
  Silurian system, are specifically distinct. The central calcareous
  zone abounds in corals and crinoids as well as in numerous
  brachiopods. In the highest bands a profusion of coiled cephalopods
  (_Clymenia_) occurs in some of the limestones, while the shales are
  crowded with a small but characteristic ostracod crustacean
  (_Cypridina_). Here and there traces of fishes have been found, more
  especially in the Eifel, but seldom in such a state of preservation as
  to warrant their being assigned to any definite place in the
  zoological scale. Subsequently, however, E. Beyrich has described from
  Gerolstein in the Eifel an undoubted species of _Pterichthys_, which,
  as it cannot be certainly identified with any known form, he names _P.
  Rhenanus_. A _Coccosteus_ has been described by F. A. Roemer from the
  Harz, and still later one has been cited from Bicken near Herborn by
  V. Koenen; but, as Beyrich points out, there may be some doubt as to
  whether the latter is not a _Pterichthys_. A _Ctenacanthus_, seemingly
  undistinguishable from the _C. Bohemicus_ of Barrande's Étage G, has
  also been obtained from the Lower Devonian "Nereitenschichten" of
  Thuringia. The characteristic _Holoptychius nobilissimus_ has been
  detected in the Psammite de Condroz, which in Belgium forms a
  characteristic sandy portion of the Upper Devonian rocks. These are
  interesting facts, as helping to link the Devonian and Old Red
  Sandstone types together. But they are as yet too few and unsupported
  to warrant any large deduction as to the correlations between these
  types.

  It is in the north-east of Europe that the Devonian and Old Red
  Sandstone appear to be united into one system, where the limestones
  and marine organisms of the one are interstratified with the
  fish-bearing sandstones and shales of the other. In Russia, as was
  shown in the great work _Russia and the Ural Mountains_ by Murchison,
  De Verneuil and Keyserling, rocks intermediate between the Upper
  Silurian and Carboniferous Limestone formations cover an extent of
  surface larger than the British Islands. This wide development arises
  not from the thickness but from the undisturbed horizontal character
  of the strata. Like the Silurian formations described elsewhere, they
  remain to this day nearly as flat and unaltered as they were
  originally laid down. Judged by mere vertical depth, they present but
  a meagre representative of the massive Devonian greywacke and
  limestone of Germany, or of the Old Red Sandstone of Britain. Yet vast
  though the area is over which they form the surface rock, it is
  probably only a small portion of their total extent; for they are
  found turned up from under the newer formations along the flank of the
  Ural chain. It would thus seem that they spread continuously across
  the whole breadth of Russia in Europe. Though almost everywhere
  undisturbed, they afford evidence of some terrestrial oscillation
  between the time of their formation and that of the Silurian rocks on
  which they rest, for they are found gradually to overlap Upper and
  Lower Silurian formations.

                                  TABLE I.

       +-------------+-------------------+------------------------------+--------------+-----------------+-----------------+
       |             |                   |                              | Brittany and |                 |                 |
       |  Stages.    |     Ardennes.     |           Rhineland.         |   Normandy.  |    Bohemia.     |      Harz.      |
     / +-------------+-------------------+------------------------------+--------------+-----------------+-----------------+
    |  |             | Limestone of      | Cypridina slates.            | Slates of    |                 | Cypridina       |
 U  |  |             |  Etroeungt.       | Pön sandstone (Sauerland).   |  Rostellec.  |                 |  slates.        |
 P  |  | Famennien   | Psammites of      | Crumbly limestone (Kramen-   |              |                 | Clymenia        |
 P  |  | (Clymenia   |  Condroz (sandy   |  zelkalk) with Clymenia.     |              |                 |  limestone and  |
 E  |  |  beds).     |  series).         | Neheim slates in Sauerland,  |              |                 |  limestone of   |
 R  |  |             | Slates of Famenne |  and diabases, tuffs, &c.,   |              |                 |  Altenau.       |
    |  |             |  (shaly series).  |  in Dillmulde, &c.           |              |                 |                 |
 D /   +-------------+-------------------+------------------------------+--------------+-----------------+-----------------+
 E \   |             | Slates of         | Adorf limestone of Waldeck   | Limestone of |                 | Iberg limestone |
 V  |  |             |  Matagne.         |  and shales with Goniatites  |  Cop-Choux   |                 |  and Winterberg |
 O  |  | Frasnien    | Limestones, marls |  (Eifel and Aix) =           |  and green   |                 |  limestone;     |
 N  |  |(Intumesce-  |  and shale of     |  Budesheimer shales.         |  slates of   |                 |  also Adorf     |
 I  |  | cens beds). |  Frasne, and      | Marls, limestone and dolomite|  Travuliors. |                 |  limestone and  |
 A  |  |             |  red marble of    |  with Rhynchonella cuboides  |              |                 |  shales         |
 N  |  |             |  Flanders.        |  (Flinz in part).            |              |                 |  (Budesheim).   |
 .  |  |             |                   | Iberg limestone of Dillmulde.|              |                 |                 |
     \ +-------------+-------------------+------------------------------+--------------+-----------------+-----------------+
     / |             | Limestone of      | Stringocephalus limestone,   |Limestones    | H_{2} (of       | Stringocephalus |
 M  |  |             |  Givet.           |  ironstone of Brilon and     | of Chalonnes,|  Barrande) dark |  shales with    |
 I  |  |  Givérien   |                   |  Lahnmulde.                  | Montjean and |  plant-bearing  |  Flaser and     |
 D  |  |(Stringocep- |                   | Upper Lenne shales, crinoidal| l'Ecochère.  |  shales.        |  Knollenkalk.   |
 D  |  | halus beds).|                   |  limestone of Eifel, red     |              |                 | Wissenbach      |
 L  |  |             |                   |  sandstones of Aix.          |              |                 |  slates.        |
 E  |  |             |                   | Tuffs and diabases of Brilon |              | H_{1}.          |                 |
    |  |             |                   |  and Lahnmulde.              |              |                 |                 |
 D /   |             |                   | Red conglomerate of Aix.     |              |                 |                 |
 E \   +-------------+-------------------+------------------------------+--------------+-----------------+-----------------+
 V  |  |             | Calceola slates   | Calceola beds, Wissenbach    | Slates of    | G_{3} Cephalo-  | Calceola beds.  |
 O  |  |             |  and limestones   |  slates, Lower Lenne beds,   |  Porsguen,   |  pod limestone. | Nereite slates, |
 N  |  | Eifélien    |  of  Couvin.      |  Güntroder limestone and     |  greywacke   | G_{2} Tentacu-  |  slates of      |
 I  |  |  (Calceola  | Greywacke  with   |  clay slate of Lahnmulde,    |  of Fret.    |  lite limestone.|  Wieda and      |
 A  |  |   beds).    |  Spirifer         |  Dillmulde, Wildungen,       |              | G_{3} Knollen-  |  limestones of  |
 N  |  |             |  cultrijugatus.   |  Griefenstein limestone,     |              |  kalk and       |  Hasselfeld.    |
 .  |  |             |                   |  Ballersbach limestone.      |              |  mottled Mnenian|                 |
     \ |             |                   |                              |              |  limestone.     |                 |
       +-------------+-------------------+------------------------------+--------------+-----------------+-----------------+
     / | Coblentzien |Greywacke of       | Upper Coblentz slates.       | Limestones   |                 | Haupt quartzite |
 L  |  |             |  Hierges.         | Red sandstone of Eifel,      |  of Erbray,  |                 |  (of Lossen) =  |
 O  |  |             |Shales and conglom-|  Coblentz quartzite, lower   |  Brulon, Viré|                 |  Rammelsberg    |
 W  |  |             | erate of Burnot   |  Coblentz slates.            |  and Néhou,  |                 |  slates, Schal- |
 E  |  |             | with quartzite,   | Hunsrück and Siegener        |  greywacke   |                 |  lker slates =  |
 R  |  |             | of Bierlé and     |  greywacke and slates.       |  of Faou,    |                 |  Kahleberg      |
    |  |             | red  slates of    | Taunus quartzite and         |  sandstone   |                 |  sandstone.     |
 D  |  |             | Vireux, greywacke |  greywacke.                  |  of Gahard.  | F-{2} of        | Hercynian slates|
 E /   |             | of Montigny,      |                              |              |  Barrande.      |  and lime-      |
 V \   |             | sandstone of Anor.|                              |              | White Konjeprus |  stones.        |
 O  |  +-------------+-------------------+------------------------------+--------------+  Limestone with |                 |
 N  |  | Gédinnien   |Slates of St Hubert| Slates of Gédinne.           | Slates and   |  Hercynian      |                 |
 I  |  |             | and Fooz, slates  |                              |  quartzites  |  fauna.         |                 |
 A  |  |             | of Mondrepuits,   |                              |  of Plou-    |                 |                 |
 N  |  |             | arkose of Weis-   |                              |  gastel.     |                 |                 |
 .  |  |             | mes, conglomerate |                              |              |                 |                 |
    |  |             | of Fèpin.         |                              |              |                 |                 |
     \ +-------------+-------------------+------------------------------+--------------+-----------------+-----------------+

  The chief interest of the Russian rocks of this age lies in the fact,
  first signalized by Murchison and his associates, that they unite
  within themselves the characters of the Devonian and the Old Red
  Sandstone types. In some districts they consist largely of limestones,
  in others of red sandstones and marls. In the former they present
  molluscs and other marine organisms of known Devonian species; in the
  latter they afford remains of fishes, some of which are specifically
  identical with those of the Old Red Sandstone of Scotland. The
  distribution of these two palaeontological types in Russia is traced
  by Murchison to the lithological characters of the rocks, and
  consequent original diversities of physical conditions, rather than to
  differences of age. Indeed cases occur where in the same band of rock
  Devonian shells and Old Red Sandstone fishes lie commingled. In the
  belt of the formation which extends southwards from Archangel and the
  White Sea, the strata consist of sands and marls, and contain only
  fish remains. Traced through the Baltic provinces, they are found to
  pass into red and green marls, clays, thin limestones and sandstones,
  with beds of gypsum. In some of the calcareous bands such fossils
  occur as _Orthis striatula_, _Spiriferina prisca_, _Leptaena
  productoides_, _Spirifer calcaratus_, _Spirorbis omphaloides_ and
  _Orthoceras subfusiforme_. In the higher beds _Holoptychius_ and other
  well-known fishes of the Old Red Sandstone occur. Followed still
  farther to the south, as far as the watershed between Orel and
  Voronezh, the Devonian rocks lose their red colour and sandy
  character, and become thin-bedded yellow limestones, and dolomites
  with soft green and blue marls. Traces of salt deposits are indicated
  by occasional saline springs. It is evident that the geographical
  conditions of the Russian area during the Devonian period must have
  closely resembled those of the Rhine basin and central England during
  the Triassic period. The Russian Devonian rocks have been classified
  in Table II. There is an unquestionable passage of the uppermost
  Devonian rocks of Russia into the base of the Carboniferous system.

                               TABLE II.

       +---------------------------------+-----------------+------------------+-----------------------------+
       |     North-West Russia.          | Central Russia. |  Petchoraland.   |       Ural Region.          |
     / +---------------+-----------------+-----------------+------------------+-----------------------------+
 U  |  | Red sandstone | Limestones with | Limestones with | Domanik slates   | Cypridina slates, Clymenia  |
 P  |  |  (Old Red).   |  Spirifer       |  Arca oreliana. |  and limestones  |  limestones (Famennien).    |
 P <   |               |  Verneuili and  | Limestones with |  with Sp.        | Limestones with Gephyoceras |
 E  |  |               |  Sp. Archiaci.  |  Sp. Verneuili  |  Verneuili.      |  intumescens and            |
 R  |  |               |                 |  and Sp.        |                  |  Rhynchonella cuboides      |
    |  |               |                 |  Archiaci.      |                  |  (Frasnien).                |
     \ +---------------+-----------------+-----------------+------------------+-----------------------------+
 M   / |    Dolomites and limestones     |            Marl with               | Limestones and slates with  |
 I  |  |             with                |        Spirifer Anossofi           |  Sp. Anossofi (Givétien).   |
 D <   |       Spirifer Anossofi.        |           and corals.              | Limestones and slates with  |
 D  |  |                                                                      |  Pentamerus baschkiricus    |
 L  |  |                      Lower sandstone (Old Red).                      |  (Eifélien).                |
 E   \ +---------------+-----------------+-----------------+------------------+-----------------------------+
     / |                                 |                 |                  | Limestones and slates of    |
 L  |  |                                 |                 |                  |  the Yuresan and Ufa rivers,|
 O  |  |            Absent.              |                 |                  |  slate and quartzite,       |
 W <   |                                 |                 |                  |  marble of Byclaya and      |
 E  |  |                                 |                 |                  |  of Bogoslovsk, phyllitic   |
 R  |  |                                 |                 |                  |  schists and quartzite.     |
     \ +---------------+-----------------+-----------------+------------------+-----------------------------+

  The Lower Devonian of the Harz contains a fauna which is very
  different from that of the Rhenish region; to this facies the name
  "Hercynian" has been applied, and the correlation of the strata has
  been a source of prolonged discussion among continental geologists. A
  similar fauna appears in Lower Devonian of Bohemia, in Brittany
  (limestone of Erbray) and in the Urals. The Upper Devonian of the Harz
  passes up into the Culm.

  In the eastern Thuringian Fichtelgebirge the upper division is
  represented by _Clymenia_ limestone and _Cypridina_ slates with Adorf
  limestone, diabase and Planschwitzer tuff in the lower part. The
  middle division has diabases and tuffs at the top with Tentaculite and
  Nereite shales and limestones below. The upper part of the Lower
  Devonian, the sandy shale of Steinach, rests unconformably upon
  Silurian rocks. In the Carnic Alps are coral reef limestones, the
  equivalents of the Iberg limestone, which attain an enormous
  thickness; these are underlain by coral limestones with fossils
  similar to those of the Konjeprus limestone of Bohemia; below these
  are shales and nodular limestones with goniatites. The Devonian rocks
  of Poland are sandy in the lower, and more calcareous in the upper
  parts. They are of interest because while the upper portions agree
  closely with the Rhenish facies, from the top of the Coblentzien
  upwards, in the sandy beds near the base Old Red Sandstone fishes
  (_Coccosteus_, &c.) are found. In France Devonian rocks are found well
  developed in Brittany, as indicated in the table, also in Normandy and
  Maine; in the Boulonnais district only the middle and upper divisions
  are known. In south France in the neighbourhood of Cabrières, about
  Montpellier and in the Montagne Noire, all three divisions are found
  in a highly calcareous condition. Devonian rocks are recognized,
  though frequently much metamorphosed, on both the northern and
  southern flanks of the Pyrenees; while on the Spanish peninsula they
  are extensively developed. In Asturias they are no less than 3280 ft.
  thick, all three divisions and most of the central European
  subdivisions are present. In general, the Lower Devonian fossils of
  Spain bear a marked resemblance to those of Brittany.

  _Asia._--From the Ural Mountains eastward, Devonian rocks have been
  traced from point to point right across Asia. In the Altai Mountains
  they are represented by limestones of Coblentzien age with a fauna
  possessing Hercynian features. The same features are observed in the
  Devonian of the Kougnetsk basin, and in Turkestan. Well-developed
  quartzites with slates and diabases are found south of Yarkand and
  Khotan. Middle and Upper Devonian strata are widespread in China.
  Upper Devonian rocks are recorded from Persia, and from the Hindu Kush
  on the right bank of the Chitral river.

  _England._--In England the original Devonian rocks are developed in
  Devon and Cornwall and west Somerset. In north Devonshire these rocks
  consist of sandstones, grits and slates, while in south Devon there
  are, in addition, thick beds of massive limestone, and intercalations
  of lavas and tuffs. The interpretation of the stratigraphy in this
  region is a difficult matter, partly on account of the absence of good
  exposures with fossils, and partly through the disturbed condition of
  the rocks. The system has been subdivided as shown in Table III.

                                   TABLE III.

          +-----------------------------+-------------------------------+
          |    North Devon and West     |                               |
          |          Somerset.          |         South Devon.          |
          +-----------------------------+-------------------------------+
        / | Pilton group. Grits, slates | Ashburton slates.             |
   U   |  |  and thin limestones.       | Livaton slates.               |
   P   |  | Baggy group. Sandstones     | Red and green Entomis slates  |
   P  <   |  and slates.                |  (Famennien).                 |
   E   |  | Pickwell Down group.        | Red and grey slates with      |
   R   |  |  Dark slates and grits.     |  tuffs.                       |
   .   |  | Morte slates (?).           | Chudleigh goniatite limestone |
        \ |                             |  Petherwyn beds (Frasnien).   |
   M      +-----------------------------+-------------------------------+
   I    / | Ilfracombe slates with      | Torquay and Plymouth          |
   D   |  |  lenticles of limestone.    |  limestones and Ashprington   |
   D  <   | Combe Martin grits and      |  volcanic series. (Givétien   |
   L   |  |  slates.                    |  and Eifélien.)               |
   E   |  |                             | Slates and limestones of      |
   .    \ |                             |  Hope's Nose.                 |
          +-----------------------------+-------------------------------+
   L    / | Hangman grits and slates.   | Looe beds (Cornwall).         |
   O   |  | Lynton group, grits and     | Meadfoot, Cockington and      |
   W  <   |  calcareous slates.         |  Warberry series of slates    |
   E   |  | Foreland grits and slates.  |  and greywackes. (Coblentzien |
   R   |  |                             |  and Gédinnien.)              |
   .    \ +-----------------------------+-------------------------------+

  The fossil evidence clearly shows the close agreement of the Rhenish
  and south Devonshire areas. In north Devonshire the Devonian rocks
  pass upward without break into the Culm.

  _North America._--In North America the Devonian rocks are extensively
  developed; they have been studied most closely in the New York region,
  where they are classified according to Table IV.

  The classification below is not capable of application over the states
  generally and further details are required from many of the regions
  where Devonian rocks have been recognized, but everywhere the broad
  threefold division seems to obtain. In Maryland the following
  arrangement has been adopted--(1) Helderberg = Coeymans; (2) Oriskany;
  (3) Romney = Erian; (4) Jennings = Genesee and Portage; (5) Hampshire
  = Catskill in part. In the interior the Helderbergian is missing and
  the system commences with (1) Oriskany, (2) Onondaga, (3) Hamilton,
  (4) Portage (and Genesee), (5) Chemung.

  The Helderbergian series is mainly confined to the eastern part of the
  continent; there is a northern development in Maine, and in Canada
  (Gaspé, New Brunswick, Nova Scotia and Montreal); an Appalachian belt,
  and a lower Mississippian region. The series as a whole is mainly
  calcareous (2000 ft. in Gaspé), and thins out towards the west. The
  fauna has Hercynian affinities. The Oriskany formation consists
  largely of coarse sandstones; it is thin in New York, but in Maryland
  and Virginia it is several hundred feet thick. It is more widespread
  than the underlying Helderbergian. The Lower Devonian appears to be
  thick in northern Maine and in Gaspé, New Brunswick and Nova Scotia,
  but neither the palaeontology nor the stratigraphy has been completely
  worked out.

  In the Middle Devonian the thin clastic deposits at the base, Esopus
  and Schoharie grits, have not been differentiated west of the
  Appalachian region; but the Onondaga limestones are much more
  extensive. The Erian series is often described as the Hamilton series
  outside the New York district, where the _Marcellus_ shales are
  grouped together with the Hamilton shales, and numerous local
  subdivisions are included, as in Ohio, Kentucky and Tennessee. The
  rocks are mostly shales or slates, but limestones predominate in the
  western development. In Pennsylvania the Hamilton series is from 1500
  ft. to 5000 ft. thick, but in the more calcareous western extension it
  is much thinner. The _Marcellus_ shales are bituminous in places.

  The Senecan series is composed of shallow-water deposits; the Tully
  limestone, a local bed in New York, thins out in places into a layer
  of pyrites which contains a remarkable dwarfed fauna. The bituminous
  Genesee shales are thickest in Pennsylvania (300 ft.); 25 ft. on Lake
  Erie. The shales and sandstones of the Portage formation reach 1000
  ft. to 1400 ft. in western New York. In the Chautauquan series the
  Chemung formation is not always clearly separable from the Portage
  beds, it is a sandstone and conglomerate formation which reaches its
  maximum thickness (8000 ft.) in Pennsylvania, but thins rapidly
  towards the west. In the Catskill region the Upper Devonian has an Old
  Red facies--red shales and sandstones with a freshwater and brackish
  fauna.

                                     TABLE IV.

         +---------------+-------------------------------+-------------+
         |               |                               |  Probable   |
         |  Groups.      |    Formations.                |  European   |
         |               |                               | Equivalent. |
         +---------------+-------------------------------+-------------+
       / | Chautauquan.  | Chemung beds with Catskill    | Famennien.  |
  U   |  |               |  as a local facies.           |             |
  P   |  |               |                               |             |
  P  <   |             ( | Portage beds (Naples, Ithaca  | Frasnien.   |
  E   |  |             ( |  and Oneonta shales as local  |             |
  R   |  | Senecan.    < |  facies).                     |             |
  .   |  |             ( | Genesee shales.               |             |
       \ |             ( | Tully limestone.              |             |
         +---------------+-------------------------------+-------------+
  M    / | Erian.      ( | Hamilton shale.               | Givétien.   |
  I   |  |             ( | Marcellus shale.              |             |
  D   |  |               |                               |             |
  D  <   |             ( | Onondaga (Corniferous)        | Eifélien.   |
  L   |  | Ulsterian.  ( |   limestone.                  |             |
  E   |  |             < | Schoharie grit.               |             |
  .    \ |             ( | Esopus grit (Caudagalli grit).|             |
         +---------------+-------------------------------+-------------+
  L    / | Oriskanian.   | Oriskany sandstone.           | Coblentzien.|
  O   |  |               |                               |             |
  W   |  |             ( | Kingston beds.                | Gédinnien.  |
  E  <   |Helderbe-    ( | Becraft limestone.            |             |
  R   |  |   rgian.    < | New Scotland beds.            |             |
  .   |  |             ( | Coeymans limestone.           |             |
       \ +---------------+-------------------------------+-------------+

  Although the correlation of the strata has only advanced a short
  distance, there is no doubt as to the presence of undifferentiated
  Devonian rocks in many parts of the continent. In the Great Plains
  this system appears to be absent, but it is represented in Colorado,
  Utah, Nevada, Wyoming, Montana, California and Arizona; Devonian rocks
  occur between the Sierras and the Rocky Mountains, in the Arbuckle
  Mountains of Oklahoma and in Texas. In the western interior limestones
  predominate; 6000 ft. of limestone are found at Eureka, Nevada,
  beneath 2000 ft. of shale. On the Pacific coast metamorphism of the
  rocks is common, and lava-flows and tuffs occur in them.

  In Canada, besides the occurrences previously mentioned in the eastern
  region, Devonian strata are found in considerable force along the
  course of the Mackenzie river and the Canadian Rockies, whence they
  stretch out into Alaska. It is probable, however, that much that is
  now classed as Devonian in Canada will prove on fossil evidence to be
  Carboniferous.

  _South America, Africa, Australia, &c._--In South America the Devonian
  is well developed; in Argentina, Bolivia, Brazil, Peru and the
  Falkland Islands, the palaeontological horizon is about the junction
  of the Lower and Middle divisions, and the fauna has affinities with
  the Hamilton shales of North America. Nearly allied to the South
  American Devonian is that of South Africa, where they are represented
  by the Bokkeveld beds in the Cape system. In Australia we find Lower
  Devonian consisting of coarse littoral deposits with volcanic rocks;
  and a Middle division with coral limestones in Victoria, New South
  Wales and Queensland; an Upper division has also been observed. In New
  Zealand the Devonian is well exposed in the Reefton mining field; and
  it has been suggested that much of the highly metamorphosed rock may
  belong to this system.

           _Stratigraphy of the Old Red Sandstone Facies._

  The Old Red Sandstone of Britain, according to Sir Archibald Geikie,
  "consists of two subdivisions, the lower of which passes down
  conformably into the Upper Silurian deposits, the upper shading off
  in the same manner into the base of the Carboniferous system, while
  they are separated from each other by an unconformability." The Old
  Red strata appear to have been deposited in a number of elongated
  lakes or lagoons, approximately parallel to one another, with a
  general alignment in a N.E.-S.W. direction. To these areas of deposit
  Sir A. Geikie has assigned convenient distinctive names.

  In Scotland the two divisions of the system are sharply separated by a
  pronounced unconformability which is probably indicative of a
  prolonged interval of erosion. In the central valley between the base
  of the Highlands and the southern uplands lay "Lake Caledonia." Here
  the lower division is made up of some 20,000 ft. of shallow-water
  deposits, reddish-brown, yellow and grey sandstones and conglomerates,
  with occasional "cornstones," and thin limestones. The grey flagstones
  with shales are almost confined to Forfarshire, and are known as the
  "Arbroath flags." Interbedded volcanic rocks, andesites, dacites,
  diabases, with agglomerates and tuffs constitute an important feature,
  and attain a thickness of 6000 ft. in the Pentland and Ochil hills. A
  line of old volcanic vents may be traced in a direction roughly
  parallel to the trend of the great central valley. On the northern
  side of the Highlands was "Lake Orcadie," presumably much larger than
  the foregoing lake, though its boundaries are not determinable. It lay
  over Moray Firth and the east of Ross and Sutherland, and extended
  from Caithness to the Orkney Islands and S. Shetlands. It may even
  have stretched across to Norway, where similar rocks are found in
  Sognefjord and Dalsfjord, and may have had communications with some
  parts of northern Russia. Very characteristic of this area are the
  Caithness flags, dark grey and bituminous, which, with the red
  sandstones and conglomerates at their base, probably attain a
  thickness of 16,000 ft. The somewhat peculiar fauna of this series led
  Murchison to class the flags as Middle Devonian. In the Shetland
  Islands contemporaneous volcanic rocks have been observed. Over the
  west of Argyllshire lay "Lake Lorne"; here the volcanic rocks
  predominate, they are intercalated with shallow-water deposits. A
  similar set of rocks occupy the Cheviot district.

  The upper division of the Old Red Sandstone is represented in
  Shropshire and South Wales by a great series of red rocks, shales,
  sandstones and marls, some 10,000 ft. thick. They contain few fossils,
  and no break has yet been found in the series. In Scotland this series
  was deposited in basins which correspond only partially with those of
  the earlier period. They are well developed in central Scotland over
  the lowlands bordering the Moray Firth. Interbedded lavas and tuffs
  are found in the island of Hoy. An interesting feature of this series
  is the occurrence of great crowds of fossil fishes in some localities,
  notably at Dura Den in Fife. In the north of England this series rests
  unconformably upon the Lower Old Red and the Silurian.

  Flanking the Silurian high ground of Cumberland and Westmorland, and
  also in the Lammermuir hills and in Flint and Anglesey, a brecciated
  conglomerate, presenting many of the characters of a glacial deposit
  in places, has often been classed with the Old Red Sandstone, but in
  parts, at least, it is more likely to belong to the base of the
  Carboniferous system. In Ireland the lower division appears to be
  represented by the Dingle beds and Glengariff grits, while the Kerry
  rocks and the Kiltorcan beds of Cork are the equivalents of the upper
  division. Rocks of Old Red type, both lower and upper, are found in
  Spitzbergen and in Bear Island. In New Brunswick and Nova Scotia the
  Old Red facies is extensively developed. The Gaspé sandstones have
  been estimated at 7036 ft. thick. In parts of western Russia Old Red
  Sandstone fossils are found in beds intercalated with others
  containing marine fauna of the Devonian facies.

              _Devonian and Old Red Sandstone Faunas._

  The two types of sediment formed during this period--the _marine_
  Devonian and the _lagoonal_ Old Red Sandstone--representing as they do
  two different but essentially contemporaneous phases of physical
  condition, are occupied by two strikingly dissimilar faunas. Doubtless
  at all times there were regions of the earth that were marked off no
  less clearly from the normal marine conditions of which we have
  records; but this period is the earliest in which these variations of
  environment are made obvious. In some respects the faunal break
  between the older Silurian below and the younger Carboniferous above
  is not strongly marked; and in certain areas a very close relationship
  can be shown to exist between the older Devonian and the former, and
  the younger Devonian and the latter. Nevertheless, taken as a whole,
  the life of this period bears a distinct stamp of individuality.

  The two most prominent features of the Devonian seas are presented by
  corals and brachiopods. The corals were abundant individually and
  varied in form; and they are so distinctive of the period that no
  Devonian species has yet been found either in the Silurian or in the
  Carboniferous. They built reefs, as in the present day, and
  contributed to the formation of limestone masses in Devonshire, on the
  continent of Europe and in North America. Rugose and tabulate forms
  prevailed; among the former the cyathophyllids (_Cyathophyllum_) were
  important, _Phillipsastraea_, _Zaphrentis_, _Acervularia_ and the
  curious _Calceola_ (_sandalina_), an operculate genus which has given
  palaeontologists much trouble in its diagnosis, for it has been
  regarded as a pelecypod (hippurite) and a brachiopod. The tabulate
  corals were represented by _Favosites_, _Michelinia_, _Pleurodictyum_,
  _Fistulipora_, _Pachypora_ and others. _Heliolites_ and _Plasmopora_
  represent the alcyonarians. Stromatoporoids were important reef
  builders. A well-known fossil is _Receptaculites_, a genus to which it
  has been difficult to assign a definite place; it has been thought to
  be a sponge, it may be a calcareous alga, or a curious representative
  of the foraminifera.

  In the Devonian period the brachiopods reached the climax of their
  development: they compose three-quarters of the known fauna, and more
  than 1100 species have been described. Changes were taking place from
  the beginning of the period in the relative importance of genera;
  several Silurian forms dropped out, and new types were coming in. A
  noticeable feature was the development of broad-winged shells in the
  genus _Spirifer_, other spiriferids were _Ambocoelia_, _Uncites_,
  _Verneuilia_. Orthids and pentamerids were waning in importance, while
  the productids (_Productella_, _Chonetes_, _Strophalosia_) were
  increasing. The strophomenids were still flourishing, represented by
  the genera _Leptaena_, _Stropheodonta_, _Kayserella_, and others. The
  ancient _Lingula_, along with _Crania_ and _Orbiculoidea_, occur among
  the inarticulate forms. Another long-lived and wide-ranging species is
  _Atrypa reticularis_. The athyrids were very numerous (_Athyris_,
  _Retzia_, _Merista_, _Meristella_, _Kayserina_, &c.); and the
  rhynchonellids were well represented by _Pugnax_, _Hypothyris_, and
  several other genera. The important group of terebratulids appears in
  this system; amongst them _Stringocephalus_ is an eminently
  characteristic Devonian brachiopod; others are _Dielasma_,
  _Cryptonella_, _Rensselaeria_ and _Oriskania_.

  The pelecypod molluscs were represented by _Pterinea_, abundant in the
  lower members along with other large-winged forms, and by
  _Cucullella_, _Buchiola_ and _Curtonotus_ in the upper members of the
  system. Other genera are _Actinodesma_, _Cardiola_, _Nucula_,
  _Megalodon_, _Aviculopecten_, &c. Gasteropods were becoming more
  important, but the simple capulid forms prevailed: _Platyceras_
  (_Capulus_), _Straparollus_, _Pleurotomaria_, _Murchisonia_,
  _Macrocheilina_, _Euomphalus_. Among the pteropods, _Tentaculites_ was
  very abundant in some quarters; others were _Conularia_ and
  _Styliolina_. In the Devonian period the cephalopods began to make a
  distinct advance in numbers, and in development. The goniatites appear
  with the genera _Anarcestes_, _Agoniatites_, _Tornoceras_, _Bactrites_
  and others; and in the upper strata the clymenoids, forerunners of the
  later ammonoids, began to take definite shape. While several new
  nautiloids (_Homaloceras_, _Ryticeras_, &c.) made their appearance
  several of the older genera still lived on (_Orthoceras_,
  _Poterioceras_, _Actinoceras_).

  Crinoids were very abundant in some parts of the Devonian sea, though
  they were relatively scarce in others; they include the genera
  _Melocrinus_, _Haplocrinus_, _Cupressocrinus_, _Calceocrinus_ and
  _Eleuthrocrinus_. The cystideans were falling off (_Proteocystis_,
  _Tiaracrinus_), but blastoids were in the ascendant (_Nucleocrinus_,
  _Codaster_, &c.). Both brittle-stars, _Ophiura_, _Palaeophiura_,
  _Eugaster_, and true starfishes, _Palaeaster_, _Aspidosoma_, were
  present, as well as urchins (_Lepidocentrus_).

  When we turn to the crustaceans we have to deal with two distinct
  assemblages, one purely marine, trilobitic, the other mainly
  lacustrine or lagoonal with a eurypteridian facies. The trilobites had
  already begun to decline in importance, and as happens not
  infrequently with degenerating races of beasts and men, they began to
  develop strange eccentricities of ornamentation in some of their
  genera. A number of Silurian genera lived on into the Devonian period,
  and some gradually developed into new and distinctive forms; such were
  _Proëtus_, _Harpes_, _Cheirurus_, _Bronteus_ and others. Distinct
  species of _Phacops_ mark the Lower and Upper Devonian respectively,
  while the genus _Dalmania_ (_Odontochile_) was represented by species
  with an almost world-wide range. The Ostracod _Entomis_ (_Cypridina_)
  was extremely abundant in places--_Cypridinen-Schiefer_--while the
  true _Cypridina_ was also present along with _Beyrichia_,
  _Leperditia_, &c. The Phyllocarids, _Echinocaris_, _Eleuthrocaris_,
  _Tropidocaris_, are common in the United States. It is in the Old Red
  Sandstone that the eurypterids are best preserved; foremost among
  these was _Pterygotus_; _P. anglicus_ has been found in Scotland with
  a length of nearly 6 ft.; _Eurypterus_, _Slimonia_, _Stylonurus_ were
  other genera.

  Insects appear well developed, including both orthopterous and
  neuropterous forms, in the New Brunswick rocks. Mr Scudder believed he
  had obtained a specimen of Orthoptera in which a stridulating organ
  was present. A species of _Ephemera_, allied to the modern may-fly,
  had a spread of wing extending to 5 in. In the Scottish Old Red
  Sandstone myriapods, _Kampecaris_ and _Archidesmus_, have been
  described; they are somewhat simpler than more recent forms, each
  segment being separate, and supplied with only one pair of walking
  legs. Spiders and scorpions also lived upon the land.

  The great number of fish remains in the Devonian and Old Red strata,
  coupled with the truly remarkable characters possessed by some of the
  forms, has caused the period to be described as the "age of fishes."
  As in the case of the crustaceans, referred to above, we find one
  assemblage more or less peculiar to the freshwater or brackish
  conditions of the Old Red, and another characteristic of the marine
  Devonian; on the whole the former is the richer in variety, but there
  seems little doubt that quite a number of genera were capable of
  living in either environment, whatever may have been the real
  condition of the Old Red waters. Foremost in interest are the curious
  ostracoderms, a remarkable group of creatures possessing many of the
  characteristics of fishes, but more probably belonging to a distinct
  class of organisms, which appears to link the vertebrates with the
  arthropods. They had come into existence late in Silurian times; but
  it is in the Old Red strata that their remains are most fully
  preserved. They were abundant in the fresh or brackish waters of
  Scotland, England, Wales, Russia and Canada, and are represented by
  such forms as _Pteraspis_, _Cephalaspis_, _Cyathaspis_, _Tremataspis_,
  _Bothriolepis_ and _Pterichthys_.

  In the lower members of the Old Red series _Dipterus_, and in the
  upper members _Phaneropleuron_, represented the dipnoid lung-fishes;
  and it is of extreme interest to note that a few of these curious
  forms still survive in the African _Protopterus_, the Australian
  _Ceratodus_ and the South American _Lepidosiren_,--all freshwater
  fishes. Distantly related to the lung-fishes were the singular
  arthrodirans, a group possessing the unusual faculty of moving the
  head in a vertical plane. These comprise the wide-ranging _Coccosteus_
  with _Homosteus_ and _Dinichthys_, the largest fish of the period. The
  latter probably reached 20 ft. in length; it was armed with
  exceedingly powerful jaws provided with turtle-like beaks. Sharks were
  fairly prominent denizens of the sea; some were armed with cutting
  teeth, others with crushing dental plates; and although they were on
  the whole marine fishes, they were evidently able to live in fresher
  waters, like some of their modern representatives, for their remains,
  mostly teeth and large dermal spines, are found both in the Devonian
  and Old Red rocks. _Mesacanthus_, _Diplacanthus_, _Climatius_,
  _Cheiracanthus_ are characteristic genera. The crossopterygians,
  ganoids with a scaly lobe in the centre of the fins, were represented
  by _Holoptychius_ and _Glyptopomus_ in the Upper Old Red, and by such
  genera as _Diplopterus_, _Osteolepis_, _Gyroptychius_ in the lower
  division. The _Polypterus_ of the Nile and _Calamoichthys_ of South
  Africa are the modern exemplars of this group. _Cheirolepis_, found in
  the Old Red of Scotland and Canada, is the only Devonian
  representative of the actinopterygian fishes. The cyclostome fishes
  have, so far, been discovered only in Scotland, in the tiny
  _Palaeospondylus_. Amphibian remains have been found in the Devonian
  of Belgium; and footprints supposed to belong to a creature of the
  same class (_Thinopus antiquus_) have been described by Professor
  Marsh from the Chemung formation of Pennsylvania.

  _Plant Life._--In the lacustrine deposits of the Old Red Sandstone we
  find the earliest well-defined assemblage of terrestrial plants. In
  some regions so abundant are the vegetable remains that in places they
  form thin seams of veritable coal. These plants evidently flourished
  around the shores of the lakes and lagoons in which their remains were
  buried along with the other forms of life. Lycopods and ferns were the
  predominant types; and it is important to notice that both groups were
  already highly developed. The ferns include the genera _Sphenopteris_,
  _Megalopteris_, _Archaeopteris_, _Neuropteris_. Among the Lycopods are
  _Lycopodites_, _Psilophyton_, _Lepidodendron_. Modern horsetails are
  represented by _Calamocladus_, _Asterocalamites_, _Annularia_. Of
  great interest are the genera _Cordaites_, _Araucarioxylon_, &c.,
  which were synthetic types, uniting in some degree the Coniferae and
  the Cycadofilicales. With the exception of obscure markings, aquatic
  plants are not so well represented as might have been expected;
  _Parka_, a common fossil, has been regarded as a water plant with a
  creeping stem and two kinds of sporangia in sessile sporocarps.

_Physical Conditions, &c._--Perhaps the most striking fact that is
brought out by a study of the Devonian rocks and their fossils is the
gradual transgression of the sea over the land, which took place quietly
in every quarter of the globe shortly after the beginning of the period.
While in most places the Lower Devonian sediments succeed the Silurian
formations in a perfectly conformable manner, the Middle and Upper
divisions, on account of this encroachment of the sea, rest
unconformably upon the older rocks, the Lower division being
unrepresented. This is true over the greater part of South America, so
far as our limited knowledge goes, in much of the western side of North
America, in western Russia, in Thuringia and other parts of central
Europe. Of the distribution of land and sea and the position of the
coast lines in Devonian times we can state nothing with precision. The
known deposits all point to shallow waters of epicontinental seas; no
abyssal formations have been recognized. E. Kayser has pointed out the
probability of a Eurasian sea province extending through Europe towards
the east, across north and central Asia towards Manitoba in Canada, and
an American sea province embracing the United States, South America and
South Africa. At the same time there existed a great North Atlantic land
area caused partly by the uplift of the Caledonian range just before the
beginning of the period, which stretched across north Europe to eastern
Canada; on the fringe of this land the Old Red Sandstone was formed.

In the European area C. Barrois has indicated the existence of three
zones of deposition: (1) A northern, Old Red, region, including Great
Britain, Scandinavia, European Russia and Spitzbergen; here the land was
close at hand; great brackish lagoons prevailed, which communicated more
or less directly with the open sea. In European Russia, during its
general advance, the sea occasionally gained access to wide areas, only
to be driven off again, during pauses in the relative subsidence of the
land, when the continued terrigenous sedimentation once more established
the lagoonal conditions. These alternating phases were frequently
repeated. (2) A middle region, covering Devonshire and Cornwall, the
Ardennes, the northern part of the lower Rhenish mountains, and the
upper Harz to the Polish Mittelgebirge; here we find evidence of a
shallow sea, clastic deposits and a sublittoral fauna. (3) A southern
region reaching from Brittany to the south of the Rhenish mountains,
lower Harz, Thuringia and Bohemia; here was a deeper sea with a more
pelagic fauna. It must be borne in mind that the above-mentioned regions
are intended to refer to the time when the extension of the Devonian sea
was near its maximum. In the case of North America it has been shown
that in early and middle Devonian time more or less distinct faunas
invaded the continent from five different centres, viz. the Helderberg,
the Oriskany, the Onondaga, the southern Hamilton and the north-western
Hamilton; these reached the interior approximately in the order given.

Towards the close of the period, when the various local faunas had
mingled one with another and a more generalized life assemblage had been
evolved, we find many forms with a very wide range, indicating great
uniformity of conditions. Thus we find identical species of brachiopods
inhabiting the Devonian seas of England, France, Belgium, Germany,
Russia, southern Asia and China; such are, _Hypothyris_ (_Rhynchonella_)
_cuboides_, _Spirifer disjunctus_ and others. The fauna of the
_Calceola_ shales can be traced from western Europe to Armenia and
Siberia; the _Stringocephalus_ limestones are represented in Belgium,
England, the Urals and Canada; and the (_Gephyroceras_) _intumescens_
shales are found in western Europe and in Manitoba.

The Devonian period was one of comparative quietude; no violent crustal
movements seem to have taken place, and while some changes of level
occurred towards its close in Great Britain, Bohemia and Russia,
generally the passage from Devonian to Carboniferous conditions was
quite gradual. In later periods these rocks have suffered considerable
movement and metamorphism, as in the Harz, Devonshire and Cornwall, and
in the Belgian coalfields, where they have frequently been thrust over
the younger Carboniferous rocks. Volcanic activity was fairly
widespread, particularly during the middle portion of the period. In the
Old Red rocks of Scotland there is a great thickness (6000 ft.) of
igneous rocks, including diabases and andesitic lavas with agglomerates
and tuffs. In Devonshire diabases and tuffs are found in the middle
division. In west central Europe volcanic rocks are found at many
horizons, the most common rocks are diabases and diabase tuffs,
_schalstein_. Felsitic lavas and tuffs occur in the Middle Devonian of
Australia. Contemporaneous igneous rocks are generally absent in the
American Devonian, but in Nova Scotia and New Brunswick there appear to
be some.

There is little evidence as to the climate of this period, but it is
interesting to observe that local glacial conditions _may_ have existed
in places, as is suggested by the coarse conglomerate with striated
boulders in the upper Old Red of Scotland. On the other hand, the
prevalence of reef-building corals points to moderately warm
temperatures in the Middle Devonian seas.

The economic products of Devonian rocks are of some importance: in many
of the metamorphosed regions veins of tin, lead, copper, iron are
exploited, as in Cornwall, Devon, the Harz; in New Zealand, gold veins
occur. Anthracite of Devonian age is found in China and a little coal in
Germany, while the Upper Devonian is the chief source of oil and gas of
western Pennsylvania and south-western New York. In Ontario the middle
division is oil-bearing. Black phosphates are worked in central
Tennessee, and in England the marls of the "Old Red" are employed for
brick-making.

  REFERENCES.--The literature of the Devonian rocks and fossils is very
  extensive; important papers have been contributed by the following
  geologists: J. Barrande, C. Barrois, F. Béclard, E. W. Benecke, L.
  Beushausen, A. Champernowne, J. M. Clarke, Sir J. W. Dawson, A.
  Denckmann, J. S. Diller, E. Dupont, F. Frech, J. Fournet, Sir A.
  Geikie, G. Gürich, R. Hoernes, E. Kayser, C. and M. Koch, A. von
  Koenen, Hugh Miller, D. P. Oehlert, C. S. Prosser, P. de Rouville, C.
  Schuchert, T. Tschernyschew, E. O. Ulrich, W. A. E. Ussher, P. N.
  Wenjukoff, G. F. Whidborne, J. F. Whiteaves and H. S. Williams.
  Sedgwick and Murchison's original description appeared in the _Trans.
  Geol. Soc._ (2nd series, vol. v., 1839). Good general accounts will be
  found in Sir A. Geikie's _Text-Book of Geology_ (vol. ii., 4th ed.,
  1903), in E. Kayser's _Lehrbuch der Geologie_ (vol. ii., 2nd ed.,
  1902), and, for North America, in Chamberlin and Salisbury's _Geology_
  (vol. ii., 1906). See the _Index to the Geological Magazine_
  (1864-1903), and in subsequent annual volumes; _Geological Literature
  added to the Geological Society's Library_ (London), annually since
  1893; and the _Neues Jahrbuch für Min., Geologie und Paläontologie_
  (Stuttgart, 2 annual volumes). The U.S. Geological Survey publishes at
  intervals a _Bibliography and Index of North American Geology, &c._,
  and this (e.g. Bulletin 301,--the _Bibliog. and Index_ for 1901-1905)
  contains numerous references for the Devonian system in North America.
                                                              (J. A. H.)


DEVONPORT, a municipal, county and parliamentary borough of Devonshire,
England, contiguous to East Stonehouse and Plymouth, the seat of one of
the royal dockyards, and an important naval and military station. Pop.
(1901) 70,437. It is situated immediately above the N.W. angle of
Plymouth Sound, occupying a triangular peninsula formed by Stonehouse
Pool on the E. and the Hamoaze on the W. It is served by the Great
Western and the London & South Western railways. The town proper was
formerly enclosed by a line of ramparts and a ditch excavated out of the
limestone, but these are in great part demolished. Adjoining Devonport
are East Stonehouse (an urban district, pop. 15,111), Stoke and Morice
Town, the two last being suburbs of Devonport. The town hall, erected in
1821-1822 partly after the design of the Parthenon, is distinguished by
a Doric portico; while near it are the public library, in Egyptian
style, and a conspicuous Doric column built of Devonshire granite. This
monument, which is 100 ft. high, was raised in commemoration of the
naming of the town in 1824. Other institutions are the Naval Engineering
College, Keyham (1880); the municipal technical schools, opened in 1899,
the majority of the students being connected with the dockyard; the
naval barracks, Keyham (1885); the Raglan barracks and the naval and
military hospitals. On Mount Wise, which was formerly defended by a
battery (now a naval signalling station), stands the military residence,
or Government House, occupied by the commander of the Plymouth Coast
Defences; and near at hand is the principal naval residence, the naval
commander-in-chief's house. The prospect from Mount Wise over the
Hamoaze to Mount Edgecumbe on the opposite shore is one of the finest in
the south of England. The most noteworthy feature of Devonport, however,
is the royal dockyard, originally established by William III. in 1689
and until 1824 known as Plymouth Dock. It is situated within the old
town boundary and contains four docks. To this in 1853 was added Keyham
steamyard, situated higher up the Hamoaze beyond the old boundary and
connected with the Devonport yard by a tunnel. In 1896 further
extensions were begun at the Keyham yard, which became known as
Devonport North yard. Before these were begun the yard comprised two
basins, the northern one being 9 acres and the southern 7 acres in area,
and three docks, having floor-lengths of 295, 347 and 413 ft., together
with iron and brass foundries, machinery shops, engineer students' shop,
&c. The new extensions, opened by the Prince of Wales on the 21st of
February 1907, cover a total area of 118 acres lying to the northward in
front of the Naval Barracks, and involved the reclamation of 77 acres of
mudflats lying below high-water mark. The scheme presented three leading
features--a tidal basin, a group of three graving docks with entrance
lock, and a large enclosed basin with a coaling depôt at the north end.
The tidal basin, close to the old Keyham north basin, is 740 ft. long
with a mean width of 590 ft., and has an area of 10 acres, the depth
being 32 ft. at low water of spring tides. It affords access to two
graving docks, one with a floor-length of 745 ft. and 20½ ft. of water
over the sill, and the other with a length of 741 ft. and 32 ft. of
water over the sill. Each of these can be subdivided by means of an
intermediate caisson, and (when unoccupied) may serve as an entrance to
the closed basin. The lock which leads from the tidal to the closed
basin is 730 ft. long, and if necessary can be used as a dock. The
closed basin, out of which opens a third graving dock, 660 ft. long,
measures 1550 ft. by 1000 ft. and has an area of 35½ acres, with a depth
of 32 ft. at low-water springs; it has a direct entrance from the
Hamoaze, closed by a caisson. The foundations of the walls are carried
down to the rock, which in some places lies covered with mud 100 ft. or
more below coping level. Compressed air is used to work the sliding
caissons which close the entrances of the docks and closed basin. A
ropery at Devonport produces half the hempen ropes used in the navy.

By the Reform Act of 1832 Devonport was erected into a parliamentary
borough including East Stonehouse and returning two members. The ground
on which it stands is for the most part the property of the St Aubyn
family (Barons St Levan), whose steward holds a court leet and a court
baron annually. The town is governed by a mayor, sixteen aldermen and
forty-eight councillors. Area, 3044 acres.


DEVONPORT, EAST and WEST, a town of Devon county, Tasmania, situated on
both sides of the mouth of the river Mersey, 193 m. by rail N.W. of
Hobart. Pop. (1901), East Devonport, 673, West Devonport, 2101. There is
regular communication from this port to Melbourne and Sydney, and it
ranks as the third port in Tasmania. A celebrated regatta is held on the
Mersey annually on New Year's day.


DEVONSHIRE, EARLS AND DUKES OF. The Devonshire title, now in the
Cavendish family, had previously been held by Charles Blount
(1563-1606), 8th Lord Mountjoy, great-grandson of the 4th Lord Mountjoy
(d. 1534), the pupil of Erasmus; he was created earl of Devonshire in
1603 for his services in Ireland, where he became famous in subduing the
rebellion between 1600 and 1603; but the title became extinct at his
death. In the Cavendish line the 1st earl of Devonshire was William (d.
1626), second son of Sir William Cavendish (q.v.), and of Elizabeth
Hardwick, who afterwards married the 6th earl of Shrewsbury. He was
created earl of Devonshire in 1618 by James I., and was succeeded by
William, 2nd earl (1591-1628), and the latter by his son William
(1617-1684), a prominent royalist, and one of the original members of
the Royal Society, who married a daughter of the 2nd earl of Salisbury.

WILLIAM CAVENDISH, 1st duke of Devonshire (1640-1707), English
statesman, eldest son of the earl of Devonshire last mentioned, was born
on the 25th of January 1640. After completing his education he made the
tour of Europe according to the custom of young men of his rank, being
accompanied on his travels by Dr Killigrew. On his return he obtained,
in 1661, a seat in parliament for Derbyshire, and soon became
conspicuous as one of the most determined and daring opponents of the
general policy of the court. In 1678 he was one of the committee
appointed to draw up articles of impeachment against the lord treasurer
Danby. In 1679 he was re-elected for Derby, and made a privy councillor
by Charles II.; but he soon withdrew from the board with his friend Lord
Russell, when he found that the Roman Catholic interest uniformly
prevailed. He carried up to the House of Lords the articles of
impeachment against Lord Chief-Justice Scroggs, for his arbitrary and
illegal proceedings in the court of King's bench; and when the king
declared his resolution not to sign the bill for excluding the duke of
York, afterwards James II., he moved in the House of Commons that a bill
might be brought in for the association of all his majesty's Protestant
subjects. He also openly denounced the king's counsellors, and voted for
an address to remove them. He appeared in defence of Lord Russell at his
trial, at a time when it was scarcely more criminal to be an accomplice
than a witness. After the condemnation he gave the utmost possible proof
of his attachment by offering to exchange clothes with Lord Russell in
the prison, remain in his place, and so allow him to effect his escape.
In November 1684 he succeeded to the earldom on the death of his father.
He opposed arbitrary government under James II. with the same
consistency and high spirit as during the previous reign. He was
withdrawn from public life for a time, however, in consequence of a
hasty and imprudent act of which his enemies knew how to avail
themselves. Fancying that he had received an insulting look in the
presence chamber from Colonel Colepepper, a swaggerer whose attendance
at court the king encouraged, he immediately avenged the affront by
challenging the colonel, and, on the challenge being refused, striking
him with his cane. This offence was punished by a fine of £30,000, which
was an enormous sum even to one of the earl's princely fortune. Not
being able to pay he was imprisoned in the king's bench, from which he
was released only on signing a bond for the whole amount. This was
afterwards cancelled by King William. After his discharge the earl went
for a time to Chatsworth, where he occupied himself with the erection of
a new mansion, designed by William Talman, with decorations by Verrio,
Thornhill and Grinling Gibbons. The Revolution again brought him into
prominence. He was one of the seven who signed the original paper
inviting the prince of Orange from Holland, and was the first nobleman
who appeared in arms to receive him at his landing. He received the
order of the Garter on the occasion of the coronation, and was made lord
high steward of the new court. In 1690 he accompanied King William on
his visit to Holland. He was created marquis of Hartington and duke of
Devonshire in 1694 by William and Mary, on the same day on which the
head of the house of Russell was created duke of Bedford. Thus, to quote
Macaulay, "the two great houses of Russell and Cavendish, which had long
been closely connected by friendship and by marriage, by common
opinions, common sufferings and common triumphs, received on the same
day the highest honour which it is in the power of the crown to confer."
His last public service was assisting to conclude the union with
Scotland, for negotiating which he and his eldest son, the marquis of
Hartington, had been appointed among the commissioners by Queen Anne. He
died on the 18th of August 1707, and ordered the following inscription
to be put on his monument:-

                          Willielmus Dux Devon,
                   Bonorum Principum Fidelis Subditus,
                      Inimicus et Invisus Tyrannis.

He had married in 1661 the daughter of James, duke of Ormonde, and he
was succeeded by his eldest son William as 2nd duke, and by the latter's
son William as 3rd duke (viceroy of Ireland, 1737-1744). The latter's
son William (1720-1764) succeeded in 1755 as 4th duke; he married the
daughter and heiress of Richard Boyle, earl of Burlington and Cork, who
brought Lismore Castle and the Irish estates into the family; and from
November 1756 to May 1757 he was prime minister, mainly in order that
Pitt, who would not then serve under the duke of Newcastle, should be in
power. His son William (1748-1811), 5th duke, is memorable as the
husband of the beautiful Georgiana Spencer, duchess of Devonshire
(1757-1806), and of the intellectual Elizabeth Foster, duchess of
Devonshire (1758-1824), both of whom Gainsborough painted. His son
William, 6th duke (1790-1858), who died unmarried, was sent on a special
mission to the coronation of the tsar Nicholas at Moscow in 1826, and
became famous for his expenditure on that occasion; and it was he who
employed Sir Joseph Paxton at Chatsworth. The title passed in 1858 to
his cousin William (1808-1891), 2nd earl of Burlington, as 7th duke, a
man who, without playing a prominent part in public affairs, exercised
great influence, not only by his position but by his distinguished
abilities. At Cambridge in 1829 he was second wrangler, first Smith's
prizeman, and eighth classic, and subsequently he became chancellor of
the university.

SPENCER COMPTON CAVENDISH, 8th duke (1833-1908), born on the 23rd of
July 1833, was the son of the 7th duke (then earl of Burlington) and his
wife Lady Blanche Howard (sister of the earl of Carlisle). In 1854 Lord
Cavendish, as he then was, took his degree at Trinity College,
Cambridge; in 1856 he was attached to the special mission to Russia for
the new tsar's accession; and in 1857 he was returned to parliament as
Liberal member for North Lancashire. At the opening of the new
parliament of 1859 the marquis of Hartington (as he had now become)
moved the amendment to the address which overthrew the government of
Lord Derby. In 1863 he became first a lord of the admiralty, and then
under-secretary for war, and on the formation of the Russell-Gladstone
administration at the death of Lord Palmerston he entered it as war
secretary. He retired with his colleagues in July 1866; but upon Mr
Gladstone's return to power in 1868 he became postmaster-general, an
office which he exchanged in 1871 for that of secretary for Ireland.
When Mr Gladstone, after his defeat and resignation in 1874, temporarily
withdrew from the leadership of the Liberal party in January 1875, Lord
Hartington was chosen Liberal leader in the House of Commons, Lord
Granville being leader in the Lords. Mr W. E. Forster, who had taken a
much more prominent part in public life, was the only other possible
nominee, but he declined to stand. Lord Hartington's rank no doubt told
in his favour, and Mr Forster's education bill had offended the
Nonconformist members, who would probably have withheld their support.
Lord Hartington's prudent management in difficult circumstances laid his
followers under great obligations, since not only was the opposite party
in the ascendant, but his own former chief was indulging in the freedom
of independence. After the complete defeat of the Conservatives in the
general election of 1880, a large proportion of the party would have
rejoiced if Lord Hartington could have taken the Premiership instead of
Mr Gladstone, and the queen, in strict conformity with constitutional
usage (though Gladstone himself thought Lord Granville should have had
the preference), sent for him as leader of the Opposition. Mr Gladstone,
however, was clearly master of the situation: no cabinet could be formed
without him, nor could he reasonably be expected to accept a subordinate
post. Lord Hartington, therefore, gracefully abdicated the leadership,
and became secretary of state for India, from which office, in December
1882, he passed to the war office. His administration was memorable for
the expeditions of General Gordon and Lord Wolseley to Khartum, and a
considerable number of the Conservative party long held him chiefly
responsible for the "betrayal of Gordon." His lethargic manner, apart
from his position as war minister, helped to associate him in their
minds with a disaster which emphasized the fact that the government
acted "too late"; but Gladstone and Lord Granville were no less
responsible than he. In June 1885 he resigned along with his colleagues,
and in December was elected for the Rossendale Division of Lancashire,
created by the new reform bill. Immediately afterwards the great
political opportunity of Lord Hartington's life came to him in Mr
Gladstone's conversion to home rule for Ireland. Lord Hartington's
refusal to follow his leader in this course inevitably made him the
chief of the new Liberal Unionist party, composed of a large and
influential section of the old Liberals. In this capacity he moved the
first resolution at the famous public meeting at the opera house, and
also, in the House of Commons, moved the rejection of Mr Gladstone's
Bill on the second reading. During the memorable electoral contest which
followed, no election excited more interest than Lord Hartington's for
the Rossendale division, where he was returned by a majority of nearly
1500 votes. In the new parliament he held a position much resembling
that which Sir Robert Peel had occupied after his fall from power, the
leader of a small, compact party, the standing and ability of whose
members were out of all proportion to their numbers, generally esteemed
and trusted beyond any other man in the country, yet in his own opinion
forbidden to think of office. Lord Salisbury's offers to serve under him
as prime minister (both after the general election, and again when Lord
Randolph Churchill resigned) were declined, and Lord Hartington
continued to discharge the delicate duties of the leader of a middle
party with no less judgment than he had shown when leading the Liberals
during the interregnum of 1875-1880. It was not until 1895, when the
differences between Conservatives and Liberal Unionists had become
almost obliterated by changed circumstances, and the habit of acting
together, that the duke of Devonshire, as he had become by the death of
his father in 1891, consented to enter Lord Salisbury's third ministry
as president of the council. The duke thus was the nominal
representative of education in the cabinet at a time when educational
questions were rapidly becoming of great importance; and his own
technical knowledge of this difficult and intricate question being
admittedly superficial, a good deal of criticism from time to time
resulted. He had however by this time an established position in public
life, and a reputation for weight of character, which procured for him
universal respect and confidence, and exempted him from bitter attack,
even from his most determined political opponents. Wealth and rank
combined with character to place him in a measure above party; and his
succession to his father as chancellor of the university of Cambridge in
1892 indicated his eminence in the life of the country. In the same year
he had married the widow of the 7th duke of Manchester.

He continued to hold the office of lord president of the council till
the 3rd of October 1903, when he resigned on account of differences with
Mr BALFOUR (q.v.) over the latter's attitude towards free trade. As Mr
Chamberlain had retired from the cabinet, and the duke had not thought
it necessary to join Lord George Hamilton and Mr Ritchie in resigning a
fortnight earlier, the defection was unanticipated and was sharply
criticized by Mr Balfour, who, in the rearrangement of his ministry, had
only just appointed the duke's nephew and heir, Mr Victor Cavendish, to
be secretary to the treasury. But the duke had come to the conclusion
that while he himself was substantially a free-trader,[1] Mr Balfour did
not mean the same thing by the term. He necessarily became the leader of
the Free Trade Unionists who were neither Balfourites nor
Chamberlainites, and his weight was thrown into the scale against any
association of Unionism with the constructive policy of tariff reform,
which he identified with sheer Protection. A struggle at once began
within the Liberal Unionist organization between those who followed the
duke and those who followed Mr CHAMBERLAIN (q.v.); but the latter were
in the majority and a reorganization in the Liberal Unionist Association
took place, the Unionist free-traders seceding and becoming a separate
body. The duke then became president of the new organizations, the
Unionist Free Food League and the Unionist Free Trade Club. In the
subsequent developments the duke played a dignified but somewhat silent
part, and the Unionist rout in 1906 was not unaffected by his open
hostility to any taint of compromise with the tariff reform movement.
But in the autumn of 1907 his health gave way, and grave symptoms of
cardiac weakness necessitated his abstaining from public effort and
spending the winter abroad. He died, rather suddenly, at Cannes on the
24th of March 1908.

The head of an old and powerful family, a wealthy territorial magnate,
and an Englishman with thoroughly national tastes for sport, his weighty
and disinterested character made him a statesman of the first rank in
his time, in spite of the absence of showy or brilliant qualities. He
had no self-seeking ambitions, and on three occasions preferred not to
become prime minister. Though his speeches were direct and forcible, he
was not an orator, nor "clever"; and he lacked all subtlety of
intellect; but he was conspicuous for solidity of mind and
straightforwardness of action, and for conscientious application as an
administrator, whether in his public or private life. The fact that he
once yawned in the middle of a speech of his own was commonly quoted as
characteristic; but he combined a great fund of common sense and
knowledge of the average opinion with a patriotic sense of duty towards
the state. Throughout his career he remained an old-fashioned Liberal,
or rather Whig, of a type which in his later years was becoming
gradually more and more rare.

There was no issue of his marriage, and he was succeeded as 9th duke by
his nephew VICTOR CHRISTIAN CAVENDISH (b. 1868), who had been Liberal
Unionist member for West Derbyshire since 1891, and was treasurer of the
household (1900 to 1903) and financial secretary to the treasury (1903
to 1905); in 1892 he married a daughter of the marquess of Lansdowne, by
whom he had two sons.                                          (H. CH.)

[1] His own words to Mr Balfour at the time were: "I believe that
our present system of free imports is on the whole the most advantageous
to the country, though I do not contend that the principles on
which it rests possess any such authority or sanctity as to forbid any
departure from it, for sufficient reasons."


DEVONSHIRE (DEVON), a south-western county of England, bounded N.W. and
N. by the Bristol Channel, N.E. by Somerset and Dorset, S.E. and S. by
the English Channel, and W. by Cornwall. The area, 2604.9 sq. m., is
exceeded only by those of Yorkshire and Lincolnshire among the English
counties. Nearly the whole of the surface is uneven and hilly. The
county contains the highest land in England south of Derbyshire
(excepting points on the south Welsh border); and the scenery, much
varied, is in most parts striking and picturesque. The heather-clad
uplands of Exmoor, though chiefly within the borders of Somerset, extend
into North Devon, and are still the haunt of red deer, and of the small
hardy ponies called after the district. Here, as on Dartmoor, the
streams are rich in trout. Dartmoor, the principal physical feature of
the county, is a broad and lofty expanse of moorland which rises in the
southern part. Its highest point, 2039 ft., is found in the
north-western portion. Its rough wastes contrast finely with the wild
but wooded region which immediately surrounds the granite of which it is
composed, and with the rich cultivated country lying beyond. Especially
noteworthy in this fertile tract are the South Hams, a fruitful district
of apple orchards, lying between the Erme and the Dart; the rich
meadow-land around Crediton, in the vale of Exeter; and the red rocks
near Sidmouth. Two features which lend a characteristic charm to the
Devonshire landscape are the number of picturesque old cottages roofed
with thatch; and the deep lanes, sunk below the common level of the
ground, bordered by tall hedges, and overshadowed by an arch of boughs.
The north and south coasts of the county differ much in character, but
both have grand cliff and rock scenery, not surpassed by any in England
or Wales, resembling the Mediterranean seaboard in its range of colour.
As a rule the long combes or glens down which the rivers flow seaward
are densely wooded, and the country immediately inland is of great
beauty. Apart from the Tamar, which constitutes the boundary between
Devon and Cornwall, and flows into the English Channel, after forming in
its estuary the harbours of Devonport and Plymouth, the principal rivers
rise on Dartmoor. These include the Teign, Dart, Plym and Tavy, falling
into the English Channel, and the Taw flowing north towards Bideford
Bay. The river Torridge, also discharging northward, receives part of
its waters from Dartmoor through the Okement, but itself rises in the
angle of high land near Hartland point on the north coast, and makes a
wide sweep southward. The lesser Dartmoor streams are the Avon, the Erme
and the Vealm, all running south. The Exe rises on Exmoor in
Somersetshire; but the main part of its course is through Devonshire
(where it gives name to Exeter), and it is joined on its way to the
English Channel by the lesser streams of the Culm, the Creedy and the
Clyst. The Otter, rising on the Blackdown Hills, also runs south, and
the Axe, for part of its course, divides the counties of Devon and
Dorset. These eastern streams are comparatively slow; while the rivers
of Dartmoor have a shorter and more rapid course.

  _Geology._--The greatest area occupied by any one group of rocks in
  Devonshire is that covered by the Culm, a series of slates, grits and
  greywackes, with some impure limestones and occasional radiolarian
  cherts as at Codden Hill; beds of "culm," an impure variety of coal,
  are found at Bideford and elsewhere. This series of rocks occurs at
  Bampton, Exeter and Chudleigh and extends thence to the western
  boundary. North and south of the Culm an older series of slates, grits
  and limestones appears; it was considered so characteristic of the
  county that it was called the DEVONIAN SYSTEM (q.v.), the marine
  equivalent of the Old Red Sandstone of Hereford and Scotland. It lies
  in the form of a trough with its axis running east and west. In the
  central hollow the Culm reposes, while the northern and southern rims
  rise to the surface respectively north of the latitude of Barnstaple
  and South Molton and south of the latitude of Tavistock. These
  Devonian rocks have been subdivided into upper, middle and lower
  divisions, but the stratigraphy is difficult to follow as the beds
  have suffered much crumpling; fine examples of contorted strata may be
  seen almost anywhere on the north coast, and in the south, at Bolt
  Head and Start Point they have undergone severe metamorphism.
  Limestones are only poorly developed in the north, but in the south
  important masses occur, in the middle and at the base of the upper
  subdivisions, about Plymouth, Torquay, Brixham and between Newton
  Abbot and Totnes. Fossil corals abound in these limestones, which are
  largely quarried and when polished are known as Devonshire marbles.

  On the eastern side of the county is found an entirely different set
  of rocks which cover the older series and dip away from them gently
  towards the east. The lower and most westerly situated members of the
  younger rocks is a series of breccias, conglomerates, sandstones and
  marls which are probably of lower Bunter age, but by some geologists
  have been classed as Permian. These red rocks are beautifully exposed
  on the coast by Dawlish and Teignmouth, and they extend inland,
  producing a red soil, past Exeter and Tiverton. A long narrow strip of
  the same formation reaches out westward on the top of the Culm as far
  as Jacobstow. Farther east, the Bunter pebble beds are represented by
  the well-known pebble deposit of Budleigh Salterton, whence they are
  traceable inland towards Rockbeare. These are succeeded by the Keuper
  marls and sandstones, well exposed at Sidmouth, where the upper
  Greensand plateau is clearly seen to overlie them. The Greensand
  covers all the high ground northward from Sidmouth as far as the
  Blackdown Hills. At Beer Head and Axmouth the Chalk is seen, and at
  the latter place is a famous landslip on the coast, caused by the
  springs which issue from the Greensand below the Chalk. The Lower
  Chalk at Beer has been mined for building stone and was formerly in
  considerable demand. At the extreme east of the county, Rhaetic and
  Lias beds make their appearance, the former with a "bone" bed bearing
  the remains of saurians and fish.

  Dartmoor is a mass of granite that was intruded into the Culm and
  Devonian strata in post-Carboniferous times and subsequently exposed
  by denudation. Evidences of Devonian volcanic activity are abundant in
  the masses of diabase, dolerite, &c., at Bradford and Trusham, south
  of Exeter, around Plymouth and at Ashprington. Perhaps the most
  interesting is the Carboniferous volcano of Brent Tor near Tavistock.
  An Eocene deposit, the product of the denudation of the Dartmoor
  Hills, lies in a small basin at Bovey Tracey (see BOVEY BEDS); it
  yields beds of lignite and valuable clays.

  Raised beaches occur at Hope's Nose and the Thatcher Stone near
  Torquay and at other points, and a submerged forest lies in the bay
  south of the same place. The caves and fissures in the Devonian
  limestone at Kent's Hole near Torquay, Brixham and Oreston are famous
  for the remains of extinct mammals; bones of the elephant, rhinoceros,
  bear and hyaena have been found as well as flint implements of early
  man.

  _Minerals._--Silver-lead was formerly worked at Combe Martin near the
  north coast, and elsewhere. Tin has been worked on Dartmoor (in stream
  works) from an unknown period. Copper was not much worked before the
  end of the 18th century. Tin occurs in the granite of Dartmoor, and
  along its borders, but rather where the Devonian than where the
  Carboniferous rocks border the granite. It is found most plentifully
  in the district which surrounds Tavistock, which, for tin and other
  ores, is in effect the great mining district of the county. Here,
  about 4 m. from Tavistock, are the Devon Great Consols mines, which
  from 1843 to 1871 were among the richest copper mines in the world,
  and by far the largest and most profitable in the kingdom. The divided
  profits during this period amounted to £1,192,960. But the mining
  interests of Devonshire are affected by the same causes, and in the
  same way, as those of Cornwall. The quantity of ore has greatly
  diminished, and the cost of raising it from the deep mines prevents
  competition with foreign markets. In many mines tin underlies the
  general depth of the copper, and is worked when the latter has been
  exhausted. The mineral products of the Tavistock district are various,
  and besides tin and copper, ores of zinc and iron are largely
  distributed. Great quantities of refined arsenic have been produced at
  the Devon Great Consols mine, by elimination from the iron pyrites
  contained in the various lodes. Manganese occurs in the neighbourhood
  of Exeter, in the valley of the Teign and in N. Devon; but the most
  profitable mines, which are shallow, are, like those of tin and
  copper, in the Tavistock district.

  The other mineral productions of the county consist of marbles,
  building stones, slates and potters' clay. Among building stones, the
  granite of Dartmoor holds the foremost place. It is much quarried near
  Princetown, near Moreton Hampstead on the N.E. of Dartmoor and
  elsewhere. The annual export is considerable. Hard traps, which occur
  in many places, are also much used, as are the limestones of
  Buckfastleigh and of Plymouth. The Roborough stone, used from an early
  period in Devonshire churches, is found near Tavistock, and is a hard,
  porphyritic elvan, taking a fine polish. Excellent roofing slates
  occur in the Devonian series round the southern part of Dartmoor. The
  chief quarries are near Ashburton and Plymouth (Cann quarry). Potters'
  clay is worked at King's Teignton, whence it is largely exported; at
  Bovey Tracey; and at Watcombe near Torquay. The Watcombe clay is of
  the finest quality. China clay or kaolin is found on the southern side
  of Dartmoor, at Lee Moor, and near Trowlesworthy. There is a large
  deposit of umber close to Ashburton.

_Climate and Agriculture._--The climate varies greatly in different
parts of the county, but everywhere it is more humid than that of the
eastern or south-eastern parts of England. The mean annual temperature
somewhat exceeds that of the midlands, but the average summer heat is
rather less than that of the southern counties to the east. The air of
the Dartmoor highlands is sharp and bracing. Mists are frequent, and
snow often lies long. On the south coast frost is little known, and many
half hardy plants, such as hydrangeas, myrtles, geraniums and
heliotropes, live through the winter without protection. The climate of
Sidmouth, Teignmouth, Torquay and other watering places on this coast is
very equable, the mean temperature in January being 43.6° at Plymouth.
The north coast, exposed to the storms and swell of the Atlantic, is
more bracing; although there also, in the more sheltered nooks (as at
Combe Martin), myrtles of great size and age flower freely, and produce
their annual crop of berries.

Rather less than three-quarters of the total area of the county is under
cultivation; the cultivated area falling a little below the average of
the English counties. There are, however, about 160,000 acres of hill
pasture in addition to the area in permanent pasture, which is more than
one-half that of the cultivated area. The Devon breed of cattle is well
adapted both for fattening and for dairy purposes; while sheep are kept
in great numbers on the hill pastures. Devonshire is one of the chief
cattle-farming and sheep-farming counties. It is specially famous for
two products of the dairy--the clotted cream to which it gives its name,
and junket. Of the area under grain crops, oats occupy about three times
the acreage under wheat or barley. The bulk of the acreage under green
crops is occupied by turnips, swedes and mangold. Orchards occupy a
large acreage, and consist chiefly of apple-trees, nearly every farm
maintaining one for the manufacture of cider.

_Fisheries._--Though the fisheries of Devon are less valuable than those
of Cornwall, large quantities of the pilchard and herrings caught in
Cornish waters are landed at Plymouth. Much of the fishing is carried on
within the three-mile limit; and it may be asserted that trawling is the
main feature of the Devonshire industry, whereas seining and driving
characterize that of Cornwall. Pilchard, cod, sprats, brill, plaice,
soles, turbot, shrimps, lobsters, oysters and mussels are met with,
besides herring and mackerel, which are fairly plentiful. After
Plymouth, the principal fishing station is at Brixham, but there are
lesser stations in every bay and estuary.

_Other Industries._--The principal industrial works in the county are
the various Government establishments at Plymouth and Devonport. Among
other industries may be noted the lace-works at Tiverton; the
manufacture of pillow-lace for which Honiton and its neighbourhood has
long been famous; and the potteries and terra-cotta works of Bovey
Tracey and Watcombe. Woollen goods and serges are made at Buckfastleigh
and Ashburton, and boots and shoes at Crediton. Convict labour is
employed in the direction of agriculture, quarrying, &c., in the great
prison of Dartmoor.

_Communications._--The main line of the Great Western railway, entering
the county in the east from Taunton, runs to Exeter, skirts the coast as
far as Teignmouth, and continues a short distance inland by Newton Abbot
to Plymouth, after which it crosses the estuary of the Tamar by a great
bridge to Saltash in Cornwall. Branches serve Torquay and other seaside
resorts of the south coast; and among other branches are those from
Taunton to Barnstaple and from Plymouth northward to Tavistock and
Launceston. The main line of the London & South-Western railway between
Exeter and Plymouth skirts the north and west of Dartmoor by Okehampton
and Tavistock. A branch from Yeoford serves Barnstaple, Ilfracombe,
Bideford and Torrington, while the Lynton & Barnstaple and the Bideford,
Westward Ho & Appledore lines serve the districts indicated by their
names. The branch line to Princetown from the Plymouth-Tavistock line of
the Great Western company in part follows the line of a very early
railway--that constructed to connect Plymouth with the Dartmoor prison
in 1819-1825, which was worked with horse cars. The only waterways of
any importance are the Tamar, which is navigable up to Gunnislake (3 m.
S.W. of Tavistock), and the Exeter ship canal, noteworthy as one of the
oldest in England, for it was originally cut in the reign of Elizabeth.

_Population and Administration._--The area of the ancient county is
1,667,154 acres, with a population in 1891 of 631,808, and 1901 of
661,314. The area of the administrative county is 1,671,168 acres. The
county contains 33 hundreds. The municipal boroughs are Barnstaple (pop.
14,137), Bideford (8754), Dartmouth (6579), Devonport, a county borough
(70,437), Exeter, a city and county borough (47,185), Torrington,
officially Great Torrington (3241), Honiton (3271), Okehampton (2569),
Plymouth, a county borough (107,636), South Molton (2848), Tiverton
(10,382), Torquay (33,625), Totnes (4035). The other urban districts are
Ashburton (2628), Bampton (1657), Brixham (8092), Buckfastleigh (2520),
Budleigh Salterton (1883), Crediton (3974), Dawlish (4003), East
Stonehouse (15,111), Exmouth (10,485), Heavitree (7529), Holsworthy
(1371), Ilfracombe (8557), Ivybridge (1575), Kingsbridge (3025), Lynton
(1641), Newton Abbot (12,517), Northam (5355), Ottery St Mary (3495),
Paignton (8385), Salcombe (1710), Seaton (1325), Sidmouth (4201),
Tavistock (4728), Teignmouth (8636). The county is in the western
circuit, and assizes are held at Exeter. It has one court of quarter
sessions, and is divided into twenty-four petty sessional divisions. The
boroughs of Barnstaple, Bideford, Devonport, Exeter, Plymouth, South
Molton, and Tiverton have separate commissions of the peace and courts
of quarter sessions, and those of Dartmouth, Great Torrington, Torquay
and Totnes have commissions of the peace only. There are 461 civil
parishes. Devonshire is in the diocese of Exeter, with the exception of
small parts in those of Salisbury and Truro; and there are 516
ecclesiastical parishes or districts wholly or in part within the
county. The parliamentary divisions are the Eastern or Honiton,
North-eastern or Tiverton, Northern or South Molton, North-western or
Barnstaple, Western or Tavistock, Southern or Totnes, Torquay, and Mid
or Ashburton, each returning one member; and the county also contains
the parliamentary boroughs of Devonport and Plymouth, each returning two
members, and that of Exeter, returning one member.

_History._--The Saxon conquest of Devonshire must have begun some time
before the 8th century, for in 700 there existed at Exeter a famous
Saxon school. By this time, however, the Saxons had become Christians,
and established their supremacy, not by destructive inroads, but by a
gradual process of colonization, settling among the native Welsh and
allowing them to hold lands under equal laws. The final incorporation of
the district which is now Devonshire with the kingdom of Wessex must
have taken place about 766, but the county, and even Exeter, remained
partly Welsh until the time of Æthelstan. At the beginning of the 9th
century Wessex was divided into definite _pagi_, probably corresponding
to the later shires, and the Saxon Chronicle mentions Devonshire by name
in 823, when a battle was fought between the Welsh in Cornwall and the
people of Devonshire at Camelford. During the Danish invasions of the
9th century aldermen of Devon are frequently mentioned. In 851 the
invaders were defeated by the fyrd and aldermen of Devon, and in 878,
when the Danes under Hubba were harrying the coast with a squadron of
twenty-three ships, they were again defeated with great slaughter by the
fyrd. The modern hundreds of Devonshire correspond in position very
nearly with those given in the Domesday Survey, though the names have in
many cases been changed, owing generally to alterations in their places
of meeting. The hundred of Bampton formerly included estates west of the
Exe, now transferred to the hundred of Witheridge. Ten of the modern
hundreds have been formed by the union of two or more Domesday hundreds,
while the Domesday hundred of Liston has had the new hundred of
Tavistock severed from it since 1114. Many of the hundreds were
separated by tracts of waste and forest land, of which Devonshire
contained a vast extent, until in 1204 the inhabitants paid 5000 marks
to have the county disafforested, with the exception only of Dartmoor
and Exmoor.

Devonshire in the 7th century formed part of the vast bishopric of
Dorchester-on-Thames. In 705 it was attached to the newly created
diocese of Sherborne, and in 910 Archbishop Plegmund constituted
Devonshire a separate diocese, and placed the see at Crediton. About
1030 the dioceses of Devonshire and Cornwall were united, and in 1049
the see was fixed at Exeter. The archdeaconries of Exeter, Barnstaple
and Totnes are all mentioned in the 12th century and formerly comprised
twenty-four deaneries. The deaneries of Three Towns, Collumpton and
Ottery have been created since the 16th century, while those of
Tamerton, Dunkeswell, Dunsford and Plymptre have been abolished,
bringing the present number to twenty-three.

At the time of the Norman invasion Devonshire showed an active hostility
to Harold, and the easy submission which it rendered to the Conqueror
accounts for the exceptionally large number of Englishmen who are found
retaining lands after the Conquest. The many vast fiefs held by Norman
barons were known as honours, chief among them being Plympton,
Okehampton, Barnstaple, Harberton and Totnes. The honour of Plympton was
bestowed in the 12th century on the Redvers family, together with the
earldom of Devon; in the 13th century it passed to the Courtenay family,
who had already become possessed of the honour of Okehampton, and who in
1335 obtained the earldom. The dukedom of Exeter was bestowed in the
14th century on the Holland family, which became extinct in the reign of
Edward IV. The ancestors of Sir Walter Raleigh, who was born at
Budleigh, had long held considerable estates in the county.

Devonshire had an independent sheriff, the appointment being at first
hereditary, but afterwards held for one year only. In 1320 complaint was
made that all the hundreds of Devonshire were in the hands of the great
lords, who did not appoint a sufficiency of bailiffs for their proper
government. The miners of Devon had independent courts, known as
stannary courts, for the regulation of mining affairs, the four stannary
towns being Tavistock, Ashburton, Chagford, and Plympton. The ancient
miners' parliament was held in the open air at Crockern's Tor.

The castles of Exeter and Plympton were held against Stephen by Baldwin
de Redvers, and in the 14th and 15th centuries the French made frequent
attacks on the Devonshire coast, being repulsed in 1404 by the people of
Dartmouth. In the Wars of the Roses the county was much divided, and
frequent skirmishes took place between the earl of Devon and Lord
Bonville, the respective champions of the Lancastrian and Yorkist
parties. Great disturbances in the county followed the Reformation of
the 16th century and in 1549 a priest was compelled to say mass at
Sampford Courtney. On the outbreak of the Civil War the county as a
whole favoured the parliament, but the prevailing desire was for peace,
and in 1643 a treaty for the cessation of hostilities in Devonshire and
Cornwall was agreed upon. Skirmishes, however, continued until the
capture of Dartmouth and Exeter in 1646 put an end to the struggle. In
1688 the prince of Orange landed at Torbay and was entertained for
several days at Ford and at Exeter.

The tin mines of Devon have been worked from time immemorial, and in the
14th century mines of tin, copper, lead, gold and silver are mentioned.
Agriculturally the county was always poor, and before the
disafforestation rendered especially so through the ravages committed by
the herds of wild deer. At the time of the Domesday Survey the salt
industry was important, and there were ninety-nine mills in the county
and thirteen fisheries. From an early period the chief manufacture was
that of woollen cloth, and a statute 4 Ed. IV. permitted the manufacture
of cloths of a distinct make in certain parts of Devonshire. About 1505
Anthony Bonvis, an Italian, introduced an improved method of spinning
into the county, and cider-making is mentioned in the 16th century. In
1680 the lace industry was already flourishing at Colyton and Ottery St
Mary, and flax, hemp and malt were largely produced in the 17th and 18th
centuries.

Devonshire returned two members to parliament in 1290, and in 1295
Barnstaple, Exeter, Plympton, Tavistock, Torrington and Totnes were also
represented. In 1831 the county with its boroughs returned a total of
twenty-six members, but under the Reform Act of 1832 it returned four
members in two divisions, and with ten boroughs was represented by a
total of eighteen members. Under the act of 1868 the county returned six
members in three divisions, and four of the boroughs were disfranchised,
making a total of seventeen members.

_Antiquities._--In primeval antiquities Devonshire is not so rich as
Cornwall; but Dartmoor abounds in remains of the highest interest, the
most peculiar of which are the long parallel alignments of upright
stones, which, on a small scale, resemble those of Carnac in Brittany.
On Dartmoor the lines are invariably straight, and are found in direct
connexion with cairns, and with circles which are probably sepulchral.
These stone avenues are very numerous. Of the so-called sacred circles
the best examples are the "Longstones" on Scorhill Down, and the "Grey
Wethers" under Sittaford Tor. By far the finest cromlech is the
"Spinster's Rock" at Drewsteignton, a three-pillared cromlech which may
well be compared with those of Cornwall. There are numerous menhirs or
single upright stones; a large dolmen or holed stone lies in the bed of
the Teign, near the Scorhill circle; and rock basins occur on the summit
of nearly every tor on Dartmoor (the largest are on Kestor, and on
Heltor, above the Teign). It is, however, tolerably evident that these
have been produced by the gradual disintegration of the granite, and
that the dolmen in the Teign is due to the action of the river. Clusters
of hut foundations, circular, and formed of rude granite blocks, are
frequent; the best example of such a primitive village is at Batworthy,
near Chagford; the type resembles that of East Cornwall. Walled
enclosures, or pounds, occur in many places; Grimspound is the most
remarkable. Boundary lines, also called trackways, run across Dartmoor
in many directions; and the rude bridges, formed of great slabs of
granite, deserve notice. All these remains are on Dartmoor. Scattered
over the county are numerous large hill castles and camps,--all
earthworks, and all apparently of the British period. Roman relics have
been found from time to time at Exeter (_Isca Damnoniorum_), the only
large Roman station in the county.

The churches are for the most part of the Perpendicular period, dating
from the middle of the 14th to the end of the 15th century. Exeter
cathedral is of course an exception, the whole (except the Norman
towers) being very beautiful Decorated work. The special features of
Devonshire churches, however, are the richly carved pulpits and chancel
screens of wood, in which this county exceeded every other in England,
with the exception of Norfolk and Suffolk. The designs are rich and
varied, and the skill displayed often very great. Granite crosses are
frequent, the finest and earliest being that of Coplestone, near
Crediton. Monastic remains are scanty; the principal are those at Tor,
Buckfast, Tavistock and Buckland Abbeys. Among domestic buildings the
houses of Wear Gilford, Bradley and Dartington of the 15th century;
Bradfield and Holcombe Rogus (Elizabethan), and Forde (Jacobean),
deserve notice. The ruined castles of Okehampton (Edward I.), Exeter,
with its vast British earthworks, Berry Pomeroy (Henry III., with ruins
of a large Tudor mansion), Totnes (Henry III.) and Compton (early 15th
century), are all interesting and picturesque.

  AUTHORITIES.--T. Westcote, _Survey of Devon_, written about 1630, and
  first printed in 1845; J. Prince, _Worthies of Devon_ (Exeter, 1701);
  Sir W. Pole, _Collections towards a History of the County of Devon_
  (London, 1791); R. Polwhele, _History of Devonshire_ (3 vols. Exeter,
  1797, 1798-1800); T. Moore, _History of Devon from the Earliest Period
  to the Present Time_ (vols, i., ii., London, 1829-1831); G. Oliver,
  _Historic Collections relating to the Monasteries in Devon_ (Exeter,
  1820); D. and S. Lysons, _Magna Britannia_ (vol. vi., London, 1822);
  _Ecclesiastical Antiquities in Devon_ (Exeter, 1844); Mrs Bray,
  _Traditions of Devonshire_, in a series of letters to Robert Southey
  (London, 1838); G. C. Boase, _Devonshire Bibliography_ (London, 1883);
  Sir W. R. Drake, _Devonshire Notes and Notelets_ (London, 1888); S.
  Hewett, _Peasant Speech of Devon_ (London, 1892); R. N. Worth,
  _History of Devonshire_ (London, 1886, new edition, 1895); C. Worthy,
  _Devonshire Parishes_ (Exeter, 1887); _Devonshire Wills_ (London,
  1896); _Victoria County History, Devonshire_.


DEVRIENT, the name of a family of German actors.

LUDWIG DEVRIENT (1784-1832), born in Berlin on the 15th of December
1784, was the son of a silk merchant. He was apprenticed to an
upholsterer, but, suddenly leaving his employment, joined a travelling
theatrical company, and made his first appearance on the stage at Gera
in 1804 as the messenger in Schiller's _Braut von Messina_. By the
interest of Count Brühl, he appeared at Rudolstadt as Franz Moor in
Schiller's _Räuber_, so successfully that he obtained a permanent
engagement at the ducal theatre in Dessau, where he played until 1809.
He then received a call to Breslau, where he remained for six years. So
brilliant was his success in the title-parts of several of Shakespeare's
plays, that Iffland began to fear for his own reputation; yet that great
artist was generous enough to recommend the young actor as his only
possible successor. On Iffland's death Devrient was summoned to Berlin,
where he was for fifteen years the popular idol. He died there on the
30th of December 1832. Ludwig Devrient was equally great in comedy and
tragedy. Falstaff, Franz Moor, Shylock, King Lear and Richard II. were
among his best parts. Karl von Holtei in his _Reminiscences_ has given a
graphic picture of him and the "demoniac fascination" of his acting.

  See Z. Funck, _Aus dem Leben zweier Schauspieler, Ifflands und
  Devrients_ (Leipzig, 1838); H. Smidt in _Devrient-Novellen_ (3rd ed.,
  Berlin, 1882); R. Springer in the novel _Devrient und Hoffmann_
  (Berlin, 1873), and Eduard Devrient's _Geschichte der deutschen
  Schauspielkunst_ (Leipzig, 1861).

Three of the nephews of Ludwig Devrient, sons of his brother, a
merchant, were also connected with the stage. KARL AUGUST DEVRIENT
(1797-1872) was born at Berlin on the 5th of April 1797. After being for
a short time in business, he entered a cavalry regiment as volunteer and
fought at Waterloo. He then joined the stage, making his first
appearance on the stage in 1819 at Brunswick. In 1821 he received an
engagement at the court theatre in Dresden, where, in 1823, he married
Wilhelmine Schröder (see SCHRÖDER-DEVRIENT). In 1835 he joined the
company at Karlsruhe, and in 1839 that at Hanover. His best parts were
Wallenstein and King Lear. He died on the 5th of April 1872. His brother
PHILIPP EDUARD DEVRIENT (1801-1877), born at Berlin on the 11th of
August 1801, was for a time an opera singer. Turning his attention to
theatrical management, he was from 1844 to 1846 director of the court
theatre in Dresden. Appointed to Karlsruhe in 1852, he began a thorough
reorganization of the theatre, and in the course of seventeen years of
assiduous labour, not only raised it to a high position, but enriched
its repertory by many noteworthy librettos, among which _Die Gunst des
Augenblicks_ and _Verirrungen_ are the best known. But his chief work is
his history of the German stage--_Geschichte der deutschen
Schauspielkunst_ (Leipzig, 1848-1874). He died on the 4th of October
1877. A complete edition of his works--_Dramatische und dramaturgische
Schriften_--was published in ten volumes (Leipzig, 1846-1873).

The youngest and the most famous of the three nephews of Ludwig Devrient
was GUSTAV EMIL DEVRIENT (1803-1872), born in Berlin on the 4th of
September 1803. He made his first appearance on the stage in 1821, at
Brunswick, as Raoul in Schiller's _Jungfrau von Orleans_. After a short
engagement in Leipzig, he received in 1829 a call to Hamburg, but after
two years accepted a permanent appointment at the court theatre in
Dresden, to which he belonged until his retirement in 1868. His chief
characters were Hamlet, Uriel Acosta (in Karl Gutzkow's play), Marquis
Posa (in Schiller's _Don Carlos_), and Goethe's Torquato Tasso. He acted
several times in London, where his Hamlet was considered finer than
Kemble's or Edmund Kean's. He died on the 7th of August 1872.

OTTO DEVRIENT (1838-1894), another actor, born in Berlin on the 3rd of
October 1838, was the son of Philipp Eduard Devrient. He joined the
stage in 1856 at Karlsruhe, and acted successively in Stuttgart, Berlin
and Leipzig, until he received a fixed appointment at Karlsruhe, in
1863. In 1873 he became stage manager at Weimar, where he gained great
praise for his _mise en scène_ of Goethe's _Faust_. After being manager
of the theatres in Mannheim and Frankfort he retired to Jena, where in
1883 he was given the honorary degree of doctor of philosophy. In 1884
he was appointed director of the court theatre in Oldenburg, and in
1889 director of dramatic plays in Berlin. He died at Stettin on the
23rd of June 1894.


DEW. The word "dew" (O.E. _deaw_; cf. Ger. _Tau_) is a very ancient one
and its meaning must therefore be defined on historical principles.
According to the _New English Dictionary_, it means "the moisture
deposited in minute drops upon any cool surface by condensation of the
vapour of the atmosphere; formed after a hot day, during or towards
night and plentiful in the early morning." Huxley in his _Physiography_
makes the addition "without production of mist." The formation of mist
is not necessary for the formation of dew, nor does it necessarily
prevent it. If the deposit of moisture is in the form of ice instead of
water it is called hoarfrost. The researches of Aitken suggest that the
words "by condensation of the vapour in the atmosphere" might be omitted
from the definition. He has given reasons for believing that the large
dewdrops on the leaves of plants, the most characteristic of all the
phenomena of dew, are to be accounted for, in large measure at least, by
the exuding of drops of water from the plant through the pores of the
leaves themselves. The formation of dewdrops in such cases is the
continuation of the irrigation process of the plant for supplying the
leaves with water from the soil. The process is set up in full vigour in
the daytime to maintain tolerable thermal conditions at the surface of
the leaf in the hot sun, and continued after the sun has gone.

On the other hand, the most typical physical experiment illustrating the
formation of dew is the production of a deposit of moisture, in minute
drops, upon the exterior surface of a glass or polished metal vessel by
the cooling of a liquid contained in the vessel. If the liquid is water,
it can be cooled by pieces of ice; if volatile like ether, by bubbling
air through it. No deposit is formed by this process until the
temperature is reduced to a point which, from that circumstance, has
received a special name, although it depends upon the state of the air
round the vessel. So generally accepted is the physical analogy between
the natural formation of dew and its artificial production in the manner
described, that the point below which the temperature of a surface must
be reduced in order to obtain the deposit is known as the "dew-point."

In the view of physicists the dew-point is the temperature at which, _by
being cooled without change of pressure_, the air becomes saturated with
water vapour, not on account of any increase of supply of that compound,
but by the diminution of the capacity of the air for holding it in the
gaseous condition. Thus, when the dew-point temperature has been
determined, the pressure of water vapour in the atmosphere at the time
of the deposit is given by reference to a table of saturation pressures
of water vapour at different temperatures. As it is a well-established
proposition that the pressure of the water vapour in the air does not
vary while the air is being cooled without change of its total external
pressure, the saturation pressure at the dew-point gives the pressure of
water vapour in the air when the cooling commenced. Thus the artificial
formation of dew and consequent determination of the dew-point is a
recognized method of measuring the pressure, and thence the amount of
water vapour in the atmosphere. The dew-point method is indeed in some
ways a fundamental method of hygrometry.

The dew-point is a matter of really vital consequence in the question of
the oppressiveness of the atmosphere or its reverse. So long as the
dew-point is low, high temperature does not matter, but when the
dew-point begins to approach the normal temperature of the human body
the atmosphere becomes insupportable.

The physical explanation of the formation of dew consists practically in
determining the process or processes by which leaves, blades of grass,
stones, and other objects in the open air upon which dew may be
observed, become cooled "below the dew-point."

Formerly, from the time of Aristotle at least, dew was supposed to
"fall." That view of the process was not extinct at the time of
Wordsworth and poets might even now use the figure without reproach. To
Dr Charles Wells of London belongs the credit of bringing to a focus the
ideas which originated with the study of radiation at the beginning of
the 19th century, and which are expressed by saying that the cooling
necessary to produce dew on exposed surfaces is to be attributed to the
radiation from the surfaces to a clear sky. He gave an account of the
theory of automatic cooling by radiation, which has found a place in all
text-books of physics, in his first _Essay on Dew_ published in 1818.
The theory is supported in that and in a second essay by a number of
well-planned observations, and the essays are indeed models of
scientific method. The process of the formation of dew as represented by
Wells is a simple one. It starts from the point of view that all bodies
are constantly radiating heat, and cool automatically unless they
receive a corresponding amount of heat from other bodies by radiation or
conduction. Good radiators, which are at the same time bad conductors of
heat, such as blades of grass, lose heat rapidly on a clear night by
radiation to the sky and become cooled below the dew-point of the
atmosphere.

The question was very fully studied by Melloni and others, but little
more was added to the explanation given by Wells until 1885, when John
Aitken of Falkirk called attention to the question whether the water of
dewdrops on plants or stones came from the air or the earth, and
described a number of experiments to show that under the conditions of
observation in Scotland, it was the earth from which the moisture was
probably obtained, either by the operation of the vascular system of
plants in the formation of exuded dewdrops, or by evaporation and
subsequent condensation in the lowest layer of the atmosphere. Some
controversy was excited by the publication of Aitken's views, and it is
interesting to revert to it because it illustrates a proposition which
is of general application in meteorological questions, namely, that the
physical processes operative in the evolution of meteorological
phenomena are generally complex. It is not radiation alone that is
necessary to produce dew, nor even radiation from a body which does not
conduct heat. The body must be surrounded by an atmosphere so fully
supplied with moisture that the dew-point can be passed by the cooling
due to radiation. Thus the conditions favourable for the formation of
dew are (1) a good radiating surface, (2) a still atmosphere, (3) a
clear sky, (4) thermal insulation of the radiating surface, (5) warm
moist ground or some other provision to produce a supply of moisture in
the surface layers of air.

Aitken's contribution to the theory of dew shows that in considering the
supply of moisture we must take into consideration the ground as well as
the air and concern ourselves with the temperature of both. Of the five
conditions mentioned, the first four may be considered necessary, but
the fifth is very important for securing a copious deposit. It can
hardly be maintained that no dew could form unless there were a supply
of water by evaporation from warm ground, but, when such a supply is
forthcoming, it is evident that in place of the limited process of
condensation which deprives the air of its moisture and is therefore
soon terminable, we have the process of distillation which goes on as
long as conditions are maintained. This distinction is of some practical
importance for it indicates the protecting power of wet soil in favour
of young plants as against night frost. If distillation between the
ground and the leaves is set up, the temperature of the leaves cannot
fall much below the original dew-point because the supply of water for
condensation is kept up; but if the compensation for loss of heat by
radiation is dependent simply on the condensation of water from the
atmosphere, without renewal of the supply, the dew-point will gradually
get lower as the moisture is deposited and the process of cooling will
go on.

In these questions we have to deal with comparatively large changes
taking place within a small range of level. It is with the layer a few
inches thick on either side of the surface that we are principally
concerned, and for an adequate comprehension of the conditions close
consideration is required. To illustrate this point reference may be
made to figs. 1 and 2, which represent the condition of affairs at 10.40
P.M. on about the 20th of October 1885, according to observations by
Aitken. Vertical distances represent heights in feet, while the
temperatures of the air and the dew-point are represented by horizontal
distances and their variations with height by the curved lines of the
diagram. The line marked 0 is the ground level itself, a rather
indefinite quantity when the surface is grass. The whole vertical
distance represented is from 4 ft. above ground to 1 ft. below ground,
and the special phenomena which we are considering take place in the
layer which represents the rapid transition between the temperature of
the ground 3 in. below the surface and that of the air a few inches
above ground.

[Illustration: FIG. 1.]

[Illustration: FIG. 2.]

The point of interest is to determine where the dew-point curve and
dry-bulb curve will cut. If they cut above the surface, mist will
result; if they cut at the surface, dew will be formed. Below the
surface, it may be assumed that the air is saturated with moisture and
any difference in temperature of the dew-point is accompanied by
distillation. It may be remarked, by the way, that such distillation
between soil layers of different temperatures must be productive of the
transference of large quantities of water between different levels in
the soil either upward or downward according to the time of year.

These diagrams illustrate the importance of the warmth and moisture of
the ground in the phenomena which have been considered. From the surface
there is a continual loss of heat going on by radiation and a continual
supply of warmth and moisture from below. But while the heat can escape,
the moisture cannot. Thus the dry-bulb line is deflected to the left as
it approaches the surface, the dew-point line to the right. Thus the
effect of the moisture of the ground is to cause the lines to approach.
In the case of grass, fig. 2, the deviation of the dry-bulb line to the
left to form a sharp minimum of temperature at the surface is well
shown. The dew-point line is also shown diverted to the left to the same
point as the dry-bulb; but that could only happen if there were so
copious a condensation from the atmosphere as actually to make the air
drier at the surface than up above. In diagram 1, for soil, the effect
on air temperature and moisture is shown; the two lines converge to cut
at the surface where a dew deposit will be formed. Along the underground
line there must be a gradual creeping of heat and moisture towards the
surface by distillation, the more rapid the greater the temperature
gradient.

The amount of dew deposited is considerable, and, in tropical countries,
is sometimes sufficiently heavy to be collected by gutters and spouts,
but it is not generally regarded as a large percentage of the total
rainfall. Loesche estimates the amount of dew for a single night on the
Loango coast at 3 mm., but the estimate seems a high one. Measurements
go to show that the depth of water corresponding with the aggregate
annual deposit of dew is 1 in. to 1.5 in. near London (G. Dines), 1.2
in. at Munich (Wollny), 0.3 in. at Montpellier (Crova), 1.6 in. at
Tenbury, Worcestershire (Badgley).

With the question of the amount of water collected as dew, that of the
maintenance of "dew ponds" is intimately associated. The name is given
to certain isolated ponds on the upper levels of the chalk downs of the
south of England and elsewhere. Some of these ponds are very ancient, as
the title of a work on _Neolithic Dewponds_ by A. J. and G. Hubbard
indicates. Their name seems to imply the hypothesis that they depend
upon dew and not entirely upon rain for their maintenance as a source of
water supply for cattle, for which they are used. The question has been
discussed a good deal, but not settled; the balance of evidence seems to
be against the view that dew deposits make any important contribution to
the supply of water. The construction of dew ponds is, however, still
practised on traditional lines, and it is said that a new dew pond has
first to be filled artificially. It does not come into existence by the
gradual accumulation of water in an impervious basin.

  AUTHORITIES.--For _Dew_, see the two essays by Dr Charles Wells
  (London, 1818), also "An Essay on Dew," edited by Casella (London,
  1866), Longmans', with additions by Strachan; Melloni, _Pogg. Ann._
  lxxi. pp. 416, 424 and lxxiii. p. 467; Jamin, "Compléments à la
  théorie de la rosée," _Journal de physique_, viii. p. 41; J. Aitken,
  on "Dew," _Trans. Roy. Soc. of Edinburgh_, xxxiii., part i. 2, and
  "Nature," vol. xxxiii. p. 256; C. Tomlinson, "Remarks on a new Theory
  of Dew," _Phil. Mag._ (1886), 5th series, vol. 21, p. 483 and vol. 22,
  p. 270; Russell, _Nature_, vol 47, p. 210; also _Met. Zeit._ (1893),
  p. 390; Homén, _Bodenphysikalische und meteorologische Beobachtungen_
  (Berlin, 1894), iii.; _Taubildung_, p. 88, &c.; Rubenson, "Die
  Temperatur-und Feuchtigkeitsverhältnisse in den unteren Luftschichten
  bei der Taubildung," _Met. Zeit._ xi. (1876), p. 65; H. E. Hamberg,
  "Température et humidité de l'air à différentes hauteurs à Upsal,"
  _Soc. R. des sciences d'Upsal_ (1876); review in _Met. Zeit._ xii.
  (1877), p. 105.

  For _Dew Ponds_, see Stephen Hales, _Statical Essays_, vol. i.,
  experiment xix., pp. 52-57 (2nd ed., London, 1731); Gilbert White,
  _Natural History and Antiquities of Selborne_, letter xxix. (London,
  1789); Dr C. Wells, _An Essay on Dew_ (London, 1818, 1821 and 1866);
  Rev. J. C. Clutterbuck, "Prize Essay on Water Supply," _Journ. Roy.
  Agric. Soc._, 2nd series, vol. i. pp. 271-287 (1865); Field and
  Symons, "Evaporation from the Surface of Water," _Brit. Assoc. Rep._
  (1869), sect., pp. 25, 26; J. Lucas, "Hydrogeology: One of the
  Developments of Modern Practical Geology," _Trans. Inst. Surveyors_,
  vol. ix. pp. 153-232 (1877); H. P. Slade, "A Short Practical Treatise
  on Dew Ponds" (London, 1877); Clement Reid, "The Natural History of
  Isolated Ponds," _Trans. Norfolk and Norwich Naturalists' Society_,
  vol. v. pp. 272-286 (1892); Professor G. S. Brady, _On the Nature and
  Origin of Freshwater Faunas_ (1899); Professor L. C. Miall, "Dew
  Ponds," _Reports of the British Association_ (Bradford Meeting, 1900),
  pp. 579-585; A. J. and G. Hubbard, "Neolithic Dewponds and
  Cattle-Ways" (London, 1904, 1907).                         (W. N. S.)


DEWAN or DIWAN, an Oriental term for finance minister. The word is
derived from the Arabian _diwan_, and is commonly used in India to
denote a minister of the Mogul government, or in modern days the prime
minister of a native state. It was in the former sense that the grant of
the _dewanny_ to the East India Company in 1765 became the foundation of
the British empire in India.


DEWAR, SIR JAMES (1842- ), British chemist and physicist, was born at
Kincardine-on-Forth, Scotland, on the 20th of September 1842. He was
educated at Dollar Academy and Edinburgh University, being at the latter
first a pupil, and afterwards the assistant, of Lord Playfair, then
professor of chemistry; he also studied under Kekulé at Ghent. In 1875
he was elected Jacksonian professor of natural experimental philosophy
at Cambridge, becoming a fellow of Peterhouse, and in 1877 he succeeded
Dr J. H. Gladstone as Fullerian professor of chemistry in the Royal
Institution, London. He was president of the Chemical Society in 1897,
and of the British Association in 1902, served on the Balfour Commission
on London Water Supply (1893-1894), and as a member of the Committee on
Explosives (1888-1891) invented cordite jointly with Sir Frederick Abel.
His scientific work covers a wide field. Of his earlier papers, some
deal with questions of organic chemistry, others with Graham's
hydrogenium and its physical constants, others with high temperatures,
e.g. the temperature of the sun and of the electric spark, others again
with electro-photometry and the chemistry of the electric arc. With
Professor J. G. M'Kendrick, of Glasgow, he investigated the
physiological action of light, and examined the changes which take place
in the electrical condition of the retina under its influence. With
Professor G. D. Liveing, one of his colleagues at Cambridge, he began in
1878 a long series of spectroscopic observations, the later of which
were devoted to the spectroscopic examination of various gaseous
constituents separated from atmospheric air by the aid of low
temperatures; and he was joined by Professor J. A. Fleming, of
University College, London, in the investigation of the electrical
behaviour of substances cooled to very low temperatures. His name is
most widely known in connexion with his work on the liquefaction of the
so-called permanent gases and his researches at temperatures approaching
the zero of absolute temperature. His interest in this branch of inquiry
dates back at least as far as 1874, when he discussed the "Latent Heat
of Liquid Gases" before the British Association. In 1878 he devoted a
Friday evening lecture at the Royal Institution to the then recent work
of L. P. Cailletet and R. P. Pictet, and exhibited for the first time in
Great Britain the working of the Cailletet apparatus. Six years later,
in the same place, he described the researches of Z. F. Wroblewski and
K. S. Olszewski, and illustrated for the first time in public the
liquefaction of oxygen and air, by means of apparatus specially designed
for optical projection so that the actions taking place might be visible
to the audience. Soon afterwards he constructed a machine from which the
liquefied gas could be drawn off through a valve for use as a cooling
agent, and he showed its employment for this purpose in connexion with
some researches on meteorites; about the same time he also obtained
oxygen in the solid state. By 1891 he had designed and erected at the
Royal Institution an apparatus which yielded liquid oxygen by the pint,
and towards the end of that year he showed that both liquid oxygen and
liquid ozone are strongly attracted by a magnet. About 1892 the idea
occurred to him of using vacuum-jacketed vessels for the storage of
liquid gases, and so efficient did this device prove in preventing the
influx of external heat that it is found possible not only to preserve
the liquids for comparatively long periods, but also to keep them so
free from ebullition that examination of their optical properties
becomes possible. He next experimented with a high-pressure hydrogen jet
by which low temperatures were realized through the Thomson-Joule
effect, and the successful results thus obtained led him to build at the
Royal Institution the large refrigerating machine by which in 1898
hydrogen was for the first time collected in the liquid state, its
solidification following in 1899. Later he investigated the
gas-absorbing powers of charcoal when cooled to low temperatures, and
applied them to the production of high vacua and to gas analysis (see
LIQUID GASES). The Royal Society in 1894 bestowed the Rumford medal upon
him for his work in the production of low temperatures, and in 1899 he
became the first recipient of the Hodgkins gold medal of the Smithsonian
Institution, Washington, for his contributions to our knowledge of the
nature and properties of atmospheric air. In 1904 he was the first
British subject to receive the Lavoisier medal of the French Academy of
Sciences, and in 1906 he was the first to be awarded the Matteucci medal
of the Italian Society of Sciences. He was knighted in 1904, and in 1908
he was awarded the Albert medal of the Society of Arts.


DEWAS, two native states of India, in the Malwa Political Charge of
Central India, founded in the first half of the 18th century by two
brothers, Punwar Mahrattas, who came into Malwa with the peshwa, Baji
Rao, in 1728. Their descendants are known as the senior and junior
branches of the family, and since 1841 each has ruled his own portion as
a separate state, though the lands belonging to each are so intimately
entangled, that even in Dewas, the capital town, the two sides of the
main street are under different administrations and have different
arrangements for water supply and lighting. The senior branch has an
area of 446 sq. m. and a population of 62,312, while the area of the
junior branch is 440 sq. m. and its population 54,904.


DEWBERRY, _Rubus caesius_, a trailing plant, allied to the bramble, of
the natural order Rosaceae. It is common in woods, hedges and the
borders of fields in England and other countries of Europe. The leaves
have three leaflets, are hairy beneath, and of a dusky green; the
flowers which appear in June and July are white, or pale rose-coloured.
The fruit is large, and closely embraced by the calyx, and consists of a
few drupules, which are black, with a glaucous bloom; it has an
agreeable acid taste.


DEW-CLAW, the rudimentary toes, two in number, or the "false hoof" of
the deer, sometimes also called the "nails." In dogs the dew-claw is the
rudimentary toe or hallux (corresponding to the big toe in man) hanging
loosely attached to the skin, low down on the hinder part of the leg.
The origin of the word is unknown, but it has been fancifully suggested
that, while the other toes touch the ground in walking, the dew-claw
merely brushes the dew from the grass.


D'EWES, SIR SIMONDS, Bart. (1602-1650), English antiquarian, eldest son
of Paul D'Ewes of Milden, Suffolk, and of Cecilia, daughter and heir of
Richard Simonds, of Coaxdon or Coxden, Dorsetshire, was born on the 18th
of December 1602, and educated at the grammar school of Bury St Edmunds,
and at St John's College, Cambridge. He had been admitted to the Middle
Temple in 1611, and was called to the bar in 1623, when he immediately
began his collections of material and his studies in history and
antiquities. In 1626 he married Anne, daughter and heir of Sir William
Clopton, of Luton's Hall in Suffolk, through whom he obtained a large
addition to his already considerable fortune. On the 6th of December he
was knighted. He took an active part as a strong Puritan and member of
the moderate party in the opposition to the king's arbitrary government
in the Long Parliament of 1640, in which he sat as member for Sudbury.
On the 15th of July he was created a baronet by the king, but
nevertheless adhered to the parliamentary party when war broke out, and
in 1643 took the Covenant. He was one of the members expelled by Pride's
Purge in 1648, and died on the 18th of April 1650. He had married
secondly Elizabeth, daughter of Sir Henry Willoughby, Bart., of Risley
in Derbyshire, by whom he had a son, who succeeded to his estates and
title, the latter becoming extinct on the failure of male issue in 1731.
D'Ewes appears to have projected a work of very ambitious scope, no less
than the whole history of England based on original documents. But
though excelling as a collector of materials, and as a laborious,
conscientious and accurate transcriber, he had little power of
generalization or construction, and died without publishing anything
except an uninteresting tract, _The Primitive Practice for Preserving
Truth_ (1645), and some speeches. His _Journals of all the Parliaments
during the Reign of Queen Elizabeth_, however, a valuable work, was
published in 1682. His large collections, including transcripts from
ancient records, many of the originals of which are now dispersed or
destroyed, are in the Harleian collection in the British Museum. His
unprinted Diaries from 1621-1624 and from 1643-1647, the latter valuable
for the notes of proceedings in parliament, are often the only authority
for incidents and speeches during that period, and are amusing from the
glimpses the diarist affords of his own character, his good estimation
of himself and his little jealousies; some are in a cipher and some in
Latin.

  Extracts from his _Autobiography and Correspondence_ from the MSS. in
  the British Museum were published by J. O. Halliwell-Phillips in 1845,
  by Hearne in the appendix to his _Historia vitae et regni Ricardi II._
  (1729), and in the _Bibliotheca topographica Britannica_, No. xv. vol.
  vi. (1783); and from a Diary of later date, _College Life in the Time
  of James I._ (1851). His Diaries have been extensively drawn upon by
  Forster, Gardiner, and by Sanford in his _Studies of the Great
  Rebellion_. Some of his speeches have been reprinted in the Harleian
  Miscellany and in the Somers Tracts.


DE WET, CHRISTIAN (1854- ), Boer general and politician, was born on the
7th of October 1854 at Leeuwkop, Smithfield district (Orange Free
State), and later resided at Dewetsdorp. He served in the first
Anglo-Boer War of 1880-81 as a field cornet, and from 1881 to 1896 he
lived on his farm, becoming in 1897 member of the Volksraad. He took
part in the earlier battles of the Boer War of 1899 in Natal as a
commandant and later, as a general, he went to serve under Cronje in the
west. His first successful action was the surprise of Sanna's Post near
Bloemfontein, which was followed by the victory of Reddersburg a little
later. Thenceforward he came to be regarded more and more as the most
formidable leader of the Boers in their guerrilla warfare. Sometimes
severely handled by the British, sometimes escaping only by the
narrowest margin of safety from the columns which attempted to surround
him, and falling upon and annihilating isolated British posts, De Wet
continued to the end of the war his successful career, striking heavily
where he could do so and skilfully evading every attempt to bring him to
bay. He took an active part in the peace negotiations of 1902, and at
the conclusion of the war he visited Europe with the other Boer
generals. While in England the generals sought, unavailingly, a
modification of the terms of peace concluded at Pretoria. De Wet wrote
an account of his campaigns, an English version of which appeared in
November 1902 under the title _Three Years' War_. In November, 1907 he
was elected a member of the first parliament of the Orange River Colony
and was appointed minister of agriculture. In 1908-9 he was a delegate
to the Closer Union Convention.


DE WETTE, WILHELM MARTIN LEBERECHT (1780-1849), German theologian, was
born on the 12th of January 1780, at Ulla, near Weimar, where his father
was pastor. He was sent to the gymnasium at Weimar, then at the height
of its literary glory. Here he was much influenced by intercourse with
Johann Gottfried Herder, who frequently examined at the school. In 1799
he entered on his theological studies at Jena, his principal teachers
being J. J. Griesbach and H. E. G. Paulus, from the latter of whom he
derived his tendency to free critical inquiry. Both in methods and in
results, however, he occupied an almost solitary position among German
theologians. Having taken his doctor's degree, he became _privat-docent_
at Jena; in 1807 professor of theology at Heidelberg, where he came
under the influence of J. F. Fries (1773-1843); and in 1810 was
transferred to a similar chair in the newly founded university of
Berlin, where he enjoyed the friendship of Schleiermacher. He was,
however, dismissed from Berlin in 1819 on account of his having written
a letter of consolation to the mother of Karl Ludwig Sand, the murderer
of Kotzebue. A petition in his favour presented by the senate of the
university was unsuccessful, and a decree was issued not only depriving
him of the chair, but banishing him from the Prussian kingdom. He
retired for a time to Weimar, where he occupied his leisure in the
preparation of his edition of Luther, and in writing the romance
_Theodor oder die Weihe des Zweiflers_ (Berlin, 1822), in which he
describes the education of an evangelical pastor. During this period he
made his first essay in preaching, and proved himself to be possessed of
very popular gifts. But in 1822 he accepted the chair of theology in the
university of Basel, which had been reorganized four years before.
Though his appointment had been strongly opposed by the orthodox party,
De Wette soon won for himself great influence both in the university and
among the people generally. He was admitted a citizen, and became rector
of the university, which owed to him much of its recovered strength,
particularly in the theological faculty. He died on the 16th of June
1849.

De Wette has been described by Julius Wellhausen as "the epoch-making
opener of the historical criticism of the Pentateuch." He prepared the
way for the Supplement-theory. But he also made valuable contributions
to other branches of theology. He had, moreover, considerable poetic
faculty, and wrote a drama in three acts, entitled _Die Entsagung_
(Berlin, 1823). He had an intelligent interest in art, and studied
ecclesiastical music and architecture. As a Biblical critic he is
sometimes classed with the destructive school, but, as Otto Pfleiderer
says (_Development of Theology_, p. 102), he "occupied as free a
position as the Rationalists with regard to the literal authority of the
creeds of the church, but that he sought to give their due value to the
religious feelings, which the Rationalists had not done, and, with a
more unfettered mind towards history, to maintain the connexion of the
present life of the church with the past." His works are marked by
exegetical skill, unusual power of condensation and uniform fairness.
Accordingly they possess value which is little affected by the progress
of criticism.

  The most important of his works are:--_Beiträge zur Einleitung in das
  Alte Testament_ (2 vols., 1806-1807); _Kommentar über die Psalmen_
  (1811), which has passed through several editions, and is still
  regarded as of high authority; _Lehrbuch der hebräisch-jüdischen
  Archäologie_ (1814); _Über Religion und Theologie_ (1815); a work of
  great importance as showing its author's general theological position;
  _Lehrbuch der christlichen Dogmatik_ (1813-1816); _Lehrbuch der
  historisch-kritischen Einleitung in die Bibel_ (1817); _Christliche
  Sittenlehre_ (1819-1821); _Einleitung in das Neue Testament_ (1826);
  _Religion, ihr Wesen, ihre Erscheinungsform, und ihr Einfluss auf das
  Leben_ (1827); _Das Wesen des christlichen Glaubens_ (1846); and
  _Kurzgefasstes exegetisches Handbuch zum Neuen Testament_ (1836-1848).
  De Wette also edited Luther's works (5 vols., 1825-1828).

   See K. R. Hagenbach in _Herzog's Realencyklopädie_; G. C. F. Lücke's
  _W. M. L. De Wette, zur freundschaftlicher Erinnerung_ (1850); and D.
  Schenkel's _W. M. L. De Wette und die Bedeutung seiner Theologie für
  unsere Zeit_ (1849). Rudolf Stähelin, _De Wette nach seiner theol.
  Wirksamkeit und Bedeutung_ (1880); F. Lichtenberger, _History of
  German Theology in the Nineteenth Century_ (1889); Otto Pfleiderer,
  _Development of Theology_ (1890), pp. 97 ff.; T. K. Cheyne, _Founders
  of the Old Testament Criticism_, pp. 31 ff.


DEWEY, DAVIS RICH (1858- ), American economist and statistician, was
born at Burlington, Vermont, U.S.A., on the 7th of April 1858. He was
educated at the university of Vermont and at Johns Hopkins University,
and afterwards became professor of economics and statistics at the
Massachusetts Institute of Technology. He was chairman of the state
board on the question of the unemployed (1895), member of the
Massachusetts commission on public, charitable and reformatory interests
(1897), special expert agent on wages for the 12th census, and member of
a state commission (1904) on industrial relations. He wrote an excellent
_Syllabus on Political History since 1815_ (1887), a _Financial History
of the U.S._ (1902), and _National Problems_ (1907).


DEWEY, GEORGE (1837- ), American naval officer, was born at Montpelier,
Vermont, on the 26th of December 1837. He studied at Norwich University,
then at Norwich, Vermont, and graduated at the United States Naval
Academy in 1858. He was commissioned lieutenant in April 1861, and in
the Civil War served on the steamsloop "Mississippi" (1861-1863) during
Farragut's passage of the forts below New Orleans in April 1862, and at
Port Hudson in March 1863; took part in the fighting below
Donaldsonville, Louisiana, in July 1863; and in 1864-1865 served on the
steam-gunboat "Agawam" with the North Atlantic blockading squadron and
took part in the attacks on Fort Fisher in December 1864 and January
1865. In March 1865 he became a lieutenant-commander. He was with the
European squadron in 1866-1867; was an instructor in the United States
Naval Academy in 1868-1869; was in command of the "Narragansett" in
1870-1871 and 1872-1875, being commissioned commander in 1872; was
light-house inspector in 1876-1877; and was secretary of the light-house
board in 1877-1882. In 1884 he became a captain; in 1889-1893 was chief
of the bureau of equipment and recruiting; in 1893-1895 was a member of
the light-house board; and in 1895-1897 was president of the board of
inspection and survey, being promoted to the rank of commodore in
February 1896. In November 1897 he was assigned, at his own request, to
sea service, and sent to Asiatic waters. In April 1898, while with his
fleet at Hong Kong, he was notified by cable that war had begun between
the United States and Spain, and was ordered to "capture or destroy the
Spanish fleet" then in Philippine waters. On the 1st of May he
overwhelmingly defeated the Spanish fleet under Admiral Montojo in
Manila Bay, a victory won without the loss of a man on the American
ships (see SPANISH-AMERICAN WAR). Congress, in a joint resolution,
tendered its thanks to Commodore Dewey, and to the officers and men
under his command, and authorized "the secretary of the navy to present
a sword of honor to Commodore George Dewey, and cause to be struck
bronze medals commemorating the battle of Manila Bay, and to distribute
such medals to the officers and men of the ships of the Asiatic squadron
of the United States." He was promoted rear-admiral on the 10th of May
1898. On the 18th of August his squadron assisted in the capture of the
city of Manila. After remaining in the Philippines under orders from his
government to maintain control, Dewey received the rank of admiral
(March 3, 1899)--that title, formerly borne only by Farragut and Porter,
having been revived by act of Congress (March 2, 1899),--and returned
home, arriving in New York City, where, on the 3rd of October 1899, he
received a great ovation. He was a member (1899) of the Schurman
Philippine Commission, and in 1899 and 1900 was spoken of as a possible
Democratic candidate for the presidency. He acted as president of the
Schley court of inquiry in 1901, and submitted a minority report on a
few details.


DEWEY, MELVIL (1851- ), American librarian, was born at Adams Center,
New York, on the 10th of December 1851. He graduated in 1874 at Amherst
College, where he was assistant librarian from 1874 to 1877. In 1877 he
removed to Boston, where he founded and became editor of _The Library
Journal_, which became an influential factor in the development of
libraries in America, and in the reform of their administration. He was
also one of the founders of the American Library Association, of which
he was secretary from 1876 to 1891, and president in 1891 and 1893. In
1883 he became librarian of Columbia College, and in the following year
founded there the School of Library Economy, the first institution for
the instruction of librarians ever organized. This school, which was
very successful, was removed to Albany in 1890, where it was
re-established as the State Library School under his direction; from
1888 to 1906 he was director of the New York State Library and from 1888
to 1900 was secretary of the University of the State of New York,
completely reorganizing the state library, which he made one of the most
efficient in America, and establishing the system of state travelling
libraries and picture collections. His "Decimal System of
Classification" for library cataloguing, first proposed in 1876, is
extensively used.


DEWING, THOMAS WILMER (1851- ), American figure painter, was born in
Boston, Massachusetts, on the 4th of May 1851. He was a pupil of Jules
Lefebvre in Paris from 1876 to 1879; was elected a full member of the
National Academy of Design in 1888; was a member of the society of Ten
American Painters, New York; and received medals at the Paris Exhibition
(1889), at Chicago (1893), at Buffalo (1901) and at St Louis (1904). His
decorative genre pictures are notable for delicacy and finish. Among his
portraits are those of Mrs Stanford White and of his own wife. Mrs
Dewing (b, 1855), _née_ Maria Oakey, a figure and flower painter, was a
pupil of John La Farge in New York, and of Couture in Paris.


DE WINT, PETER (1784-1849), English landscape painter, of Dutch
extraction, son of an English physician, was born at Stone,
Staffordshire, on the 21st of January 1784. He studied art in London,
and in 1809 entered the Academy schools. In 1812 he became a member of
the Society of Painters in Watercolours, where he exhibited largely for
many years, as well as at the Academy. He married in 1810 the sister of
William Hilton, R.A. He died in London on the 30th of January 1849. De
Wint's life was devoted to art; he painted admirably in oils, and he
ranks as one of the chief English water-colourists. A number of his
pictures are in the National Gallery and the Victoria and Albert Museum.


DE WINTER, JAN WILLEM (1750-1812), Dutch admiral, was born at Kampen,
and in 1761 entered the naval service at the age of twelve years. He
distinguished himself by his zeal and courage, and at the revolution of
1787 he had reached the rank of lieutenant. The overthrow of the
"patriot" party forced him to fly for his safety to France. Here he
threw himself heart and soul into the cause of the Revolution, and took
part under Dumouriez and Pichegru in the campaigns of 1792 and 1793, and
was soon promoted to the rank of brigadier-general. When Pichegru in
1795 overran Holland, De Winter returned with the French army to his
native country. The states-general now utilized the experience he had
gained as a naval officer by giving him the post of adjunct-general for
the reorganization of the Dutch navy. In 1796 he was appointed
vice-admiral and commander-in-chief of the fleet. He spared no efforts
to strengthen it and improve its condition, and on the 11th of October
1797 he ventured upon an encounter off Camperdown with the British fleet
under Admiral Duncan. After an obstinate struggle the Dutch were
defeated, and De Winter himself was taken prisoner. He remained in
England until December, when he was liberated by exchange. His conduct
in the battle of Camperdown was declared by a court-martial to have
nobly maintained the honour of the Dutch flag.

From 1798 to 1802 De Winter filled the post of ambassador to the French
republic, and was then once more appointed commander of the fleet. He
was sent with a strong squadron to the Mediterranean to repress the
Tripoli piracies, and negotiated a treaty of peace with the Tripolitan
government. He enjoyed the confidence of Louis Bonaparte, when king of
Holland, and, after the incorporation of the Netherlands in the French
empire, in an equal degree of the emperor Napoleon. By the former he was
created marshal and count of Huessen, and given the command of the armed
forces both by sea and land. Napoleon gave him the grand cross of the
Legion of Honour and appointed him inspector-general of the northern
coasts, and in 1811 he placed him at the head of the fleet he had
collected at the Texel. Soon afterwards De Winter was seized with
illness and compelled to betake himself to Paris, where he died on the
2nd of June 1812. He had a splendid public funeral and was buried in the
Pantheon. His heart was enclosed in an urn and placed in the Nicolaas
Kerk at Kampen.


DE WITT, CORNELIUS (1623-1672), brother of JOHN DE WITT (q.v.), was born
at Dort in 1623. In 1650 he became burgomaster of Dort and member of the
states of Holland and West Friesland. He was afterwards appointed to the
important post of _ruwaard_ or governor of the land of Putten and
bailiff of Beierland. He associated himself closely with his greater
brother, the grand pensionary, and supported him throughout his career
with great ability and vigour. In 1667 he was the deputy chosen by the
states of Holland to accompany Admiral de Ruyter in his famous
expedition to Chatham. Cornelius de Witt on this occasion distinguished
himself greatly by his coolness and intrepidity. He again accompanied De
Ruyter in 1672 and took an honourable part in the great naval fight at
Sole Bay against the united English and French fleets. Compelled by
illness to leave the fleet, he found on his return to Dort that the
Orange party were in the ascendant, and he and his brother were the
objects of popular suspicion and hatred. An account of his imprisonment,
trial and death, is given below.


DE WITT, JOHN (1625-1672), Dutch statesman, was born at Dort, on the
24th of September 1625. He was a member of one of the old burgher-regent
families of his native town. His father, Jacob de Witt, was six times
burgomaster of Dort, and for many years sat as a representative of the
town in the states of Holland. He was a strenuous adherent of the
republican or oligarchical states-right party in opposition to the
princes of the house of Orange, who represented the federal principle
and had the support of the masses of the people. John was educated at
Leiden, and early displayed remarkable talents, more especially in
mathematics and jurisprudence. In 1645 he and his elder brother
Cornelius visited France, Italy, Switzerland and England, and on his
return he took up his residence at the Hague, as an advocate. In 1650 he
was appointed pensionary of Dort, an office which made him the leader
and spokesman of the town's deputation in the state of Holland. In this
same year the states of Holland found themselves engaged in a struggle
for provincial supremacy, on the question of the disbanding of troops,
with the youthful prince of Orange, William II. William, with the
support of the states-general and the army, seized five of the leaders
of the states-right party and imprisoned them in Loevestein castle;
among these was Jacob de Witt. The sudden death of William, at the
moment when he had crushed opposition, led to a reaction. He left only a
posthumous child, afterwards William III. of Orange, and the principles
advocated by Jacob de Witt triumphed, and the authority of the states of
Holland became predominant in the republic.

At this time of constitutional crisis such were the eloquence, sagacity
and business talents exhibited by the youthful pensionary of Dort that
on the 23rd of July 1653 he was appointed to the office of grand
pensionary (_Raadpensionaris_) of Holland at the age of twenty-eight. He
was re-elected in 1658, 1663 and 1668, and held office until his death
in 1672. During this period of nineteen years the general conduct of
public affairs and administration, and especially of foreign affairs,
such was the confidence inspired by his talents and industry, was
largely placed in his hands. He found in 1653 his country brought to the
brink of ruin through the war with England, which had been caused by the
keen commercial rivalry of the two maritime states. The Dutch were
unprepared, and suffered severely through the loss of their carrying
trade, and De Witt resolved to bring about peace as soon as possible.
The first demands of Cromwell were impossible, for they aimed at the
absorption of the two republics into a single state, but at last in the
autumn of 1654 peace was concluded, by which the Dutch made large
concessions and agreed to the striking of the flag to English ships in
the narrow seas. The treaty included a secret article, which the
states-general refused to entertain, but which De Witt succeeded in
inducing the states of Holland to accept, by which the provinces of
Holland pledged themselves not to elect a stadtholder or a
captain-general of the union. This Act of Seclusion, as it was called,
was aimed at the young prince of Orange, whose close relationship to the
Stuarts made him an object of suspicion to the Protector. De Witt was
personally favourable to this exclusion of William III. from his
ancestral dignities, but there is no truth in the suggestion that he
prompted the action of Cromwell in this matter.

The policy of De Witt after the peace of 1654 was eminently successful.
He restored the finances of the state, and extended its commercial
supremacy in the East Indies. In 1658-59 he sustained Denmark against
Sweden, and in 1662 concluded an advantageous peace with Portugal. The
accession of Charles II. to the English throne led to the rescinding of
the Act of Seclusion; nevertheless De Witt steadily refused to allow the
prince of Orange to be appointed stadtholder or captain-general. This
led to ill-will between the English and Dutch governments, and to a
renewal of the old grievances about maritime and commercial rights, and
war broke out in 1665. The zeal, industry and courage displayed by the
grand pensionary during the course of this fiercely contested naval
struggle could scarcely have been surpassed. He himself on more than one
occasion went to sea with the fleet, and inspired all with whom he came
in contact by the example he set of calmness in danger, energy in action
and inflexible strength of will. It was due to his exertions as an
organizer and a diplomatist quite as much as to the brilliant seamanship
of Admiral de Ruyter, that the terms of the treaty of peace signed at
Breda (July 31, 1667), on the principle of _uti possidetis_, were so
honourable to the United Provinces. A still greater triumph of
diplomatic skill was the conclusion of the Triple Alliance (January 17,
1668) between the Dutch Republic, England and Sweden, which checked the
attempt of Louis XIV. to take possession of the Spanish Netherlands in
the name of his wife, the infanta Maria Theresa. The check, however, was
but temporary, and the French king only bided his time to take vengeance
for the rebuff he had suffered. Meanwhile William III. was growing to
manhood, and his numerous adherents throughout the country spared no
efforts to undermine the authority of De Witt, and secure for the young
prince of Orange the dignities and authority of his ancestors.

In 1672 Louis XIV. suddenly declared war, and invaded the United
Provinces at the head of a splendid army. Practically no resistance was
possible. The unanimous voice of the people called William III. to the
head of affairs, and there were violent demonstrations against John de
Witt. His brother Cornelius was (July 24) arrested on a charge of
conspiring against the prince. On the 4th of August John de Witt
resigned the post of grand pensionary that he had held so long and with
such distinction. Cornelius was put to the torture, and on the 19th of
August he was sentenced to deprivation of his offices and banishment. He
was confined in the Gevangenpoort, and his brother came to visit him in
the prison. A vast crowd on hearing this collected outside, and finally
burst into the prison, seized the two brothers and literally tore them
to pieces. Their mangled remains were hung up by the feet to a
lamp-post. Thus perished, by the savage act of an infuriated mob, one of
the greatest statesmen of his age.

John de Witt married Wendela Bicker, daughter of an influential
burgomaster of Amsterdam, in 1655, by whom he had two sons and three
daughters.

  BIBLIOGRAPHY.--J. Geddes, _History of the Administration of John de
  Witt_, (vol. i. only, London, 1879); A. Lefèvre-Pontalis, _Jean de
  Witt, grand pensionnaire de Hollande_ (2 vols., Paris, 1884); P.
  Simons, _Johan de Witt en zijn tijd_ (3 vols., Amsterdam, 1832-1842);
  W. C. Knottenbelt, _Geschiedenis der Staatkunde van J. de Witt_
  (Amsterdam, 1862); _J. de Witt, Brieven ... gewisselt tusschen den
  Heer Johan de Witt ... ende de gevolgmaghtigden v. d. staedt d.
  Vereen. Nederlanden so in Vranckryck, Engelandt, Sweden, Denemarken,
  Poolen, enz. 1652-69_ (6 vols., The Hague, 1723-1725); _Brieven ...
  1650-1657 (1658) eerste deel bewerkt den R. Fruin uitgegeven d., C. W.
  Kernkamp_ (Amsterdam, 1906).


DEWLAP (from the O.E. _læppa_, a lappet, or hanging fold; the first
syllable is of doubtful origin and the popular explanation that the word
means "the fold which brushes the dew" is not borne out, according to
the _New English Dictionary_, by the equivalent words such as the
Danish _doglaeb_, in Scandinavian languages), the loose fold of skin
hanging from the neck of cattle, also applied to similar folds in the
necks of other animals and fowls, as the dog, turkey, &c. The American
practice of branding cattle by making a cut in the neck is known as a
"dewlap brand." The skin of the neck in human beings often becomes
pendulous with age, and is sometimes referred to humorously by the same
name.


DEWSBURY, a market town and municipal and parliamentary borough in the
West Riding of Yorkshire, England, on the river Calder, 8 m. S.S.W. of
Leeds, on the Great Northern, London & North-Western, and Lancashire &
Yorkshire railways. Pop. (1901) 28,060. The parish church of All Saints
was for the most part rebuilt in the latter half of the 18th century;
the portions still preserved of the original structure are mainly Early
English. The chief industries are the making of blankets, carpets,
druggets and worsted yarn; and there are iron foundries and machinery
works. Coal is worked in the neighbourhood. The parliamentary borough
includes the adjacent municipal borough of Batley, and returns one
member. The municipal borough, incorporated in 1862, is under a mayor, 6
aldermen and 18 councillors. Area, 1471 acres. Paulinus, first
archbishop of York, about the year 627 preached in the district of
Dewsbury, where Edwin, king of Northumbria, whom he converted to
Christianity, had a royal mansion. At Kirklees, in the parish, are
remains of a Cistercian convent of the 12th century, in an extensive
park, where tradition relates that Robin Hood died and was buried.


DEXIPPUS, PUBLIUS HERENNIUS (c. A.D. 210-273), Greek historian,
statesman and general, was an hereditary priest of the Eleusinian family
of the Kerykes, and held the offices of archon basileus and eponymus in
Athens. When the Heruli overran Greece and captured Athens (269),
Dexippus showed great personal courage and revived the spirit of
patriotism among his degenerate fellow-countrymen. A statue was set up
in his honour, the base of which, with an inscription recording his
services, has been preserved (_Corpus Inscrr. Atticarum_, iii. No. 716).
It is remarkable that the inscription is silent as to his military
achievements. Photius (_cod._ 82) mentions three historical works by
Dexippus, of which considerable fragments remain: (1) [Greek: Ta met'
Alexandron], an epitome of a similarly named work by Arrian; (2) [Greek:
Skuthika], a history of the wars of Rome with the Goths (or Scythians)
in the 3rd century; (3) [Greek: Chronikê historia], a chronological
history from the earliest times to the emperor Claudius Gothicus (270),
frequently referred to by the writers of the Augustan history. The work
was continued by Eunapius of Sardis down to 404. Photius speaks very
highly of the style of Dexippus, whom he places on a level with
Thucydides, an opinion by no means confirmed by the fragments (C. W.
Müller, _F.H.G._ iii. 666-687).


DEXTER, HENRY MARTYN (1821-1890), American clergyman and author, was
born in Plympton, Massachusetts, on the 13th of August 1821. He
graduated at Yale in 1840 and at the Andover Theological Seminary in
1844; was pastor of a Congregational church in Manchester, New
Hampshire, in 1844-1849, and of the Berkeley Street Congregational
church, Boston, in 1849-1867; was an editor of the _Congregationalist_
in 1851-1866, of the _Congregational Quarterly_ in 1859-1866, and of the
_Congregationalist_, with which the _Recorder_ was merged, from 1867
until his death in New Bedford, Mass., on the 13th of November 1890. He
was an authority on the history of Congregationalism and was lecturer on
that subject at the Andover Theological Seminary in 1877-1879; he left
his fine library on the Puritans in America to Yale University. Among
his works are: _Congregationalism, What it is, Whence it is, How it
works, Why it is better than any other Form of Church Government, and
its consequent Demands_ (1865), _The Church Polity of the Puritans the
Polity of the New Testament_ (1870), _As to Roger Williams and His
"Banishment" from the Massachusetts Colony_ (1876), _Congregationalism
of the Last Three Hundred Years, as seen in its Literature_ (1880), his
most important work, _A Handbook of Congregationalism_ (1880), _The True
Story of John Smyth, the "Se-Baptist"_ (1881), _Common Sense as to
Woman Suffrage_ (1885), and many reprints of pamphlets bearing on early
church history in New England, especially Baptist controversies. His
_The England and Holland of the Pilgrims_ was completed by his son,
Morton Dexter (b. 1846), and published in 1905.


DEXTER, TIMOTHY (1747-1806), American merchant, remarkable for his
eccentricities, was born at Malden, Massachusetts, on the 22nd of
February 1747. He acquired considerable wealth by buying up quantities
of the depreciated continental currency, which was ultimately redeemed
by the Federal government at par. He assumed the title of Lord Dexter
and built extraordinary houses at Newburyport, Mass., and Chester, New
Hampshire. He maintained a poet laureate and collected inferior
pictures, besides erecting in one of his gardens some forty colossal
statues carved in wood to represent famous men. A statue of himself was
included in the collection, and had for an inscription "I am the first
in the East, the first in the West, and the greatest philosopher in the
Western World." He wrote a book entitled _Pickle for the Knowing Ones_.
It was wholly without punctuation marks, and as this aroused comment, he
published a second edition, at the end of which was a page displaying
nothing but commas and stops, from which the readers were invited to
"peper and solt it as they plese." He beat his wife for not weeping
enough at the rehearsal of his funeral, which he himself carried out in
a very elaborate manner. He died at Newburyport on the 26th of October
1806.


DEXTRINE (BRITISH GUM, STARCH GUM, LEIOCOME), (C_{6}H_{10}O_{5})_{x}, a
substance produced from starch by the action of dilute acids, or by
roasting it at a temperature between 170° and 240° C. It is manufactured
by spraying starch with 2% nitric acid, drying in air, and then heating
to about 110°. Different modifications are known, e.g. amylodextrine,
erythrodextrine and achroodextrine. Its name has reference to its
powerful dextrorotatory action on polarized light. Pure dextrine is an
insipid, odourless, white substance; commercial dextrine is sometimes
yellowish, and contains burnt or unchanged starch. It dissolves in water
and dilute alcohol; by strong alcohol it is precipitated from its
solutions as the hydrated compound, C_{6}H_{10}O_{5}.H_{2}O. Diastase
converts it eventually into maltose, C_{12}H_{22}O_{11}; and by boiling
with dilute acids (sulphuric, hydrochloric, acetic) it is transformed
into dextrose, or ordinary glucose, C_{6}H_{12}O_{6}. It does not
ferment in contact with yeast, and does not reduce Fehling's solution.
If heated with strong nitric acid it gives oxalic, and not mucic acid.
Dextrine much resembles gum arabic, for which it is generally
substituted. It is employed for sizing paper, for stiffening cotton
goods, and for thickening colours in calico printing, also in the making
of lozenges, adhesive stamps and labels, and surgical bandages.

  See Otto Lueger, _Lexikon der gesamten Technik_.


DEY (an adaptation of the Turk, d[=a]î, a maternal uncle), an
honorary title formerly bestowed by the Turks on elderly men,
and appropriated by the janissaries as the designation of their
commanding officers. In Algeria the deys of the janissaries
became in the 17th century rulers of that country (see ALGERIA:
HISTORY). From the middle of the 16th century to the end of the
17th century the ruler of Tunisia was also called dey, a title
frequently used during the same period by the sovereigns of
Tripoli.


DHAMMAP[=A]LA, the name of one of the early disciples of the Buddha, and
therefore constantly chosen as their name in religion by Buddhist
novices on their entering the brotherhood. The most famous of the
Bhikshus so named was the great commentator who lived in the latter half
of the 5th century A.D. at the Badara Tittha Vih[=a]ra, near the east
coast of India, just a little south of where Madras now stands. It is to
him we owe the commentaries on seven of the shorter canonical books,
consisting almost entirely of verses, and also the commentary on the
Netti, perhaps the oldest P[=a]li work outside the canon. Extracts from
the latter work, and the whole of three out of the seven others, have
been published by the P[=a]li Text Society. These works show great
learning, exegetical skill and sound judgment. But as Dhammap[=a]la
confines himself rigidly either to questions of the meaning of words,
or to discussions of the ethical import of his texts, very little can be
gathered from his writings of value for the social history of his time.
For the right interpretation of the difficult texts on which he
comments, they are indispensable. Though in all probability a Tamil by
birth, he declares, in the opening lines of those of his works that have
been edited, that he followed the tradition of the Great Minster at
Anur[=a]dhapura in Ceylon, and the works themselves confirm this in
every respect. Hsüan Tsang, the famous Chinese pilgrim, tells a quaint
story of a Dhammap[=a]la of K[=a]nchipura (the modern Konjevaram). He
was a son of a high official, and betrothed to a daughter of the king,
but escaped on the eve of the wedding feast, entered the order, and
attained to reverence and distinction. It is most likely that this
story, whether legendary or not (and Hsüan Tsang heard the story at
K[=a]nchipura nearly two centuries after the date of Dhammap[=a]la),
referred to this author. But it may also refer, as Hsüan Tsang refers
it, to another author of the same name. Other unpublished works, besides
those mentioned above, have been ascribed to Dhammap[=a]la, but it is
very doubtful whether they are really by him.

  AUTHORITIES.--T. Watters, _On Yuan Chwang_ (ed. Rhys Davids and
  Bushell, London, 1905), ii. 169, 228; Edmund Hardy in _Zeitschrift der
  deutschen morgenländischen Gesellschaft_ (1898), pp. 97 foll.; _Netti_
  (ed. E. Hardy, London, P[=a]li Text Society, 1902), especially the
  Introduction, passim; _Therî G[=a]th[=a] Commentary_, _Peta Vatthu
  Commentary_, and _Vim[=a]na Vatthu Commentary_, all three published by
  the P[=a]li Text Society.                              (T. W. R. D.)


DHANIS, FRANCIS, BARON (1861-1909), Belgian administrator, was born in
London in 1861 and passed the first fourteen years of his life at
Greenock, where he received his early education. He was the son of a
Belgian merchant and of an Irish lady named Maher. The name Dhanis is
supposed to be a variation of D'Anvers. Having completed his education
at the École Militaire he entered the Belgian army, joining the regiment
of grenadiers, in which he rose to the rank of major. As soon as he
reached the rank of lieutenant he volunteered for service on the Congo,
and in 1887 he went out for a first term. He did so well in founding new
stations north of the Congo that, when the government decided to put an
end to the Arab domination on the Upper Congo, he was selected to
command the chief expedition sent against the slave dealers. The
campaign began in April 1892, and it was not brought to a successful
conclusion till January 1894. The story of this war has been told in
detail by Dr Sydney Hinde, who took part in it, in his book _The Fall of
the Congo Arabs_. The principal achievements of the campaign were the
captures in succession of the three Arab strongholds at Nyangwe,
Kassongo and Kabambari. For his services Dhanis was raised to the rank
of baron, and in 1895 was made vice-governor of the Congo State. In 1896
he took command of an expedition to the Upper Nile. His troops, largely
composed of the Batetela tribes who had only been recently enlisted, and
who had been irritated by the execution of some of their chiefs for
indulging their cannibal proclivities, mutinied and murdered many of
their white officers. Dhanis found himself confronted with a more
formidable adversary than even the Arabs in these well-armed and
half-disciplined mercenaries. During two years (1897-1898) he was
constantly engaged in a life-and-death struggle with them. Eventually he
succeeded in breaking up the several bands formed out of his mutinous
soldiers. Although the incidents of the Batetela operations were less
striking than those of the Arab war, many students of both think that
the Belgian leader displayed the greater ability and fortitude in
bringing them to a successful issue. In 1899 Baron Dhanis returned to
Belgium with the honorary rank of vice governor-general. He died on the
14th of November 1909.


DHAR, a native state of India, in the Bhopawar agency, Central India. It
includes many Rajput and Bhil feudatories, and has an area of 1775 sq.
m. The raja is a Punwar Mahratta. The founder of the present ruling
family was Anand Rao Punwar, a descendant of the great Paramara clan of
Rajputs who from the 9th to the 13th century, when they were driven out
by the Mahommedans, had ruled over Malwa from their capital at Dhar. In
1742 Anand Rao received Dhar as a fief from Baji Rao, the peshwa, the
victory of the Mahrattas thus restoring the sovereign power to the
family which seven centuries before had been expelled from this very
city and country. Towards the close of the 18th and in the early part of
the 19th century, the state was subject to a series of spoliations by
Sindia and Holkar, and was only preserved from destruction by the
talents and courage of the adoptive mother of the fifth raja. By a
treaty of 1819 Dhar passed under British protection, and bound itself to
act in subordinate co-operation. The state was confiscated for rebellion
in 1857, but in 1860 was restored to Raja Anand Rao Punwar, then a
minor, with the exception of the detached district of Bairusia, which
was granted to the begum of Bhopal. Anand Rao, who received the personal
title Maharaja and the K.C.S.I. in 1877, died in 1898, and was succeeded
by Udaji Rao Punwar. In 1901 the population was 142,115. The state
includes the ruins of Mandu, or Mandogarh, the Mahommedan capital of
Malwa.

THE TOWN OF DHAR is 33 m. W. of Mhow, 908 ft. above the sea. Pop. (1901)
17,792. It is picturesquely situated among lakes and trees surrounded by
barren hills, and possesses, besides its old walls, many interesting
buildings, Hindu and Mahommedan, some of them containing records of a
great historical importance. The Lat Masjid, or Pillar Mosque, was built
by Dilawar Khan in 1405 out of the remains of Jain temples. It derives
its name from an iron pillar, supposed to have been originally set up at
the beginning of the 13th century in commemoration of a victory, and
bearing a later inscription recording the seven days' visit to the town
of the emperor Akbar in 1598. The pillar, which was 43 ft. high, is now
overthrown and broken. The Kamal Maula is an enclosure containing four
tombs, the most notable being that of Shaikh Kamal Maulvi
(Kamal-ud-din), a follower of the famous 13th-century Mussulman saint
Nizam-ud-din Auliya.[1] The mosque known as Raja Bhoj's school was built
out of Hindu remains in the 14th or 15th century: its name is derived
from the slabs, covered with inscriptions giving rules of Sanskrit
grammar, with which it is paved. On a small hill to the north of the
town stands the fort, a conspicuous pile of red sandstone, said to have
been built by Mahommed ben Tughlak of Delhi in the 14th century. It
contains the palace of the raja. Of modern institutions may be mentioned
the high school, public library, hospital, and the chapel, school and
hospital of the Canadian Presbyterian mission. There is also a
government opium depot for the payment of duty, the town being a
considerable centre for the trade in opium as well as in grain.

  The town, the name of which is usually derived from Dhara Nagari (the
  city of sword blades), is of great antiquity, and was made the capital
  of the Paramara chiefs of Malwa by Vairisinha II., who transferred his
  headquarters hither from Ujjain at the close of the 9th century.
  During the rule of the Paramara dynasty Dhar was famous throughout
  India as a centre of culture and learning; but, after suffering
  various vicissitudes, it was finally conquered by the Mussulmans at
  the beginning of the 14th century. At the close of the century Dilawar
  Khan, the builder of the Lat Masjid, who had been appointed governor
  in 1399, practically established his independence, his son Hoshang
  Shah being the first Mahommedan king of Malwa. Under this dynasty Dhar
  was second in importance to the capital Mandu. Subsequently, in the
  time of Akbar, Dhar fell under the dominion of the Moguls, in whose
  hands it remained till 1730, when it was conquered by the Mahrattas.

  See _Imperial Gazetteer of India_ (Oxford, 1908).

[1] Nizam-ud-din, whose beautiful marble tomb is at Indarpat near Delhi,
was, according to some authorities, an assassin of the secret society of
Khorasan. By some modern authorities he is supposed to have been the
founder of Thuggism, the Thugs having a special reverence for his
memory.


DHARAMPUR, a native state of India, in the Surat political agency
division of Bombay, with an area of 704 sq. m. The population in 1901
was 100,430, being a decrease of 17% during the decade; the estimated
gross revenue is £25,412; and the tribute £600. Its chief is a Sesodia
Rajput. The state has been surveyed for land revenue on the Bombay
system. It contains one town, Dharampur (pop. in 1901, 63,449), and 272
villages. Only a small part of the state, the climate of which is very
unhealthy, is capable of cultivation; the rest is covered with rocky
hills, forest and brushwood.


DHARMSALA, a hill-station and sanatorium of the Punjab, India, situated
on a spur of the Dhaola Dhar, 16 m. N.E. of Kangra town, at an elevation
of some 6000 ft. Pop. (1901) 6971. The scenery of Dharmsala is of
peculiar grandeur. The spur on which it stands is thickly wooded with
oak and other trees; behind it the pine-clad slopes of the mountain
tower towards the jagged peaks of the higher range, snow-clad for half
the year; while below stretches the luxuriant cultivation of the Kangra
valley. In 1855 Dharmsala was made the headquarters of the Kangra
district of the Punjab in place of Kangra, and became the centre of a
European settlement and cantonment, largely occupied by Gurkha
regiments. The station was destroyed by the earthquake of April 1905, in
which 1625 persons, including 25 Europeans and 112 of the Gurkha
garrison, perished (_Imperial Gazetteer of India_, 1908).


DHARWAR, a town and district of British India, in the southern division
of Bombay. The town has a station on the Southern Mahratta railway. The
population in 1901 was 31,279. It has several ginning factories and a
cotton-mill; two high schools, one maintained by the Government and the
other by the Basel German Mission.

The DISTRICT OF DHARWAR has an area of 4602 sq. m. In the north and
north-east are great plains of black soil, favourable to cotton-growing;
in the south and west are successive ranges of low hills, with flat
fertile valleys between them. The whole district lies high and has no
large rivers.

In 1901 the population was 1,113,298, showing an increase of 6% in the
decade. The most influential classes of the community are Brahmans and
Lingayats. The Lingayats number 436,968, or 46% of the Hindu population;
they worship the symbol of Siva, and males and females both carry this
emblem about their person in a silver case. The principal crops are
millets, pulse and cotton. The centres of the cotton trade are Hubli and
Gadag, junctions on the Southern Mahratta railway, which traverses the
district in several directions.

The early history of the territory comprised within the district of
Dharwar has been to a certain extent reconstructed from the inscription
slabs and memorial stones which abound there. From these it is clear
that the country fell in turn under the sway of the various dynasties
that ruled in the Deccan, memorials of the Chalukyan dynasty, whether
temples or inscriptions, being especially abundant. In the 14th century
the district was first overrun by the Mahommedans, after which it was
annexed to the newly established Hindu kingdom of Vijayanagar, an
official of which named Dhar Rao, according to local tradition, built
the fort at Dharwar town in 1403. After the defeat of the king of
Vijayanagar at Talikot (1565), Dharwar was for a few years practically
independent under its Hindu governor; but in 1573 the fort was captured
by the sultan of Bijapur, and Dharwar was annexed to his dominions. In
1685 the fort was taken by the emperor Aurangzeb, and Dharwar, on the
break-up of the Mogul empire, fell under the sway of the peshwa of
Poona. In 1764 the province was overrun by Hyder Ali of Mysore, who in
1778 captured the fort of Dharwar. This was retaken in 1791 by the
Mahrattas. On the final overthrow of the peshwa in 1817, Dharwar was
incorporated with the territory of the East India Company.


DHOLPUR, a native state of India, in the Rajputana agency, with an area
of 1155 sq. m. It is a crop-producing country, without any special
manufactures. All along the bank of the river Chambal the country is
deeply intersected by ravines; low ranges of hills in the western
portion of the state supply inexhaustible quarries of fine-grained and
easily-worked red sandstone. In 1901 the population of Dholpur was
270,973, showing a decrease of 3% in the decade. The estimated revenue
is £83,000. The state is crossed by the Indian Midland railway from
Jhansi to Agra. In recent years it has suffered severely from drought.
In 1896-1897 the expenditure on famine relief amounted to £8190.

The town of Dholpur is 34 m. S. of Agra by rail. Pop. (1901) 19,310. The
present town, which dates from the 16th century, stands somewhat to the
north of the site of the older Hindu town built, it is supposed, in the
11th century by the Tonwar Rajput Raja Dholan (or Dhawal) Deo, and named
after him Dholdera or Dhawalpuri. Among the objects of interest in the
town may be mentioned the fortified _sarai_ built in the reign of Akbar,
within which is the fine tomb of Sadik Mahommed Khan (d. 1595), one of
his generals. The town, from its position on the railway, is growing in
importance as a centre of trade.

Little is known of the early history of the country forming the state of
Dholpur. Local tradition affirms that it was ruled by the Tonwar
Rajputs, who had their seat at Delhi from the 8th to the 12th century.
In 1450 it had a raja of its own; but in 1501 the fort of Dholpur was
taken by the Mahommedans under Sikandar Lodi and in 1504 was transferred
to a Mussulman governor. In 1527, after a strenuous resistance, the fort
was captured by Baber and with the surrounding country passed under the
sway of the Moguls, being included by Akbar in the province of Agra.
During the dissensions which followed the death of Aurangzeb in 1707,
Raja Kalyan Singh Bhadauria obtained possession of Dholpur, and his
family retained it till 1761, after which it was taken successively by
the Jat raja, Suraj Mal of Bharatpur, by Mirza Najaf Khan in 1775, by
Sindhia in 1782, and in 1803 by the British. It was restored to Sindhia
by the treaty of Sarji Anjangaon, but in consequence of new arrangements
was again occupied by the British. Finally, in 1806, the territories of
Dholpur, Bari and Rajakhera were handed over to the maharaj rana Kirat
Singh, ancestor of the present chiefs of Dholpur, in exchange for his
state of Gohad, which was ceded to Sindhia.

The maharaj rana of Dholpur belongs to the clan of Bamraolia Jats, who
are believed to have formed a portion of the Indo-Scythian wave of
invasion which swept over northern India about A.D. 100. An ancestor of
the family appears to have held certain territories at Bamraoli near
Agra c. 1195. His descendant in 1505, Singhan Deo, having distinguished
himself in an expedition against the freebooters of the Deccan, was
rewarded by the sovereignty of the small territory of Gohad, with the
title of _rana_. In 1779 the rana of Gohad joined the British forces
against Sindhia, under a treaty which stipulated that, at the conclusion
of peace between the English and Mahrattas, all the territories then in
his possession should be guaranteed to him, and protected from invasion
by Sindhia. This protection was subsequently withdrawn, the rana having
been guilty of treachery, and in 1783 Sindhia succeeded in recapturing
the fortress of Gwalior, and crushed his Jat opponent by seizing the
whole of Gohad. In 1804, however, the family were restored to Gohad by
the British government; but, owing to the opposition of Sindhia, the
rana agreed in 1805 to exchange Gohad for his present territory of
Dholpur, which was taken under British protection, the chief binding
himself to act in subordinate co-operation with the paramount power, and
to refer all disputes with neighbouring princes to the British
government. Kirat Singh, the first maharaj rana of Dholpur, was
succeeded in 1836 by his son Bhagwant Singh, who showed great loyalty
during the Mutiny of 1857, was created a K.C.S.I., and G.C.S.I. in 1869.
He was succeeded in 1873 by his grandson Nihal Singh, who received the
C.B. and frontier medal for services in the Tirah campaign. He died in
1901, and was succeeded by his eldest son Ram Singh (b. 1883).

  See _Imperial Gazetteer of India_ (Oxford, 1908) and authorities there
  given.


DHOW, the name given to a type of vessel used throughout the Arabian
Sea. The language to which the word belongs is unknown. According to the
_New English Dictionary_ the place of origin may be the Persian Gulf,
assuming that the word is identical with the tava mentioned by
Athanasius Nikitin (_India in the 15th Century_, Hakluyt Society, 1858).
Though the word is used generally of any craft along the East African
coast, it is usually applied to the vessel of about 150 to 200 tons
burden with a stem rising with a long slope from the water; dhows
generally have one mast with a lateen sail, the yard being of enormous
length. Much of the coasting trade of the Red Sea and Persian Gulf is
carried on by these vessels. They were the regular vessels employed in
the slave trade from the east coast of Africa.


DHRANGADRA, a native state of India, in the Gujarat division of Bombay,
situated in the north of the peninsula of Kathiawar. Its area is 1156
sq. m. Pop. (1901) 70,880. The estimated gross revenue is £38,000 and
the tribute £3000. A state railway on the metre gauge from Wadhwan to
the town of Dhrangadra, a distance of 21 m., was opened for traffic in
1898. Some cotton is grown, although the soil is as a whole poor; the
manufactures include salt, metal vessels and stone hand-mills. The chief
town, Dhrangadra, has a population (1901) of 14,770.

The chief of Dhrangadra, who bears the title of Raj Sahib, with the
predicate of His Highness, is head of the ancient clan of Jhala Rajputs,
who are said to have entered Kathiawar from Sind in the 8th century. Raj
Sahib Sir Mansinghji Ranmalsinghji (b. 1837), who succeeded his father
in 1869, was distinguished for the enlightened character of his
administration, especially in the matter of establishing schools and
internal communications. He was created a K.C.S.I in 1877. He died in
1900, and was succeeded by his grandson Ajitsinghji Jaswatsinghji (b.
1872).


DHULEEP SINGH (1837-1893), maharaja of Lahore, was born in February
1837, and was proclaimed maharaja on the 18th of September 1843, under
the regency of his mother the rani Jindan, a woman of great capacity and
strong will, but extremely inimical to the British. He was acknowledged
by Ranjit Singh and recognized by the British government. After six
years of peace the Sikhs invaded British territory in 1845, but were
defeated in four battles, and terms were imposed upon them at Lahore,
the capital of the Punjab. Dhuleep Singh retained his territory, but it
was administered to a great extent by the British government in his
name. This arrangement increased the regent's dislike of the British,
and a fresh outbreak occurred in 1848-49. In spite of the valour of the
Sikhs, they were utterly routed at Gujarat, and in March 1849 Dhuleep
Singh was deposed, a pension of £40,000 a year being granted to him and
his dependants. He became a Christian and elected to live in England. On
coming of age he made an arrangement with the British government by
which his income was reduced to £25,000 in consideration of advances for
the purchase of an estate, and he finally settled at Elvedon in Suffolk.
While passing through Alexandria in 1864 he met Miss Bamba Müller, the
daughter of a German merchant who had married an Abyssinian. The
maharaja had been interested in mission work by Sir John Login, and he
met Miss Müller at one of the missionary schools where she was teaching.
She became his wife on the 7th of June 1864, and six children were the
issue of the marriage. In the year after her death in 1890 the maharaja
married at Paris, as his second wife, an English lady, Miss Ada Douglas
Wetherill, who survived him. The maharaja was passionately fond of
sport, and his shooting parties were celebrated, while he himself became
a _persona grata_ in English society. The result, however, was financial
difficulty, and in 1882 he appealed to the government for assistance,
making various claims based upon the alleged possession of private
estates in the Punjab, and upon the surrender of the Koh-i-nor diamond
to the British Crown. His demand was rejected, whereupon he started for
India, after drawing up a proclamation to his former subjects. But as it
was deemed inadvisable to allow him to visit the Punjab, he remained for
some time as a guest at the residency at Aden, and was allowed to
receive some of his relatives to witness his abjuration of Christianity,
which actually took place within the residency itself. As the climate
began to affect his health, the maharaja at length left Aden and
returned to Europe. He stayed for some time in Russia, hoping that his
claim against England would be taken up by the Russians; but when that
expectation proved futile he proceeded to Paris, where he lived for the
rest of his life on the pension allowed him by the Indian government.
His death from an attack of apoplexy took place at Paris on the 22nd of
October 1893. The maharaja's eldest son, Prince Victor Albert Jay
Dhuleep Singh (b. 1866), was educated at Trinity and Downing Colleges,
Cambridge. In 1888 he obtained a commission in the 1st Royal Dragoon
Guards. In 1898 he married Lady Anne Coventry, youngest daughter of the
earl of Coventry.                                              (G.F.B.)


DHULIA, a town of British India, administrative headquarters of West
Khandesh district in Bombay, on the right bank of the Panjhra river.
Pop. (1901) 24,726. Considerable trade is done in cotton and oil-seeds,
and weaving of cotton. A railway connects Dhulia with Chalisgaon, on the
main line of the Great Indian Peninsula railway.


DIABASE, in petrology, a rock which is a weathered form of dolerite. It
was long widely accepted that the pre-Tertiary rocks of this group
differed from their Tertiary and Recent representatives in certain
essential respects, but this is now admitted to be untenable, and the
differences are known to be merely the result of the longer exposure to
decomposition, pressure and shearing, which the older rocks have
experienced. Their olivine tends to become serpentinized; their augite
changes to chlorite and uralite; their felspars are clouded by formation
of zeolites, calcite, sericite and epidote. The rocks acquire a green
colour (from the development of chlorite, uralite and epidote); hence
the older name of "greenstones," which is now little used. Many of them
become somewhat schistose from pressure ("greenstone-schists,"
meta-diabase, &c.). Although the original definition of the group can no
longer be justified, the name is so well established in current usage
that it can hardly be discarded. The terms diabase and dolerite are
employed really to designate distinct facies of the same set of rocks.

  The minerals of diabase are the same as those of dolerite, viz.
  olivine, augite, and plagioclase felspar, with subordinate quantities
  of hornblende, biotite, iron oxides and apatite.

  There are olivine-diabases and diabases without olivine;
  quartz-diabases, analcite-diabases (or teschenites) and hornblende
  diabases (or proterobases). Hypersthene (or bronzite) is
  characteristic of another group. Many of them are ophitic, especially
  those which contain olivine, but others are intersertal, like the
  intersertal dolerites. The last include most quartz-diabases,
  hypersthene-diabases and the rocks which have been described as
  tholeites. Porphyritic structure appears in the diabase-porphyrites,
  some of which are highly vesicular and contain remains of an abundant
  fine-grained or partly glassy ground-mass (_diabas-mandelstein_,
  amygdaloidal diabase). The somewhat ill-defined spilites are regarded
  by many as modifications of diabase-porphyrite. In the intersertal and
  porphyrite diabases, fresh or devitrified glassy base is not
  infrequent. It is especially conspicuous in some tholeites
  (hyalo-tholeites) and in weisselbergites. These rocks consist of
  augite and plagioclase, with little or no olivine, on a brown,
  vitreous, interstitial matrix. Devitrified forms of tachylyte
  (sordawilite, &c.) occur at the rapidly chilled margins of dolerite
  sills and dikes, and fine-grained spotted rocks with large spherulites
  of grey or greenish felspar, and branching growths of brownish-green
  augite (variolites).

  To nearly every variety in composition and structure presented by the
  diabases, a counterpart can be found among the Tertiary dolerites. In
  the older rocks, however, certain minerals are more common than in the
  newer. Hornblende, mostly of pale green colours and somewhat fibrous
  habit, is very frequent in diabase; it is in most cases secondary
  after pyroxene, and is then known as uralite; often it forms
  pseudomorphs which retain the shape of the original augite. Where
  diabases have been crushed or sheared, hornblende readily develops at
  the expense of pyroxene, sometimes replacing it completely. In the
  later stages of alteration the amphibole becomes compact and well
  crystallized; the rocks consist of green hornblende and plagioclase
  felspar, and are then generally known as epidiorites or amphibolites.
  At the same time a schistose structure is produced. But transition
  forms are very common, having more or less of the augite remaining,
  surrounded by newly formed hornblende which at first is rather fibrous
  and tends to spread outwards through the surrounding felspar. Chlorite
  also is abundant both in sheared and unsheared diabases, and with it
  calcite may make its appearance, or the lime set free from the augite
  may combine with the titanium of the iron oxide and with silica to
  form incrustations or borders of sphene around the original crystals
  of ilmenite. Epidote is another secondary lime-bearing mineral which
  results from the decomposition of the soda lime felspars and the
  pyroxenes. Many diabases, especially those of the teschenite
  sub-group, are filled with zeolites.

  Diabases are exceedingly abundant among the older rocks of all parts
  of the globe. Popular names for them are "whinstone," "greenstone,"
  "toadstone" and "trap." They form excellent road-mending stones and
  are much quarried for this purpose, being tough, durable and resistant
  to wear, so long as they are not extremely decomposed. Many of them
  are to be preferred to the fresher dolerites as being less brittle.
  The quality of the Cornish greenstones appears to have been distinctly
  improved by a smaller amount of recrystallization where they have been
  heated by contact with intrusive masses of granite. (J. S. F.)


DIABETES (from Gr. [Greek: dia], through, and [Greek: bainein], to
pass), a constitutional disease characterized by a habitually excessive
discharge of urine. Two forms of this complaint are described, viz.
Diabetes Mellitus, or Glycosuria, where the urine is not only increased
in quantity, but persistently contains a greater or less amount of
sugar, and Diabetes Insipidus, or Polyuria, where the urine is simply
increased in quantity, and contains no abnormal ingredient. This latter,
however, must be distinguished from the polyuria due to chronic granular
kidney, lardaceous disease of the kidney, and also occurring in certain
cases of hysteria.

_Diabetes mellitus_ is the disease to which the term is most commonly
applied, and is by far the more serious and important ailment. It is one
of the diseases due to altered metabolism (see METABOLIC DISEASES). It
is markedly hereditary, much more prevalent in towns and especially
modern city life than in more primitive rustic communities, and most
common among the Jews. The excessive use of sugar as a food is usually
considered one cause of the disease, and obesity is supposed to favour
its occurrence, but many observers consider that the obesity so often
met with among diabetics is due to the same cause as the disease itself.
No age is exempt, but it occurs most commonly in the fifth decade of
life. It attacks males twice as frequently as females, and fair more
frequently than dark people.

The symptoms are usually gradual in their onset, and the patient may
suffer for a length of time before he thinks it necessary to apply for
medical aid. The first symptoms which attract attention are failure of
strength, and emaciation, along with great thirst and an increased
amount and frequent passage of urine. From the normal quantity of from 2
to 3 pints in the 24 hours it may be increased to 10, 20 or 30 pints, or
even more. It is usually of pale colour, and of thicker consistence than
normal urine, possesses a decidedly sweet taste, and is of high specific
gravity (1030 to 1050). It frequently gives rise to considerable
irritation of the urinary passages.

By simple evaporation crystals of sugar may be obtained from diabetic
urine, which also yields the characteristic chemical tests of sugar,
while the amount of this substance can be accurately estimated by
certain analytical processes. The quantity of sugar passed may vary from
a few ounces to two or more pounds per diem, and it is found to be
markedly increased after saccharine or starchy food has been taken.
Sugar may also be found in the blood, saliva, tears, and in almost all
the excretions of persons suffering from this disease. One of the most
distressing symptoms is intense thirst, which the patient is constantly
seeking to allay, the quantity of liquid consumed being in general
enormous, and there is usually, but not invariably, a voracious
appetite. The mouth is always parched, and a faint, sweetish odour may
be evolved from the breath. The effect of the disease upon the general
health is very marked, and the patient becomes more and more emaciated.
He suffers from increasing muscular weakness, the temperature of his
body is lowered, and the skin is dry and harsh. There is often a
peculiar flush on the face, not limited to the malar eminences, but
extending up to the roots of the hair. The teeth are loosened or decay,
there is a tendency to bleeding from the gums, while dyspeptic symptoms,
constipation and loss of sexual power are common accompaniments. There
is in general great mental depression or irritability.

Diabetes as a rule advances comparatively slowly except in the case of
young persons, in whom its progress is apt to be rapid. The
complications of the disease are many and serious. It may cause impaired
vision by weakening the muscles of accommodation, or by lessening the
sensitiveness of the retina to light. Also cataract is very common. Skin
affections of all kinds may occur and prove very intractable. Boils,
carbuncles, cellulitis and gangrene are all apt to occur as life
advances, though gangrene is much more frequent in men than in women.
Diabetics are especially liable to phthisis and pneumonia, and gangrene
of the lungs may set in if the patient survives the crisis in the latter
disease. Digestive troubles of all kinds, kidney diseases and heart
failure due to fatty heart are all of common occurrence. Also patients
seem curiously susceptible to the poison of enteric fever, though the
attack usually runs a mild course. The sugar temporarily disappears
during the fever. But the most serious complication of all is known as
diabetic coma, which is very commonly the final cause of death. The
onset is often insidious, but may be indicated by loss of appetite, a
rapid fall in the quantity of both urine and sugar, and by either
constipation or diarrhoea. More rarely there is most acute abdominal
pain. At first the condition is rather that of collapse than true coma,
though later the patient is absolutely comatose. The patient suffers
from a peculiar kind of dyspnoea, and the breath and skin have a sweet
ethereal odour. The condition may last from twenty-four hours to three
days, but is almost invariably the precursor of death.

Diabetes is a very fatal form of disease, recovery being exceedingly
rare. Over 50% die of coma, another 25% of phthisis or pneumonia, and
the remainder of Bright's disease, cerebral haemorrhage, gangrene, &c.
The most favourable cases are those in which the patient is advanced in
years, those in which it is associated with obesity or gout, and where
the social conditions are favourable. A few cures have been recorded in
which the disease supervened after some acute illness. The unfavourable
cases are those in which there is a family history of the disease and in
which the patient is young. Nevertheless much may be done by appropriate
treatment to mitigate the severity of the symptoms and to prolong life.

There are two distinct lines of treatment, that of diet and that of
drugs, but each must be modified and determined entirely by the
idiosyncrasy of the patient, which varies in this condition between very
wide limits. That of diet is of primary importance inasmuch as it has
been proved beyond question that certain kinds of food have a powerful
influence in aggravating the disease, more particularly those consisting
largely of saccharine and starchy matter; and it may be stated generally
that the various methods of treatment proposed aim at the elimination as
far as possible of these constituents from the diet. Hence it is
recommended that such articles as bread, potatoes and all farinaceous
foods, turnips, carrots, parsnips and most fruits should be avoided;
while animal food and soups, green vegetables, cream, cheese, eggs,
butter, and tea and coffee without sugar, may be taken with advantage.
As a substitute for ordinary bread, which most persons find it difficult
to do without for any length of time, bran bread, gluten bread and
almond biscuits. A patient must never pass suddenly from an ordinary to
a carbohydrate-free diet. Any such sudden transition is extremely liable
to bring on diabetic coma, and the change must be made quite gradually,
one form of carbohydrate after another being taken out of the diet,
whilst the effect on the quantity of sugar passed is being carefully
noted meanwhile. The treatment may be begun by excluding potatoes, sugar
and fruit, and only after several days is the bread to be replaced by
some diabetic substitute. When the sugar excretion has been reduced to
its lowest point, and maintained there for some time, a certain amount
of carbohydrate may be cautiously allowed, the consequent effect on the
glycosuria being estimated. The best diet can only be worked out
experimentally for each individual patient. But in every case, if
drowsiness or any symptom suggesting coma supervene, all restrictions
must be withdrawn, and carbohydrate freely allowed. The question of
alcohol is one which must be largely determined by the previous history
of the patient, but a small quantity will help to make up the
deficiencies of a diet poor in carbohydrate. Scotch and Irish whisky,
and Hollands gin, are usually free from sugar, and some of the light
Bordeaux wines contain very little. Fat is beneficial, and can be given
as cream, fat of meat and cod-liver oil. Green vegetables are harmless,
but the white stalks of cabbages and lettuces and also celery and endive
yield sugar. Laevulose can be assimilated up to 1½ ozs. daily without
increasing the glycosuria, and hence apples, cooked or raw, are
allowable, as the sugar they contain is in this form. The question of
milk is somewhat disputed; but it is usual to exclude it from the rigid
diet, allowing a certain quantity when the diet is being extended.
Thirst is relieved by anything that relieves the polyuria. But
hypodermic injections of pilocarpine stimulate the flow of saliva, and
thus relieve the dryness of the mouth. Constipation appears to increase
the thirst, and must always be carefully guarded against. The best
remedies are the aperient mineral waters.

Numerous medicinal substances have been employed in diabetes, but few of
them are worthy of mention as possessed of any efficacy. Opium is often
found of great service, its administration being followed by marked
amelioration in all the symptoms. Morphia and codeia have a similar
action. In the severest cases, however, these drugs appear to be of
little or no use, and they certainly increase the constipation. Heroin
hydrochloride has been tried in their place, but this seems to have more
power over slight than over severe cases. Salicylate of sodium and
aspirin are both very beneficial, causing a diminution in the sugar
excretion without counterbalancing bad effects.

In _diabetes insipidus_ there is constant thirst and an excessive flow
of urine, which, however, is not found to contain any abnormal
constituent. Its effects upon the system are often similar to those of
diabetes mellitus, except that they are much less marked, the disease
being in general very slow in its progress. In some cases the health
appears to suffer very slightly. It is rarely a direct cause of death,
but from its debilitating effects may predispose to serious and fatal
complications. It is best treated by tonics and generous diet. Valerian
has been found beneficial, the powdered root being given in 5-grain
doses.


DIABOLO, a game played with a sort of top in the shape of two cones
joined at their apices, which is spun, thrown, and caught by means of a
cord strung to two sticks. The idea of the game appears originally to
have come from China, where a top (_Kouengen_), made of two hollow
pierced cylinders of metal or wood, joined by a rod--and often of
immense size,--was made by rotation to hum with a loud noise, and was
used by pedlars to attract customers. From China it was introduced by
missionaries to Europe; and a form of the game, known as "the devil on
two sticks," appears to have been known in England towards the end of
the 18th century, and Lord Macartney is credited with improvements in
it. But its principal vogue was in France in 1812, where the top was
called "le diable." Amusing old prints exist (see _Fry's Magazine_,
March and December 1907), depicting examples of the popular craze in
France at the time. The _diable_ of those days resembled a globular
wooden dumb-bell with a short waist, and the sonorous hum when
spinning--the _bruit du diable_--was a pronounced feature. At intervals
during the century occasional attempts to revive the game of spinning a
top of this sort on a string were made, but it was not till 1906 that
the sensation of 1812 began to be repeated. A French engineer, Gustave
Phillipart, discovering some old implements of the game, had
experimented for some time with new forms of top with a view to bringing
it again into popularity; and having devised the double-cone shape, and
added a miniature bicycle tire of rubber round the rims of the two ends
of the double-cone, with other improvements, he named it "diabolo." The
use of celluloid in preference to metal or wood as its material appears
to have been due to a suggestion of Mr C. B. Fry, who was consulted by
the inventor on the subject. The game of spinning, throwing and catching
the diabolo was rapidly elaborated in various directions, both as an
exercise of skill in doing tricks, and in "diabolo tennis" and other
ways as an athletic pastime. From Paris, Ostend and the chief French
seaside resorts, where it became popular in 1906, its vogue spread in
1907 so that in France and England it became the fashionable "rage"
among both children and adults.

The mechanics of the diabolo were worked out by Professor C. V. Boys in
the _Proc. Phys. Soc._ (London), Nov. 1907.


DIACONICON, in the Greek Church, the name given to a chamber on the
south side of the central apse, where the sacred utensils, vessels, &c.,
of the church were kept. In the reign of Justin II. (565-574), owing to
a change in the liturgy, the diaconicon and protheses were located in
apses at the east end of the aisles. Before that time there was only one
apse. In the churches in central Syria of slightly earlier date, the
diaconicon is rectangular, the side apses at Kalat-Seman having been
added at a later date.


DIADOCHI (Gr. [Greek: diadechesthai], to receive from another), i.e.
"Successors," the name given to the Macedonian generals who fought for
the empire of Alexander after his death in 323 B.C. The name includes
Antigonus and his son Demetrius Poliorcetes, Antipater and his son
Cassander, Seleucus, Ptolemy, Eumenes and Lysimachus. The kingdoms into
which the Macedonian empire was divided under these rulers are known as
Hellenistic. The chief were Asia Minor and Syria under the SELEUCID
DYNASTY (q.v.), Egypt under the PTOLEMIES (q.v.), Macedonia under the
successors of Antigonus Gonatas, PERGAMUM (q.v.) under the Attalid
dynasty. Gradually these kingdoms were merged in the Roman empire. (See
MACEDONIAN EMPIRE.)


DIAGONAL (Gr. [Greek: dia], through, [Greek: gônia], a corner), in
geometry, a line joining the intersections of two pairs of sides of a
rectilinear figure.


DIAGORAS, of Melos, surnamed the Atheist, poet and sophist, flourished
in the second half of the 5th century B.C. Religious in his youth and a
writer of hymns and dithyrambs, he became an atheist because a great
wrong done to him was left unpunished by the gods. In consequence of his
blasphemous speeches, and especially his criticism of the Mysteries, he
was condemned to death at Athens, and a price set upon his head
(Aristoph. _Clouds_, 830; _Birds_, 1073 and Schol.). He fled to Corinth,
where he is said to have died. His work on the Mysteries was called
[Greek Phrygioi logoi] or [Greek: Apopyrgizontes], in which he probably
attacked the Phrygian divinities.


DIAGRAM (Gr. [Greek: diagramma], from [Greek: diagraphein], to mark out
by lines), a figure drawn in such a manner that the geometrical relations
between the parts of the figure illustrate relations between other
objects. They may be classed according to the manner in which they are
intended to be used, and also according to the kind of analogy which we
recognize between the diagram and the thing represented. The diagrams in
mathematical treatises are intended to help the reader to follow the
mathematical reasoning. The construction of the figure is defined in
words so that even if no figure were drawn the reader could draw one for
himself. The diagram is a good one if those features which form the
subject of the proposition are clearly represented.

Diagrams are also employed in an entirely different way--namely, for
purposes of measurement. The plans and designs drawn by architects and
engineers are used to determine the value of certain real magnitudes by
measuring certain distances on the diagram. For such purposes it is
essential that the drawing be as accurate as possible. We therefore
class diagrams as diagrams of illustration, which merely suggest certain
relations to the mind of the spectator, and diagrams drawn to scale,
from which measurements are intended to be made. There are some diagrams
or schemes, however, in which the form of the parts is of no importance,
provided their connexions are properly shown. Of this kind are the
diagrams of electrical connexions, and those belonging to that
department of geometry which treats of the degrees of cyclosis,
periphraxy, linkedness and knottedness.

_Diagrams purely Graphic and mixed Symbolic and Graphic._--Diagrams may
also be classed either as purely graphical diagrams, in which no symbols
are employed except letters or other marks to distinguish particular
points of the diagrams, and mixed diagrams, in which certain magnitudes
are represented, not by the magnitudes of parts of the diagram, but by
symbols, such as numbers written on the diagram. Thus in a map the
height of places above the level of the sea is often indicated by
marking the number of feet above the sea at the corresponding places on
the map. There is another method in which a line called a contour line
is drawn through all the places in the map whose height above the sea is
a certain number of feet, and the number of feet is written at some
point or points of this line. By the use of a series of contour lines,
the height of a great number of places can be indicated on a map by
means of a small number of written symbols. Still this method is not a
purely graphical method, but a partly symbolical method of expressing
the third dimension of objects on a diagram in two dimensions.

In order to express completely by a purely graphical method the
relations of magnitudes involving more than two variables, we must use
more than one diagram. Thus in the arts of construction we use plans and
elevations and sections through different planes, to specify the form of
objects having three dimensions. In such systems of diagrams we have to
indicate that a point in one diagram corresponds to a point in another
diagram. This is generally done by marking the corresponding points in
the different diagrams with the same letter. If the diagrams are drawn
on the same piece of paper we may indicate corresponding points by
drawing a line from one to the other, taking care that this line of
correspondence is so drawn that it cannot be mistaken for a real line in
either diagram. (See GEOMETRY: _Descriptive_.)

In the stereoscope the two diagrams, by the combined use of which the
form of bodies in three dimensions is recognized, are projections of the
bodies taken from two points so near each other that, by viewing the two
diagrams simultaneously, one with each eye, we identify the
corresponding points intuitively. The method in which we simultaneously
contemplate two figures, and recognize a correspondence between certain
points in the one figure and certain points in the other, is one of the
most powerful and fertile methods hitherto known in science. Thus in
pure geometry the theories of similar, reciprocal and inverse figures
have led to many extensions of the science. It is sometimes spoken of as
the method or principle of Duality. GEOMETRY: _Projective_.)

                        DIAGRAMS IN MECHANICS.

  The study of the motion of a material system is much assisted by the
  use of a series of diagrams representing the configuration,
  displacement and acceleration of the parts of the system.

  _Diagram of Configuration._--In considering a material system it is
  often convenient to suppose that we have a record of its position at
  any given instant in the form of a diagram of configuration. The
  position of any particle of the system is defined by drawing a
  straight line or vector from the origin, or point of reference, to the
  given particle. The position of the particle with respect to the
  origin is determined by the magnitude and direction of this vector. If
  in the diagram we draw from the origin (which need not be the same
  point of space as the origin for the material system) a vector equal
  and parallel to the vector which determines the position of the
  particle, the end of this vector will indicate the position of the
  particle in the diagram of configuration. If this is done for all the
  particles we shall have a system of points in the diagram of
  configuration, each of which corresponds to a particle of the material
  system, and the relative positions of any pair of these points will be
  the same as the relative positions of the material particles which
  correspond to them.

  We have hitherto spoken of two origins or points from which the
  vectors are supposed to be drawn--one for the material system, the
  other for the diagram. These points, however, and the vectors drawn
  from them, may now be omitted, so that we have on the one hand the
  material system and on the other a set of points, each point
  corresponding to a particle of the system, and the whole representing
  the configuration of the system at a given instant.

  This is called a diagram of configuration.

  _Diagram of Displacement._--Let us next consider two diagrams of
  configuration of the same system, corresponding to two different
  instants. We call the first the initial configuration and the second
  the final configuration, and the passage from the one configuration to
  the other we call the displacement of the system. We do not at present
  consider the length of time during which the displacement was
  effected, nor the intermediate stages through which it passed, but
  only the final result--a change of configuration. To study this change
  we construct a diagram of displacement.

  Let A, B, C be the points in the initial diagram of configuration, and
  A', B', C' be the corresponding points in the final diagram of
  configuration. From o, the origin of the diagram of displacement, draw
  a vector oa equal and parallel to AA', ob equal and parallel to BB',
  oc to CC', and so on. The points a, b, c, &c., will be such that the
  vector ab indicates the displacement of B relative to A, and so on.
  The diagram containing the points a, b, c, &c., is therefore called
  the diagram of displacement.

  In constructing the diagram of displacement we have hitherto assumed
  that we know the absolute displacements of the points of the system.
  For we are required to draw a line equal and parallel to AA', which we
  cannot do unless we know the absolute final position of A, with
  respect to its initial position. In this diagram of displacement there
  is therefore, besides the points a, b, c, &c., an _origin_, o, which
  represents a point absolutely fixed in space. This is necessary
  because the two configurations do not exist at the same time; and
  therefore to express their relative position we require to know a
  point which remains the same at the beginning and end of the time.

  But we may construct the diagram in another way which does not assume
  a knowledge of absolute displacement or of a point fixed in space.
  Assuming any point and calling it a, draw ak parallel and equal to BA
  in the initial configuration, and from k draw kb parallel and equal to
  A'B' in the final configuration. It is easy to see that the position
  of the point b relative to a will be the same by this construction as
  by the former construction, only we must observe that in this second
  construction we use only vectors such as AB, A'B', which represent the
  relative position of points both of which exist simultaneously,
  instead of vectors such as AA', BB', which express the position of a
  point at one instant relative to its position at a former instant, and
  which therefore cannot be determined by observation, because the two
  ends of the vector do not exist simultaneously.

  It appears therefore that the diagram of displacements, when drawn by
  the first construction, includes an origin o, which indicates that we
  have assumed a knowledge of absolute displacements. But no such point
  occurs in the second construction, because we use such vectors only as
  we can actually observe. Hence the diagram of displacements _without
  an origin_ represents neither more nor less than all we can ever know
  about the displacement of the material system.

  _Diagram of Velocity._--If the relative velocities of the points of
  the system are constant, then the diagram of displacement
  corresponding to an interval of a unit of time between the initial and
  the final configuration is called a diagram of relative velocity. If
  the relative velocities are not constant, we suppose another system in
  which the velocities are equal to the velocities of the given system
  at the given instant and continue constant for a unit of time. The
  diagram of displacements for this imaginary system is the required
  diagram of relative velocities of the actual system at the given
  instant. It is easy to see that the diagram gives the velocity of any
  one point relative to any other, but cannot give the absolute velocity
  of any of them.

  _Diagram of Acceleration._--By the same process by which we formed the
  diagram of displacements from the two diagrams of initial and final
  configuration, we may form a diagram of changes of relative velocity
  from the two diagrams of initial and final velocities. This diagram
  may be called that of total accelerations in a finite interval of
  time. And by the same process by which we deduced the diagram of
  velocities from that of displacements we may deduce the diagram of
  rates of acceleration from that of total acceleration.

  We have mentioned this system of diagrams in elementary kinematics
  because they are found to be of use especially when we have to deal
  with material systems containing a great number of parts, as in the
  kinetic theory of gases. The diagram of configuration then appears as
  a region of space swarming with points representing molecules, and the
  only way in which we can investigate it is by considering the number
  of such points in unit of volume in different parts of that region,
  and calling this the _density_ of the gas.

  In like manner the diagram of velocities appears as a region
  containing points equal in number but distributed in a different
  manner, and the number of points in any given portion of the region
  expresses the number of molecules whose velocities lie within given
  limits. We may speak of this as the velocity-density.

  _Diagrams of Stress._--Graphical methods are peculiarly applicable to
  statical questions, because the state of the system is constant, so
  that we do not need to construct a series of diagrams corresponding to
  the successive states of the system. The most useful of these
  applications, collectively termed Graphic Statics, relates to the
  equilibrium of plane framed structures familiarly represented in
  bridges and roof-trusses. Two diagrams are used, one called the
  diagram of the frame and the other called the diagram of stress. The
  structure itself consists of a number of separable pieces or links
  jointed together at their extremities. In practice these joints have
  friction, or may be made purposely stiff, so that the force acting at
  the extremity of a piece may not pass exactly through the axis of the
  joint; but as it is unsafe to make the stability of the structure
  depend in any degree upon the stiffness of joints, we assume in our
  calculations that all the joints are perfectly smooth, and therefore
  that the force acting on the end of any link passes through the axis
  of the joint.

  The axes of the joints of the structure are represented by points in
  the diagram of the frame. The link which connects two joints in the
  actual structure may be of any shape, but in the diagram of the frame
  it is represented by a straight line joining the points representing
  the two joints. If no force acts on the link except the two forces
  acting through the centres of the joints, these two forces must be
  equal and opposite, and their direction must coincide with the
  straight line joining the centres of the joints. If the force acting
  on either extremity of the link is directed towards the other
  extremity, the stress on the link is called pressure and the link is
  called a "strut." If it is directed away from the other extremity, the
  stress on the link is called tension and the link is called a "tie."
  In this case, therefore, the only stress acting in a link is a
  pressure or a tension in the direction of the straight line which
  represents it in the diagram of the frame, and all that we have to do
  is to find the magnitude of this stress. In the actual structure
  gravity acts on every part of the link, but in the diagram we
  substitute for the actual weight of the different parts of the link
  two weights which have the same resultant acting at the extremities of
  the link.

  We may now treat the diagram of the frame as composed of links without
  weight, but loaded at each joint with a weight made up of portions of
  the weights of all the links which meet in that joint. If any link has
  more than two joints we may substitute for it in the diagram an
  imaginary stiff frame, consisting of links, each of which has only two
  joints. The diagram of the frame is now reduced to a system of points,
  certain pairs of which are joined by straight lines, and each point is
  in general acted on by a weight or other force acting between it and
  some point external to the system. To complete the diagram we may
  represent these external forces as links, that is to say, straight
  lines joining the points of the frame to points external to the frame.
  Thus each weight may be represented by a link joining the point of
  application of the weight with the centre of the earth.

  But we can always construct an imaginary frame having its joints in
  the lines of action of these external forces, and this frame, together
  with the real frame and the links representing external forces, which
  join points in the one frame to points in the other frame, make up
  together a complete self-strained system in equilibrium, consisting of
  points connected by links acting by pressure or tension. We may in
  this way reduce any real structure to the case of a system of points
  with attractive or repulsive forces acting between certain pairs of
  these points, and keeping them in equilibrium. The direction of each
  of these forces is sufficiently indicated by that of the line joining
  the points, so that we have only to determine its magnitude. We might
  do this by calculation, and then write down on each link the pressure
  or the tension which acts in it.

  We should in this way obtain a mixed diagram in which the stresses are
  represented graphically as regards direction and position, but
  symbolically as regards magnitude. But we know that a force may be
  represented in a purely graphical manner by a straight line in the
  direction of the force containing as many units of length as there are
  units of force in the force. The end of this line is marked with an
  arrow head to show in which direction the force acts. According to
  this method each force is drawn in its proper position in the diagram
  of configuration of the frame. Such a diagram might be useful as a
  record of the result of calculation of the magnitude of the forces,
  but it would be of no use in enabling us to test the correctness of
  the calculation.

  But we have a graphical method of testing the equilibrium of any set
  of forces acting at a point. We draw in series a set of lines parallel
  and proportional to these forces. If these lines form a closed polygon
  the forces are in equilibrium. (See MECHANICS.) We might in this way
  form a series of polygons of forces, one for each joint of the frame.
  But in so doing we give up the principle of drawing the line
  representing a force from the point of application of the force, for
  all the sides of the polygon cannot pass through the same point, as
  the forces do. We also represent every stress twice over, for it
  appears as a side of both the polygons corresponding to the two joints
  between which it acts. But if we can arrange the polygons in such a
  way that the sides of any two polygons which represent the same stress
  coincide with each other, we may form a diagram in which every stress
  is represented in direction and magnitude, though not in position, by
  a single line which is the common boundary of the two polygons which
  represent the joints at the extremities of the corresponding piece of
  the frame.

  We have thus obtained a pure diagram of stress in which no attempt is
  made to represent the configuration of the material system, and in
  which every force is not only represented in direction and magnitude
  by a straight line, but the equilibrium of the forces at any joint is
  manifest by inspection, for we have only to examine whether the
  corresponding polygon is closed or not.

  The relations between the diagram of the frame and the diagram of
  stress are as follows:--To every link in the frame corresponds a
  straight line in the diagram of stress which represents in magnitude
  and direction the stress acting in that link; and to every joint of
  the frame corresponds a closed polygon in the diagram, and the forces
  acting at that joint are represented by the sides of the polygon taken
  in a certain cyclical order, the cyclical order of the sides of the
  two adjacent polygons being such that their common side is traced in
  opposite directions in going round the two polygons.

  The direction in which any side of a polygon is traced is the
  direction of the force acting on that joint of the frame which
  corresponds to the polygon, and due to that link of the frame which
  corresponds to the side. This determines whether the stress of the
  link is a pressure or a tension. If we know whether the stress of any
  one link is a pressure or a tension, this determines the cyclical
  order of the sides of the two polygons corresponding to the ends of
  the links, and therefore the cyclical order of all the polygons, and
  the nature of the stress in every link of the frame.

  _Reciprocal Diagrams._--When to every point of concourse of the lines
  in the diagram of stress corresponds a closed polygon in the skeleton
  of the frame, the two diagrams are said to be reciprocal.

  The first extensions of the method of diagrams of forces to other
  cases than that of the funicular polygon were given by Rankine in his
  _Applied Mechanics_ (1857). The method was independently applied to a
  large number of cases by W. P. Taylor, a practical draughtsman in the
  office of J. B. Cochrane, and by Professor Clerk Maxwell in his
  lectures in King's College, London. In the _Phil. Mag._ for 1864 the
  latter pointed out the reciprocal properties of the two diagrams, and
  in a paper on "Reciprocal Figures, Frames and Diagrams of Forces,"
  _Trans. R.S. Edin._ vol. xxvi., 1870, he showed the relation of the
  method to Airy's function of stress and to other mathematical methods.
  Professor Fleeming Jenkin has given a number of applications of the
  method to practice (_Trans. R.S. Edin._ vol. xxv.).

  L. Cremona (_Le Figure reciproche nella statica grafica_, 1872)
  deduced the construction of reciprocal figures from the theory of the
  two components of a wrench as developed by Möbius. Karl Culmann, in
  his _Graphische Statik_ (1st ed. 1864-1866, 2nd ed. 1875), made great
  use of diagrams of forces, some of which, however, are not
  reciprocal. Maurice Levy in his _Statique graphique_ (1874) has
  treated the whole subject in an elementary but copious manner, and R.
  H. Bow, in his _The Economics of Construction in Relation to Framed
  Structures_ (1873), materially simplified the process of drawing a
  diagram of stress reciprocal to a given frame acted on by a system of
  equilibrating external forces.

  [Illustration: FIG. 1.--Diagram of Configuration.]

  Instead of lettering the joints of the frame, as is usually done, or
  the links of the frame, as was the custom of Clerk Maxwell, Bow places
  a letter in each of the polygonal areas enclosed by the links of the
  frame, and also in each of the divisions of surrounding space as
  separated by the lines of action of the external forces. When one link
  of the frame crosses another, the point of apparent intersection of
  the links is treated as if it were a real joint, and the stresses of
  each of the intersecting links are represented twice in the diagram of
  stress, as the opposite sides of the parallelogram which corresponds
  to the point of intersection.

  This method is followed in the lettering of the diagram of
  configuration (fig. 1), and the diagram of stress (fig. 2) of the
  linkwork which Professor Sylvester has called a quadruplane.

  In fig. 1 the real joints are distinguished from the places where one
  link appears to cross another by the little circles O, P, Q, R, S, T,
  V. The four links RSTV form a "contraparallelogram" in which RS = TV
  and RV = ST. The triangles ROS, RPV, TQS are similar to each other. A
  fourth triangle (TNV), not drawn in the figure, would complete the
  quadruplane. The four points O, P, N, Q form a parallelogram whose
  angle POQ is constant and equal to [pi] - SOR. The product of the
  distances OP and OQ is constant. The linkwork may be fixed at O. If
  any figure is traced by P, Q will trace the inverse figure, but turned
  round O through the constant angle POQ. In the diagram forces Pp, Qq
  are balanced by the force Co at the fixed point. The forces Pp and Qq
  are necessarily inversely as OP and OQ, and make equal angles with
  those lines.

  [Illustration: Fig. 2.--Diagram of Stress.]

  Every closed area formed by the links or the external forces in the
  diagram of configuration is marked by a letter which corresponds to a
  point of concourse of lines in the diagram of stress. The stress in
  the link which is the common boundary of two areas is represented in
  the diagram of stress by the line joining the points corresponding to
  those areas. When a link is divided into two or more parts by lines
  crossing it, the stress in each part is represented by a different
  line for each part, but as the stress is the same throughout the link
  these lines are all equal and parallel. Thus in the figure the stress
  in RV is represented by the four equal and parallel lines HI, FG, DE
  and AB. If two areas have no part of their boundary in common the
  letters corresponding to them in the diagram of stress are not joined
  by a straight line. If, however, a straight line were drawn between
  them, it would represent in direction and magnitude the resultant of
  all the stresses in the links which are cut by any line, straight or
  curved, joining the two areas. For instance the areas F and C in fig.
  1 have no common boundary, and the points F and C in fig. 2 are not
  joined by a straight line. But every path from the area F to the area
  C in fig. 1 passes through a series of other areas, and each passage
  from one area into a contiguous area corresponds to a line drawn in
  the diagram of stress. Hence the whole path from F to C in fig. 1
  corresponds to a path formed of lines in fig. 2 and extending from F
  to C, and the resultant of all the stresses in the links cut by the
  path is represented by FC in fig. 2.

  Many examples of stress diagrams are given in the article on BRIDGES
  (q.v.).

                 _Automatic Description of Diagrams._

  There are many other kinds of diagrams in which the two co-ordinates
  of a point in a plane are employed to indicate the simultaneous values
  of two related quantities. If a sheet of paper is made to move, say
  horizontally, with a constant known velocity, while a tracing point is
  made to move in a vertical straight line, the height varying as the
  value of any given physical quantity, the point will trace out a curve
  on the paper from which the value of that quantity at any given time
  may be determined. This principle is applied to the automatic
  registration of phenomena of all kinds, from those of meteorology and
  terrestrial magnetism to the velocity of cannon-shot, the vibrations
  of sounding bodies, the motions of animals, voluntary and involuntary,
  and the currents in electric telegraphs.

  In Watt's indicator for steam engines the paper does not move with a
  constant velocity, but its displacement is proportional to that of the
  piston of the engine, while that of the tracing point is proportional
  to the pressure of the steam. Hence the co-ordinates of a point of the
  curve traced on the diagram represent the volume and the pressure of
  the steam in the cylinder. The indicator-diagram not only supplies a
  record of the pressure of the steam at each stage of the stroke of the
  engine, but indicates the work done by the steam in each stroke by the
  area enclosed by the curve traced on the diagram.          (J. C. M.)


DIAL and DIALLING. Dialling, sometimes called gnomonics, is a branch of
applied mathematics which treats of the construction of sun-dials, that
is, of those instruments, either fixed or portable, which determine the
divisions of the day (Lat. _dies_) by the motion of the shadow of some
object on which the sun's rays fall. It must have been one of the
earliest applications of a knowledge of the apparent motion of the sun;
though for a long time men would probably be satisfied with the division
into morning and afternoon as marked by sun-rise, sun-set and the
greatest elevation.

_History._--The earliest mention of a sun-dial is found in Isaiah
xxxviii. 8: "Behold, I will bring again the shadow of the degrees which
is gone down in the _sun-dial_ of Ahaz ten degrees backward." The date
of this would be about 700 years before the Christian era, but we know
nothing of the character or construction of the instrument. The earliest
of all sun-dials of which we have any certain knowledge was the
hemicycle, or hemisphere, of the Chaldaean astronomer Berossus, who
probably lived about 300 B.C. It consisted of a hollow hemisphere placed
with its rim perfectly horizontal, and having a bead, or globule, fixed
in any way at the centre. So long as the sun remained above the horizon
the shadow of the bead would fall on the inside of the hemisphere, and
the path of the shadow during the day would be approximately a circular
arc. This arc, divided into twelve equal parts, determined twelve equal
intervals of time for that day. Now, supposing this were done at the
time of the solstices and equinoxes, and on as many intermediate days as
might be considered sufficient, and then curve lines drawn through the
corresponding points of division of the different arcs, the shadow of
the bead falling on one of these curve lines would mark a division of
time for that day, and thus we should have a sun-dial which would divide
each period of daylight into twelve equal parts. These equal parts were
called _temporary hours_; and, since the duration of daylight varies
from day to day, the temporary hours of one day would differ from those
of another; but this inequality would probably be disregarded at that
time, and especially in countries where the variation between the
longest summer day and the shortest winter day is much less than in our
climates.

The dial of Berossus remained in use for centuries. The Arabians, as
appears from the work of Albategnius, still followed the same
construction about the year A.D. 900. Four of these dials have in modern
times been found in Italy. One, discovered at Tivoli in 1746, is
supposed to have belonged to Cicero, who, in one of his letters, says
that he had sent a dial of this kind to his villa near Tusculum. The
second and third were found in 1751--one at Castel-Nuovo and the other
at Rignano; and a fourth was found in 1762 at Pompeii. G. H. Martini in
his _Abhandlungen von den Sonnenuhren der Alten_ (Leipzig, 1777), says
that this dial was made for the latitude of Memphis; it may therefore
be the work of Egyptians, perhaps constructed in the school of
Alexandria.

Herodotus recorded that the Greeks derived from the Babylonians the use
of the gnomon, but the great progress made by the Greeks in geometry
enabled them in later times to construct dials of great complexity, some
of which remain to us, and are proof not only of extensive knowledge but
also of great ingenuity.

Ptolemy's _Almagest_ treats of the construction of dials by means of his
_analemma_, an instrument which solved a variety of astronomical
problems. The constructions given by him were sufficient for regular
dials, that is, horizontal dials, or vertical dials facing east, west,
north or south, and these are the only ones he treats of. It is certain,
however, that the ancients were able to construct declining dials, as is
shown by that most interesting monument of ancient gnomics--the Tower of
the Winds at Athens. This is a regular octagon, on the faces of which
the eight principal winds are represented, and over them eight different
dials--four facing the cardinal points and the other four facing the
intermediate directions. The date of the dials is long subsequent to
that of the tower; for Vitruvius, who describes the tower in the sixth
chapter of his first book, says nothing about the dials, and as he has
described all the dials known in his time, we must believe that the
dials of the tower did not then exist. The hours are still the temporary
hours or, as the Greeks called them, _hectemoria_.

The first sun-dial erected at Rome was in the year 290 B.C., and this
Papirius Cursor had taken from the Samnites. A dial which Valerius
Messalla had brought from Catania, the latitude of which is five degrees
less than that of Rome, was placed in the forum in the year 261 B.C. The
first dial actually constructed at Rome was in the year 164 B.C., by
order of Q. Marcius Philippus, but as no other Roman has written on
gnomonics, this was perhaps the work of a foreign artist. If, too, we
remember that the dial found at Pompeii was made for the latitude of
Memphis, and consequently less adapted to its position than that of
Catania to Rome, we may infer that mathematical knowledge was not
cultivated in Italy.

The Arabians were much more successful. They attached great importance
to gnomonics, the principles of which they had learned from the Greeks,
but they greatly simplified and diversified the Greek constructions. One
of their writers, Abu'l Hassan, who lived about the beginning of the
13th century, taught them how to trace dials on cylindrical, conical and
other surfaces. He even introduced _equal_ or _equinoctial hours_, but
the idea was not supported, and the temporary hours alone continued in
use.

Where or when the great and important step already conceived by Abu'l
Hassan, and perhaps by others, of reckoning by _equal_ hours was
generally adopted cannot now be determined. The history of gnomonics
from the 13th to the beginning of the 16th century is almost a blank,
and during that time the change took place. We can see, however, that
the change would necessarily follow the introduction of clocks and other
mechanical methods of measuring time; for, however imperfect these were,
the hours they marked would be of the same length in summer and in
winter, and the discrepancy between these equal hours and the temporary
hours of the sun-dial would soon be too important to be overlooked. Now,
we know that a balance clock was put up in the palace of Charles V. of
France about the year 1370, and we may reasonably suppose that the new
sun-dials came into general use during the 14th and 15th centuries.

Among the earliest of the modern writers on gnomonics was SEBASTIAN
MÜNSTER (q.v.), who published his _Horologiographia_ at Basel in 1531.
He gives a number of correct rules, but without demonstrations. Among
his inventions was a moon-dial,[1] but this does not admit of much
accuracy.

During the 17th century dialling was discussed at great length by many
writers on astronomy. Clavius devotes a quarto volume of 800 pages
entirely to the subject. This was published in 1612, and may be
considered to contain all that was known at that time.

In the 18th century clocks and watches began to supersede sun-dials, and
these have gradually fallen into disuse except as an additional ornament
to a garden, or in remote country districts where the old dial on the
church tower still serves as an occasional check on the modern clock by
its side. The art of constructing dials may now be looked upon as little
more than a mathematical recreation.

  _General Principles._--The diurnal and the annual motions of the earth
  are the elementary astronomical facts on which dialling is founded.
  That the earth turns upon its axis uniformly from west to east in
  twenty-four hours, and that it is carried round the sun in one year at
  a nearly uniform rate, is the correct way of expressing these facts.
  But the effect will be precisely the same, and it will suit our
  purpose better, and make our explanations easier, if we adopt the
  ideas of the ancients, of which our senses furnish apparent
  confirmation, and assume the earth to be fixed. Then, the sun and
  stars revolve round the earth's axis uniformly from east to west once
  a day--the sun lagging a little behind the stars, making its day some
  four minutes longer--so that at the end of the year it finds itself
  again in the same place, having made a complete revolution of the
  heavens relatively to the stars from west to east.

  The fixed axis about which all these bodies revolve daily is a line
  through the earth's centre; but the radius of the earth is so small,
  compared with the enormous distance of the sun, that, if we draw a
  parallel axis through any point of the earth's surface, we may safely
  look on that as being the axis of the celestial motions. The error in
  the case of the sun would not, at its maximum, that is, at 6 A.M. and
  6 P.M., exceed half a second of time, and at noon would vanish. An
  axis so drawn is in the plane of the meridian, and points to the pole,
  its elevation being equal to the latitude of the place.

  The diurnal motion of the stars is strictly uniform, and so would that
  of the sun be if the daily retardation of about four minutes, spoken
  of above, were always the same. But this is constantly altering, so
  that the time, as measured by the sun's motion, and also consequently
  as measured by a sun-dial, does not move on at a strictly uniform
  pace. This irregularity, which is slight, would be of little
  consequence in the ordinary affairs of life, but clocks and watches
  being mechanical measures of time could not, except by extreme
  complication, be made to follow this irregularity, even if desirable.

  The clock is constructed to mark uniform time in such wise that the
  length of the clock day shall be the average of all the solar days in
  the year. Four times a year the clock and the sun-dial agree exactly;
  but the sun-dial, now going a little slower, now a little faster, will
  be sometimes behind, sometimes before the clock-the greatest
  accumulated difference being about sixteen minutes for a few days in
  November, but on the average much less. The four days on which the two
  agree are April 15, June 15, September 1 and December 24.

  Clock-time is called _mean time_, that marked by the sun-dial is
  called _apparent time_, and the difference between them is the
  _equation of time_. It is given in most calendars and almanacs,
  frequently under the heading "clock slow," "clock fast." When the time
  by the sun-dial is known, the equation of time will at once enable us
  to obtain the corresponding clock-time, or vice versa.

  Atmospheric refraction introduces another error by altering the
  apparent position of the sun; but the effect is too small to need
  consideration in the construction of an instrument which, with the
  best workmanship, does not after all admit of very great accuracy.

  The general principles of dialling will now be readily understood. The
  problem before us is the following:--A rod, or _style_, as it is
  called, being firmly fixed in a direction parallel to the earth's
  axis, we have to find how and where points or lines of reference must
  be traced on some fixed surface behind the style, so that when the
  shadow of the style falls on a certain one of these lines, we may know
  that at that moment it is solar noon,--that is, that the plane through
  the style and through the sun then coincides with the meridian; again,
  that when the shadow reaches the next line of reference, it is 1
  o'clock by solar time, or, which comes to the same thing, that the
  above plane through the style and through the sun has just turned
  through the twenty-fourth part of a complete revolution; and so on for
  the subsequent hours,--the hours before noon being indicated in a
  similar manner. The style and the surface on which these lines are
  traced together constitute the dial.

  The position of an intended sun-dial having been selected--whether on
  church tower, south front of farmstead or garden wall--the surface
  must be prepared, if necessary, to receive the hour-lines.

  The chief, and in fact the only practical difficulty will be the
  accurate fixing of the style, for on its accuracy the value of the
  instrument depends. It must be in the meridian plane, and must make an
  angle with the horizon equal to the latitude of the place. The latter
  condition will offer no difficulty, but the exact determination of the
  meridian plane which passes through the point where the style is fixed
  to the surface is not so simple. At present we shall assume that the
  style has been fixed in its true position. The style itself will be
  usually a stout metal wire, and when we speak of the shadow cast by
  the style it must always be understood that the middle line of the
  thin band of shade is meant.

  The point where the style meets the dial is called the centre of the
  dial. It is the centre from which all the hour-lines radiate.

  The position of the XII o'clock line is the most important to
  determine accurately, since all the others are usually made to depend
  on this one. We cannot trace it correctly on the dial until the style
  has been itself accurately fixed in its proper place. When that is
  done the XII o'clock line will be found by the intersection of the
  dial surface with the vertical plane which contains the style; and the
  most simple way of drawing it on the dial will be by suspending a
  plummet from some point of the style whence it may hang freely, and
  waiting until the shadows of both style and plumb-line coincide on the
  dial. This single shadow will be the XII o'clock line.

  In one class of dials, namely, all the vertical ones, the XII o'clock
  line is simply the vertical line from the centre; it can, therefore,
  at once be traced on the dial face by using a fine plumb-line.

  The XII o'clock line being traced, the easiest and most accurate
  method of tracing the other hour-lines would, at the present day when
  good watches are common, be by marking where the shadow of the style
  falls when 1, 2, 3, &c., hours have elapsed since noon, and the next
  morning by the same means the forenoon hour-lines could be traced; and
  in the same manner the hours might be subdivided into halves and
  quarters, or even into minutes.

  But formerly, when watches did not exist, the tracing of the I, II,
  III, &c., o'clock lines was done by calculating the angle which each
  of these lines would make with the XII o'clock line. Now, except in
  the simple cases of a horizontal dial or of a vertical dial facing a
  cardinal point, this would require long and intricate calculations, or
  elaborate geometrical constructions, implying considerable
  mathematical knowledge, but also introducing increased chances of
  error. The chief source of error would lie in the uncertainty of the
  data; for the position of the dial-plane would have to be found before
  the calculations began,--that is, it would be necessary to know
  exactly by how many degrees it declined from the south towards the
  east or west, and by how many degrees it inclined from the vertical.
  The ancients, with the means at their disposal, could obtain these
  results only very roughly.

  Dials received different names according to their position:--

  _Horizontal dials_, when traced on a horizontal plane;

  _Vertical dials_, when on a vertical plane facing one of the cardinal
  points;

  _Vertical declining dials_, on a vertical plane not facing a cardinal
  point;

  _Inclining dials_, when traced on planes neither vertical nor
  horizontal (these were further distinguished as _reclining_ when
  leaning backwards from an observer, _proclining_ when leaning
  forwards);

  _Equinoctial dials_, when the plane is at right angles to the earth's
  axis, &c. &c.

  _Dial Construction._--A very correct view of the problem of dial
  construction may be obtained as follows:--

  [Illustration: FIG. 1.]

  Conceive a transparent cylinder (fig. 1) having an axis AB parallel to
  the axis of the earth. On the surface of the cylinder let equidistant
  generating-lines be traced 15° apart, one of them XII ... XII being in
  the meridian plane through AB, and the others I ... I, II ... II, &c.,
  following in the order of the sun's motion.

  Then the shadow of the line AB will obviously fall on the line XII ...
  XII at apparent noon, on the line I ... I at one hour after noon, on
  II ... II at two hours after noon, and so on. If now the cylinder be
  cut by any plane MN representing the plane on which the dial is to be
  traced, the shadow of AB will be intercepted by this plane and fall on
  the lines AXII AI, AII, &c.

  The construction of the dial consists in determining the angles made
  by AI, AII, &c. with AXII; the line AXII itself, being in the
  vertical plane through AB, may be supposed known.

  For the purposes of actual calculation, perhaps a transparent sphere
  will, with advantage, replace the cylinder, and we shall here apply it
  to calculate the angles made by the hour-line with the XII o'clock
  line in the two cases of a horizontal dial and of a vertical south
  dial.

  _Horizontal Dial._--Let PEp (fig. 2), the axis of the supposed
  transparent sphere, be directed towards the north and south poles of
  the heavens. Draw the two great circles, HMA, QMa, the former

  [Illustration: FIG. 2.]

  horizontal, the other perpendicular to the axis Pp, and therefore
  coinciding with the plane of the equator. Let EZ be vertical, then the
  circle QZP will be the meridian, and by its intersection A with the
  horizontal circle will determine the XII o'clock line EA. Next divide
  the equatorial circle QMa into 24 equal parts ab, bc, cd, &c. ... of
  15° each, beginning from the meridian Pa, and through the various
  points of division and the poles draw the great circles Pbp, Pcp, &c.
  ... These will exactly correspond to the equidistant generating lines
  on the cylinder in the previous construction, and the shadow of the
  style will fall on these circles after successive intervals of 1,2, 3,
  &c., hours from noon. If they meet the horizontal circle in the points
  B, C, D, &c., then EB, EC, ED, &c. ... will be the I, II, III, &c.,
  hour-lines required; and the problem of the horizontal dial consists
  in calculating the angles which these lines make with the XII o'clock
  line EA, whose position is known. The spherical triangles PAB, PAC,
  &c., enable us to do this readily. They are all right-angled at A, the
  side PA is the latitude of the place, and the angles APB, APC, &c.,
  are respectively 15°, 30°, &c., then

                  tan AB = tan 15° sin _latitude_,
                  tan AC = tan 30° sin _latitude_,
                           &c. &c.

  These determine the sides AB, AC, &c., that is, the angles AEB, AEC,
  &c., required.

  The I o'clock hour-line EB must make an angle with the meridian EA of
  11° 51' on a London dial, of 12° 31' at Edinburgh, of 11° 23' at
  Paris, 12° 0' at Berlin, 9° 55' at New York and 9° 19' at San
  Francisco. In the same way may be found the angles made by the other
  hour-lines.

  The calculations of these angles must extend throughout one quadrant
  from noon to VI o'clock, but need not be carried further, because all
  the other hour-lines can at once be deduced from these. In the first
  place the dial is symmetrically divided by the meridian, and therefore
  two times equidistant from noon will have their hour-lines equidistant
  from the meridian; thus the XI o'clock line and the I o'clock line
  must make the same angles with it, the X o'clock the same as the II
  o'clock, and so on. And next, the 24 great circles, which were drawn
  to determine these lines, are in reality only 12; for clearly the
  great circle which gives I o'clock after midnight, and that which
  gives I o'clock after noon, are one and the same, and so also for the
  other hours. Therefore the hour-lines between VI in the evening and VI
  the next morning are the prolongations of the remaining twelve.

  Let us now remove the imaginary sphere with all its circles, and
  retain only the style EP and the plane HMA with the lines traced on
  it, and we shall have the horizontal dial.

  On the longest day in London the sun rises a little before 4 o'clock,
  and sets a little after 8 o'clock; there is therefore no necessity for
  extending a London dial beyond those hours. At Edinburgh the limits
  will be a little longer, while at Hammerfest, which is within the
  Arctic circle, the whole circuit will be required.

  Instead of a wire style it is often more convenient to use a metal
  plate from one quarter to half an inch in thickness. This plate, which
  is sometimes in the form of a right-angled triangle, must have an
  acute angle equal to the latitude of the place, and, when properly
  fixed in a vertical position on the dial, its two faces must coincide
  with the meridian plane, and the sloping edges formed by the thickness
  of the plate must point to the pole and form two parallel styles.
  Since there are two styles, there must be two dials, or rather two
  half dials, because a little consideration will show that, owing to
  the thickness of the plate, these styles will only one at a time cast
  a shadow. Thus the eastern edge will give the shadow for all hours
  before 6 o'clock in the morning. From 6 o'clock until noon the western
  edge will be used. At noon it will change again to the eastern edge
  until 6 o'clock in the evening, and finally the western edge for the
  remaining hours of daylight.

  The centres of the two dials will be at the points where the styles
  meet the dial face; but, in drawing the hour-lines, we must be careful
  to draw only those lines for which the corresponding style is able to
  give a shadow as explained above. The dial will thus have the
  appearance of a single dial plate, and there will be no confusion (see
  fig. 3).

  [Illustration: FIG. 3.]

  The line of demarcation between the shadow and the light will be
  better defined than when a wire style is used; but the indications by
  this double dial will always be one minute too fast in the morning and
  one minute too slow in the afternoon. This is owing to the magnitude
  of the sun, whose angular breadth is half a degree. The well-defined
  shadows are given, not by the centre of the sun, as we should require
  them, but by the forward limb in the morning and by the backward one
  in the afternoon; and the sun takes just about a minute to advance
  through a space equal to its half-breadth.

  Dials of this description are frequently met with. The dial plate is
  of metal as well as the vertical piece upon it, and they may be
  purchased ready for placing on the pedestal,--the dial with all the
  hour-lines traced on it and the style plate firmly fastened in its
  proper position, if not even cast in the same piece with the dial
  plate.

  When placing it on the pedestal care must be taken that the dial be
  perfectly horizontal and accurately oriented. The levelling will be
  done with a spirit-level, and the orientation will be best effected
  either in the forenoon or in the afternoon, by turning the dial plate
  till the time given by the shadow (making the _one_ minute correction
  mentioned above) agrees with a good watch whose error on solar time is
  known. It is, however, important to bear in mind that a dial, so built
  up beforehand, will have the angle at the base equal to the latitude
  of some selected place, such as London, and the hour-lines will be
  drawn in directions calculated for the same latitude. Such a dial can
  therefore not be used near Edinburgh or Glasgow, although it would,
  without appreciable error, be adapted to any place whose latitude did
  not differ more than 20 or 30 m. from that of London, and it would be
  safe to employ it in Essex, Kent or Wiltshire.

  If a series of such dials were constructed, differing by 30 m. in
  latitude, then an intending purchaser could select one adapted to a
  place whose latitude was within 15 m. of his own, and the error of
  time would never exceed a small fraction of a minute. The following
  table will enable us to check the accuracy of the hour-lines and of
  the angle of the style,--all angles on the dial being readily measured
  with an ordinary protractor. It extends from 50° lat. to 59½° lat.,
  and therefore includes the whole of Great Britain and  Ireland:--

  +-------+--------+--------+---------+----------+---------+--------+
  |  LAT. |XI. A.M.| X. A.M.| IX. A.M.|VIII. A.M.|VII. A.M.|VI. A.M.|
  |       | I. P.M.|II. P.M.|III. P.M.|IIII. P.M.|  V. P.M.|VI. P.M.|
  +-------+--------+--------+---------+----------+---------+--------+
  | 50° 0'| 11° 36'| 23° 51'|  37° 27'|  53°  0' |  70° 43'| 90°  0'|
  | 50 30 | 11  41 | 24   1 |  37  39 |  53  12  |  70  51 | 90   0 |
  | 51  0 | 11  46 | 24  10 |  37  51 |  53  23  |  70  59 | 90   0 |
  | 51 30 | 11  51 | 24  19 |  38   3 |  53  35  |  71   6 | 90   0 |
  | 52  0 | 11  55 | 24  28 |  38  14 |  53  46  |  71  13 | 90   0 |
  | 52 30 | 12   0 | 24  37 |  38  25 |  53  57  |  71  20 | 90   0 |
  | 53  0 | 12   5 | 24  45 |  38  37 |  54   8  |  71  27 | 90   0 |
  | 53 30 | 12   9 | 24  54 |  38  48 |  54  19  |  71  34 | 90   0 |
  | 54  0 | 12  14 | 25   2 |  38  58 |  54  29  |  71  40 | 90   0 |
  | 54 30 | 12  18 | 25  10 |  39   9 |  54  39  |  71  47 | 90   0 |
  | 55  0 | 12  23 | 25  19 |  39  19 |  54  49  |  71  53 | 90   0 |
  | 55 30 | 12  27 | 25  27 |  39  30 |  54  59  |  71  59 | 90   0 |
  | 56  0 | 12  31 | 25  35 |  39  40 |  55   9  |  72   5 | 90   0 |
  | 56 30 | 12  36 | 25  43 |  39  50 |  55  18  |  72  11 | 90   0 |
  | 57  0 | 12  40 | 25  50 |  39  59 |  55  27  |  72  17 | 90   0 |
  | 57 30 | 12  44 | 25  58 |  40   9 |  55  36  |  72  22 | 90   0 |
  | 58  0 | 12  48 | 26   5 |  40  18 |  55  45  |  72  28 | 90   0 |
  | 58 30 | 12  52 | 26  13 |  40  27 |  55  54  |  72  33 | 90   0 |
  | 59  0 | 12  56 | 26  20 |  40  36 |  56   2  |  72  39 | 90   0 |
  | 59 30 | 13   0 | 26  27 |  40  45 |  56  11  |  72  44 | 90   0 |
  +-------+--------+--------+---------+----------+---------+--------+

  _Vertical South Dial._--Let us take again our imaginary transparent
  sphere QZPA (fig. 4), whose axis PEp is parallel to the earth's axis.
  Let Z be the zenith, and, consequently, the great circle QZP the
  meridian. Through E, the centre of the sphere, draw a vertical plane
  facing south. This will cut the sphere in the great circle ZMA, which,
  being vertical, will pass through the zenith, and, facing south, will
  be at right angles to the meridian. Let QMa be the equatorial circle,
  obtained by drawing a plane through E at right angles to the axis PEp.
  The lower portion Ep of the axis will be the style, the vertical line
  EA in the meridian plane will be the XII o'clock line, and the line
  EM, which is obviously horizontal, since M is the intersection of two
  great circles ZM, QM, each at right angles to the vertical plane QZP,
  will be the VI o'clock line. Now, as in the previous problem, divide
  the equatorial circle into 24 equal arcs of 15° each, beginning at a,
  viz. ab, bc, &c.,--each quadrant aM, MQ, &c., containing 6,--then
  through each point of division and through the axis Pp draw a plane
  cutting the sphere in 24 equidistant great circles. As the sun
  revolves round the axis the shadow of the axis will successively fall
  on these circles at intervals of one hour, and if these circles cross
  the vertical circle ZMA in the points A, B, C, &c., the shadow of the
  lower portion Ep of the axis will fall on the lines EA, EB, EC, &c.,
  which will therefore be the required hour-lines on the vertical dial,
  Ep being the style.

  [Illustration: FIG. 4.]

  There is no necessity for going beyond the VI o'clock hour-line on
  each side of noon; for, in the winter months the sun sets earlier than
  6 o'clock, and in the summer months it passes behind the plane of the
  dial before that time, and is no longer available.

  It remains to show how the angles AEB, AEC, &c., may be calculated.

  The spherical triangles pAB, pAC, &c., will give us a simple rule.
  These triangles are all right-angled at A, the side pA, equal to ZP,
  is the co-latitude of the place, that is, the difference between the
  latitude and 90°; and the successive angles ApB, ApC, &c., are 15°,
  30°, &c., respectively. Then

                  tan AB = tan 15° sin _co-latitude_;

  or more simply,

                  tan AB = tan 15° cos _latitude_,
                  tan AC = tan 30° cos _latitude_,
                           &c. &c.

  and the arcs AB, AC so found are the measure of the angles AEB, AEC,
  &c., required.

  In this ease the angles diminish as the latitudes increase, the
  opposite result to that of the horizontal dial.

  _Inclining, Reclining, &c., Dials._--We shall not enter into the
  calculation of these cases. Our imaginary sphere being, as before
  supposed, constructed with its centre at the centre of the dial, and
  all the hour-circles traced upon it, the intersection of these
  hour-circles with the plane of the dial will determine the hour-lines
  just as in the previous cases; but the triangles will no longer be
  right-angled, and the simplicity of the calculation will be lost, the
  chances of error being greatly increased by the difficulty of drawing
  the dial plane in its true position on the sphere, since that true
  position will have to be found from observations which can be only
  roughly performed.

  In all these cases, and in cases where the dial surface is not a
  plane, and the hour-lines, consequently, are not straight lines, the
  only safe practical way is to mark rapidly on the dial a few points
  (one is sufficient when the dial face is plane) of the shadow at the
  moment when a good watch shows that the hour has arrived, and
  afterwards connect these points with the centre by a continuous line.
  Of course the style must have been accurately fixed in its true
  position before we begin.

  _Equatorial Dial._--The name equatorial dial is given to one whose
  plane is at right angles to the style, and therefore parallel to the
  equator. It is the simplest of all dials. A circle (fig. 5) divided
  into 24 equal ares is placed at right angles to the style, and hour
  divisions are marked upon it. Then if care be taken that the style
  point accurately to the pole, and that the noon division coincide with
  the meridian plane, the shadow of the style will fall on the other
  divisions, each at its proper time. The divisions must be marked on
  both sides of the dial, because the sun will shine on opposite sides
  in the summer and in the winter months, changing at each equinox.

  _To find the Meridian Plane._--We have, so far, assumed the meridian
  plane to be accurately known; we shall proceed to describe some of the
  methods by which it may be found.

  [Illustration: FIG. 5.]

  The mariner's compass may be employed as a first rough approximation.
  It is well known that the needle of the compass, when free to move
  horizontally, oscillates upon its pivot and settles in a direction
  termed the magnetic meridian. This does not coincide with the true
  north and south line, but the difference between them is generally
  known with tolerable accuracy, and is called the variation of the
  compass. The variation differs widely at different parts of the
  surface of the earth, and is not stationary at any particular place,
  though the change is slow; and there is even a small daily oscillation
  which takes place about the mean position, but too small to need
  notice here (see MAGNETISM, TERRESTRIAL).

  With all these elements of uncertainty, it is obvious that the compass
  can only give a rough approximation to the position of the meridian,
  but it will serve to fix the style so that only a small further
  alteration will be necessary when a more perfect determination has
  been made.

  [Illustration: FIG. 6.]

  A very simple practical method is the following:--

  Place a table (fig. 6), or other plane surface, in such a position
  that it may receive the sun's rays both in the morning and in the
  afternoon. Then carefully level the surface by means of a
  spirit-level. This must be done very accurately, and the table in that
  position made perfectly secure, so that there be no danger of its
  shifting during the day.

  Next, suspend a plummet SH from a point S, which must be rigidly
  fixed. The extremity H, where the plummet just meets the surface,
  should be somewhere near the middle of one end of the table. With H
  for centre, describe any number of concentric arcs of circles, AB, CD,
  EF, &c.

  A bead P, kept in its place by friction, is threaded on the plummet
  line at some convenient height above H.

  Everything being thus prepared, let us follow the shadow of the bead P
  as it moves along the surface of the table during the day. It will be
  found to describe a curve ACE ... FDB, approaching the point H as the
  sun advances towards noon, and receding from it afterwards. (The curve
  is a conic section--an hyperbola in these regions.) At the moment when
  it crosses the arc AB, mark the point A; AP is then the direction of
  the sun, and, as AH is horizontal, the angle PAH is the altitude of
  the sun. In the afternoon mark the point B where it crosses the same
  arc; then the angle PBH is the altitude. But the right-angled
  triangles PHA, PHB are obviously equal; and the sun has therefore the
  same altitudes at those two instants, the one before, the other after
  noon. It follows that, _if the sun has not changed its declination_
  during the interval, the two positions will be symmetrically placed
  one on each side of the meridian. Therefore, drawing the chord AB, and
  bisecting it in M, HM will be the meridian line.

  Each of the other concentric arcs, CD, EF, &c., will furnish its
  meridian line. Of course these should all coincide, but if not, the
  mean of the positions thus found must be taken.

  The proviso mentioned above, that the sun has not changed its
  declination, is scarcely ever realized; but the change is slight, and
  may be neglected, except perhaps about the time of the equinoxes, at
  the end of March and at the end of September. Throughout the remainder
  of the year the change of declination is so slow that we may safely
  neglect it. The most favourable times are at the end of June and at
  the end of December, when the sun's declination is almost stationary.
  If the line HM be produced both ways to the edges of the table, then
  the two points on the ground vertically below those on the edges may
  be found by a plummet, and, if permanent marks be made there, the
  meridian plane, which is the vertical plane passing through these two
  points, will have its position perfectly secured.

  _To place the Style of a Dial in its True Position._--Before giving
  any other method of finding the meridian plane, we shall complete the
  construction of the dial, by showing how the style may now be
  accurately placed in its true position. The angle which the style
  makes with a hanging plumb-line, being the co-latitude of the place,
  is known, and the north and south direction is also roughly given by
  the mariner's compass. The style may therefore be already adjusted
  approximately--correctly, indeed, as to its inclination--but probably
  requiring a little horizontal motion east or west. Suspend a fine
  plumb-line from some point of the style, then the style will be
  properly adjusted if, at the very instant of noon, its shadow falls
  exactly on the plumb-line,--or, which is the same thing, if both
  shadows coincide on the dial.

  This instant of noon will be given very simply, by the meridian plane,
  whose position we have secured by the two permanent marks on the
  ground. Stretch a cord from the one mark to the other. This will not
  generally be horizontal, but the cord will be wholly in the meridian
  plane, and that is the only necessary condition. Next, suspend a
  plummet over the mark which is nearer to the sun, and, when the shadow
  of the plumb-line falls on the stretched cord, it is noon. A signal
  from the observer there to the observer at the dial enables the latter
  to adjust the style as directed above.

  _Other Methods of finding the Meridian Plane._--We have dwelt at some
  length on these practical operations because they are simple and
  tolerably accurate, and because they want neither watch, nor sextant,
  nor telescope--nothing more, in fact, than the careful observation of
  shadow lines.

  The Pole star, or _Ursae Minoris_, may also be employed for finding
  the meridian plane without other apparatus than plumb-lines. This star
  is now only about 1° 14' from the pole; if therefore a plumb-line be
  suspended at a few feet from the observer, and if he shift his
  position till the star is exactly hidden by the line, then the plane
  through his eye and the plumb-line will never be far from the meridian
  plane. Twice in the course of the twenty-four hours the planes would
  be strictly coincident. This would be when the star crosses the
  meridian above the pole, and again when it crosses it below. If we
  wished to employ the method of determining the meridian, the times of
  the stars crossing would have to be calculated from the data in the
  _Nautical Almanac_, and a watch would be necessary to know when the
  instant arrived. The watch need not, however, be very accurate,
  because the motion of the star is so slow that an error of ten minutes
  in the time would not give an error of one-eighth of a degree in the
  azimuth.

  The following accidental circumstance enables us to dispense with both
  calculation and watch. The right ascension of the star [eta] _Ursae
  Majoris_, that star in the tail of the Great Bear which is farthest
  from the "pointers," happens to differ by a little more than 12 hours
  from the right ascension of the Pole star. The great circle which
  joins the two stars passes therefore close to the pole. When the Pole
  star, at a distance of about 1° 14' from the pole, is crossing the
  meridian above the pole, the star [eta] _Ursae Majoris_, whose polar
  distance is about 40°, has not yet reached the meridian below the
  pole.

  When [eta] _Ursae Majoris_ reaches the meridian, which will be within
  half an hour later, the Pole star will have left the meridian; but its
  slow motion will have carried it only a very little distance away. Now
  at some instant between these two times--much nearer the latter than
  the former--the great circle joining the two stars will be exactly
  vertical; and at this instant, which the observer determines by seeing
  that the plumb-line hides the two stars simultaneously, neither of the
  stars is strictly in the meridian; but the deviation from it is so
  small that it may be neglected, and the plane through the eye and the
  plumb-line taken for meridian plane.

  In all these cases it will be convenient, instead of fixing the plane
  by means of the eye and one fixed plummet, to have a second plummet at
  a short distance in front of the eye; this second plummet, being
  suspended so as to allow of lateral shifting, must be moved so as
  always to be between the eye and the fixed plummet. The meridian plane
  will be secured by placing two permanent marks on the ground, one
  under each plummet.

  This method, by means of the two stars, is only available for the
  upper transit of _Polaris_; for, at the lower transit, the other star
  [eta] _Ursae Majoris_ would pass close to or beyond the zenith, and
  the observation could not be made. Also the stars will not be visible
  when the upper transit takes place in the daytime, so that one-half of
  the year is lost to this method.

  Neither could it be employed in lower latitudes than 40° N., for there
  the star would be below the horizon at its lower transit;--we may even
  say not lower than 45° N., for the star must be at least 5° above the
  horizon before it becomes distinctly visible.

  There are other pairs of stars which could be similarly employed, but
  none so convenient as these two, on account of _Polaris_ with its very
  slow motion being one of the pair.

  _To place the Style in its True Position without previous
  Determination of the Meridian Plane._--The various methods given above
  for finding the meridian plane have for ultimate object the
  determination of the plane, not on its own account, but as an element
  for fixing the instant of noon, whereby the style may be properly
  placed.

  We shall dispense, therefore, with all this preliminary work if we
  determine noon by astronomical observation. For this we shall want a
  good watch, or pocket chronometer, and a sextant or other instrument
  for taking altitudes. The local time at any moment may be determined
  in a variety of ways by observation of the celestial bodies. The
  simplest and most practically useful methods will be found described
  and investigated in any work on astronomy.

  For our present purpose a single altitude of the sun taken in the
  forenoon will be most suitable. At some time in the morning, when the
  sun is high enough to be free from the mists and uncertain refractions
  of the horizon--but to ensure accuracy, while the rate of increase of
  the altitude is still tolerably rapid, and, therefore, not later than
  10 o'clock--take an altitude of the sun, an assistant, at the same
  moment, marking the time shown by the watch. The altitude so observed
  being properly corrected for refraction, parallax, &c., will, together
  with the latitude of the place, and the sun's declination, taken from
  the _Nautical Almanac_, enable us to calculate the time. This will be
  the solar or apparent time, that is, the very time we require.
  Comparing the time so found with the time shown by the watch, we see
  at once by how much the watch is fast or slow of solar time; we know,
  therefore, exactly what time the watch must mark when solar noon
  arrives, and waiting for that instant we can fix the style in its
  proper position as explained before.

  We can dispense with the sextant and with all calculation and
  observation if, by means of the pocket chronometer, we bring the time
  from some observatory where the work is done; and, allowing for the
  change of longitude, and also for the equation of time, if the time we
  have brought is clock time, we shall have the exact instant of solar
  noon as in the previous case.

  In former times the fancy of dialists seems to have run riot in
  devising elaborate surfaces on which the dial was to be traced.
  Sometimes the shadow was received on a cone, sometimes on a cylinder,
  or on a sphere, or on a combination of these. A universal dial was
  constructed of a figure in the shape of a cross; another universal
  dial showed the hours by a globe and by several gnomons. These
  universal dials required adjusting before use, and for this a
  mariner's compass and a spirit-level were necessary. But it would be
  tedious and useless to enumerate the various forms designed, and, as a
  rule, the more complex the less accurate.

  Another class of useless dials consisted of those with variable
  centres. They were drawn on fixed horizontal planes, and each day the
  style had to be shifted to a new position. Instead of hour-_lines_
  they had hour-_points_; and the style, instead of being parallel to
  the axis of the earth, might make any chosen angle with the horizon.
  There was no practical advantage in their use, but rather the reverse;
  and they can only be considered as furnishing material for new
  mathematical problems.

  _Portable Dials._--The dials so far described have been fixed dials,
  for even the fanciful ones to which reference was just now made were
  to be fixed before using. There were, however, other dials, made
  generally of a small size, so as to be carried in the pocket; and
  these, so long as the sun shone, roughly answered the purpose of a
  watch.

  The description of the portable dial has generally been mixed up with
  that of the fixed dial, as if it had been merely a special case, and
  the same principle had been the basis of both; whereas there are
  essential points of difference between them, besides those which are
  at once apparent.

  In the fixed dial the result depends on the _uniform_ angular motion
  of the sun round the fixed style; and a small error in the assumed
  position of the sun, whether due to the imperfection of the
  instrument, or to some small neglected correction, has only a trifling
  effect on the time. This is owing to the angular displacement of the
  sun being so rapid--a quarter of a degree every minute--that for the
  ordinary affairs of life greater accuracy is not required, as a
  displacement of a quarter of a degree, or at any rate of one degree,
  can be readily seen by nearly every person. But with a portable dial
  this is no longer the case. The uniform angular motion is not now
  available, because we have no determined fixed plane to which we may
  refer it. In the new position, to which the observer has gone, the
  zenith is the only point of the heavens he can at once practically
  find; and the basis for the determination of the time is the
  constantly but _very irregularly_ varying zenith distance of the sun.

  At sea the observation of the altitude of a celestial body is the only
  method available for finding local time; but the perfection which has
  been attained in the construction of the sextant enables the sailor to
  reckon on an accuracy of seconds. Certain precautions have, however,
  to be taken. The observations must not be made within a couple of
  hours of noon, on account of the slow rate of change at that time, nor
  too near the horizon, on account of the uncertain refractions there;
  and the same restrictions must be observed in using a portable dial.

  To compare roughly the accuracy of the fixed and the portable dials,
  let us take a mean position in Great Britain, say 54° lat., and a mean
  declination when the sun is in the equator. It will rise at 6 o'clock,
  and at noon have an altitude of 36°,--that is, the portable dial will
  indicate an average change of one-tenth of a degree in each minute, or
  two and a half times slower than the fixed dial. The vertical motion
  of the sun increases, however, nearer the horizon, but even there it
  will be only one-eighth of a degree each minute, or half the rate of
  the fixed dial, which goes on at nearly the same speed throughout the
  day.

  Portable dials are also much more restricted in the range of latitude
  for which they are available, and they should not be used more than 4
  or 5 m. north or south of the place for which they were constructed.

  We shall briefly describe two portable dials which were in actual use.

  _Dial on a Cylinder._--A hollow cylinder of metal (fig. 7), 4 or 5 in.
  high, and about an inch in diameter, has a lid which admits of
  tolerably easy rotation. A hole in the lid receives the style shaped
  somewhat like a bayonet; and the straight part of the style, which, on
  account of the two bends, is lower than the lid, projects horizontally
  out from the cylinder to a distance of 1 or 1½ in. When not in use the
  style would be taken out and placed inside the cylinder.

  A horizontal circle is traced on the cylinder opposite the projecting
  style, and this circle is divided into 36 approximately equidistant
  intervals.[2] These intervals represent spaces of time, and to each
  division is assigned a date, so that each month has three dates marked
  as follows:-January 10, 20, 31; February 10, 20, 28; March 10, 20, 31;
  April 10, 20, 30, and so on,--always the 10th, the 20th, and the last
  day of each month.

  [Illustration: FIG. 7.]

  Through each point of division a vertical line parallel to the axis of
  the cylinder is drawn from top to bottom. Now it will be readily
  understood that if, upon one of these days, the lid be turned, so as
  to bring the style exactly opposite the date, and if the dial be then
  placed on a horizontal table so as to receive sunlight, and turned
  round bodily until the shadow of the style falls exactly on the
  vertical line below it, the shadow will terminate at some definite
  point of this line, the position of which point will depend on the
  length of the style--that is, the distance of its end from the surface
  of the cylinder--and on the altitude of the sun at that instant.
  Suppose that the observations are continued all day, the cylinder
  being very gradually turned so that the style may always face the sun,
  and suppose that marks are made on the vertical line to show the
  extremity of the shadow at each exact hour from sun-rise to
  sun-set-these times being taken from a good fixed sun-dial,--then it is
  obvious that the next year, on the _same date_, the sun's declination
  being about the same, and the observer in about the same latitude, the
  marks made the previous year will serve to tell the time all that day.

  What we have said above was merely to make the principle of the
  instrument clear, for it is evident that this mode of marking, which
  would require a whole year's sunshine and hourly observation, cannot
  be the method employed.

  The positions of the marks are, in fact, obtained by calculation.
  Corresponding to a given date, the declination of the sun is taken
  from the almanac, and this, together with the latitude of the place
  and the length of the style, will constitute the necessary data for
  computing the length of the shadow, that is, the distance of the mark
  below the style for each successive hour.

  We have assumed above that the declination of the sun is the same at
  the same date in different years. This is not quite correct, but, if
  the dates be taken for the second year after leap year, the results
  will be sufficiently approximate.

  When all the hour-marks have been placed opposite to their respective
  dates, then a continuous curve, joining the corresponding hour-points,
  will serve to find the time for a day intermediate to those set down,
  the lid being turned till the style occupy a proper position between
  the two divisions. The horizontality of the surface on which the
  instrument rests is a very necessary condition, especially in summer,
  when, the shadow of the style being long, the extreme end will shift
  rapidly for a small deviation from the vertical, and render the
  reading uncertain. The dial can also be used by holding it up by a
  small ring in the top of the lid, and probably the vertically is
  better ensured in that way.

  _Portable Dial on a Card._--This neat and very ingenious dial is
  attributed by Ozanam to a Jesuit Father, De Saint Rigaud, and probably
  dates from the early part of the 17th century. Ozanam says that it was
  sometimes called the _capuchin_, from some fancied resemblance to a
  cowl thrown back.

  _Construction._--Draw a straight line ACB parallel to the top of the
  card (fig. 8) and another DCE at right angles to it; with C as
  centre, and any convenient radius CA, describe the semicircle AEB
  below the horizontal. Divide the whole arc AEB into 12 equal parts at
  the points r, s, t, &c., and through these points draw perpendiculars
  to the diameter ACB; these lines will be the hour-lines, viz. the line
  through r will be the XI ... I line, the line through s the X ... II
  line, and so on; the hour-line of noon will be the point A itself; by
  subdivision of the small arcs Ar, rs, st, &c., we may draw the
  hour-lines corresponding to halves and quarters, but this only where
  it can be done without confusion.

  Draw ASD making with AC an angle equal to the latitude of the place,
  and let it meet EC in D, through which point draw FDG at right angles
  to AD.

  With centre A, and any convenient radius AS, describe an arc of circle
  RST, and graduate this arc by marking degree divisions on it,
  extending from 0° at S to 23½° on each side at R and T. Next determine
  the points on the straight line FDG where radii drawn from A to the
  degree divisions on the arc would cross it, and carefully mark these
  crossings.

  [Illustration: FIG. 8.]

  The divisions of RST are to correspond to the sun's declination, south
  declinations on RS and north declinations on ST. In the other
  hemisphere of the earth this would be reversed; the north declinations
  would be on the upper half.

  Now, taking a second year after leap year (because the declinations of
  that year are about the mean of each set of four years), find the days
  of the month when the sun has these different declinations, and place
  these dates, or so many of them as can be shown without confusion,
  opposite the corresponding marks on FDG. Draw the _sun-line_ at the
  top of the card parallel to the line ACB; and, near the extremity, to
  the right, draw any small figure intended to form, as it were, a door
  of which a b shall be the hinge. Care must be taken that this hinge is
  exactly at right angles to the _sun-line_. Make a fine open slit c d
  right through the card and extending from the hinge to a short
  distance on the door,--the centre line of this slit coinciding
  accurately with the _sun-line_. Now, cut the door completely through
  the card; except, of course, along the hinge, which, when the card is
  thick, should be partly cut through at the back, to facilitate the
  opening. Cut the card right through along the line FDG, and pass a
  thread carrying a little plummet W and a _very_ small bead P; the bead
  having sufficient friction with the thread to retain any position when
  acted on only by its own weight, but sliding easily along the thread
  when moved by the hand. At the back of the card the thread terminates
  in a knot to hinder it from being drawn through; or better, because
  giving more friction and a better hold, it passes through the centre
  of a small disk of card--a fraction of an inch in diameter--and, by a
  knot, is made fast at the back of the disk.

  To complete the construction,--with the centres F and G, and radii FA
  and GA, draw the two arcs AY and AZ which will limit the hour-lines;
  for in an observation the bead will always be found between them. The
  forenoon and afternoon hours may then be marked as indicated in the
  figure. The dial does not of itself discriminate between forenoon and
  afternoon; but extraneous circumstances, as, for instance, whether the
  sun is rising or falling, will settle that point, except when close to
  noon, where it will always be uncertain.

  To _rectify_ the dial (using the old expression, which means to
  prepare the dial for an observation),--open the small door, by turning
  it about its hinge, till it stands well out in front. Next, set the
  thread in the line FG opposite the day of the month, and stretching it
  over the point A, slide the bead P along till it exactly coincide
  with A.

  To find the hour of the day,--hold the dial in a vertical position in
  such a way that its plane may pass through the sun. The verticality is
  ensured by seeing that the bead rests against the card without
  pressing. Now gradually tilt the dial (without altering its vertical
  plane), until the central line of sunshine, passing through the open
  slit of the door, just falls along the sun-line. The hour-line against
  which the bead P then rests indicates the time.

  [Illustration: FIG. 9.]

  The _sun-line_ drawn above has always, so far as we know, been used as
  a _shadow-line_. The upper edge of the rectangular door was the
  prolongation of the line, and, the door being opened, the dial was
  gradually tilted until the shadow cast by the upper edge exactly
  coincided with it. But this shadow tilts the card one-quarter of a
  degree more than the sun-line, because it is given by that portion of
  the sun which just appears above the edge, that is, by the upper limb
  of the sun, which is one-quarter of a degree higher than the centre.
  Now, even at some distance from noon, the sun will sometimes take a
  considerable time to rise one-quarter of a degree, and by so much time
  will the indication of the dial be in error.

  The central line of light which comes through the open slit will be
  free from this error, because it is given by light from the centre of
  the sun.

  The card-dial deserves to be looked upon as something more than a mere
  toy. Its ingenuity and scientific accuracy give it an educational
  value which is not to be measured by the roughness of the results
  obtained.

  The theory of this instrument is as follows:--Let H (fig. 9) be the
  point of suspension of the plummet at the time of observation, so that
  the angle DAH is the north declination of the sun,--P, the bead,
  resting against the hour-line VX. Join CX, then the angle ACX is the
  hour-angle from noon given by the bead, and we have to prove that this
  hour-angle is the correct one corresponding to a north latitude DAC, a
  north declination DAH and an altitude equal to the angle which the
  _sun-line_, or its parallel AC, makes with the horizontal. The angle
  PHQ will be equal to the altitude, if HQ be drawn parallel to DC, for
  the pair of lines HQ, HP will be respectively at right angles to the
  sun-line and the horizontal.

  Draw PQ and HM parallel to AC, and let them meet DCE in M and N
  respectively.

  Let HP and its equal HA be represented by a. Then the following values
  will be readily deduced from the figure:--

  AD = a cos _decl._ DH = a sin _decl._ PQ = a sin _alt._

     CX = AC = AD cos _lat._ = a cos _decl._ cos _lat._
     PN = CV = CX cos ACX = a cos _decl._ cos _lat._ cos ACX.
     NQ = MH = DH sin MDH = sin _decl._ sin _lat._
       (:. the angle MDH = DAC = latitude.)

  And since           PQ = NQ + PN,
  we have, by simple substitution,
  a sin _alt._ = a sin _decl._ sin _lat._ + a cos _del._ cos _lat._
  cos ACX; or, dividing by a throughout,

  sin _alt._ = sin _decl._ sin _lat._ + cos _decl._ cos _lat._
                                                        cos ACX ... (1)
  which equation determines the hour-angle ACX shown by the bead.

  To determine the hour-angle of the sun at the same moment, let fig. 10
  represent the celestial sphere, HR the horizon, P the pole, Z the
  zenith and S the sun.

  From the spherical triangle PZS, we have
      cos ZS = cos PS cos ZP + sin PS sin ZP cos ZPS
          but ZS = zenith distance = 90° - altitude
              ZP = 90° - PR        = 90°- latitude
              PS = polar distance  = 90° - declination,
  therefore, by substitution

  sin _alt._ = sin _decl._ sin _lat._ + cos _decl._ cos _lat._
                                                       cos ZPS ... (2)
  and ZPS is the hour-angle of the sun.

  A comparison of the two formulae (1) and (2) shows that the hour-angle
  given by the bead will be the same as that given by the sun, and
  proves the theoretical accuracy of the card-dial. Just at sun-rise or
  at sun-set the amount of refraction slightly exceeds half a degree.
  If, then, a little cross m (see fig. 8) be made just below the
  sun-line, at a distance from it which would subtend half a degree at
  c, the time of sun-set would be found corrected for refraction, if the
  central line of light were made to fall on cm.

  [Illustration: FIG. 10.]

  LITERATURE.--The following list includes the principal writers on
  dialling whose works have come down, to us, and to these we must refer
  for descriptions of the various constructions, some simple and direct,
  others fanciful and intricate, which have been at different times
  employed: Ptolemy, _Analemma_, restored by Commandine; Vitruvius,
  _Architecture_; Sebastian Münster, _Horologiographia_; Orontius
  Fineus, _De horologiis solaribus_; Mutio Oddi da Urbino, _Horologi
  solari_; Dryander, _De horologiorum compositione_; Conrad Gesner,
  _Pandectae_; Andreas Schöner, _Gnomonicae_; F. Commandine,
  _Horologiorum descriptio_; Joan. Bapt. Benedictus, _De gnomonum usu_;
  Georgius Schomberg, _Exegesis fundamentorum gnomonicorum_; Joan.
  Solomon de Caus, _Horologes solaires_; Joan. Bapt. Trolta, _Praxis
  horologiorum_; Desargues, _Manière universelle pour poser l'essieu_,
  &c.; Ath. Kircher, _Ars magna lucis et Umbrae_; Hallum, _Explicatio
  horologii in horto regio Londini_; Joan. Mark, _Tractatus
  horologiorum_; Clavius, _Gnomonices de horologiis_. Also among more
  modern writers, Deschales, Ozanam, Schottus, Wolfius, Picard, Lahire,
  Walper; in German, Paterson, Michael, Müller; in English, Foster,
  Wells, Collins, Leadbetter, Jones, Leybourn, Emerson and Ferguson. See
  also Hans Löschner, _Über Sonnenuhren_ (2nd ed., Graz, 1906).  (H. G.)

[1] In one of the courts of Queens' College, Cambridge, there is an
elaborate sun-dial dating from the end of the 17th or beginning of the
18th century, and around it a series of numbers which make it available
as a moon-dial when the moon's age is known.

[2] Strict equality is not necessary, as the observations made are on
the vertical line through each division-point, without reference to the
others. It is not even requisite that the divisions should go completely
and exactly round the cylinder, although they were always so drawn, and
both these conditions were insisted upon in the directions for the
construction.


DIALECT (from Gr. [Greek: dialektos], conversation, manner of speaking,
[Greek: dialegesthai], to converse), a particular or characteristic
manner of speech, and hence any variety of a language. In its widest
sense languages which are branches of a common or parent language may be
said to be "dialects" of that language; thus Attic, Ionic, Aeolic and
Doric are dialects of Greek, though there may never have at any time
been a separate language of which they were variations; so the various
Romance languages, Italian, French, Spanish, &c., were dialects of
Latin. Again, where there have existed side by side, as in England,
various branches of a language, such as the languages of the Angles, the
Jutes or the Saxons, and the descendant of one particular language, from
many causes, has obtained the predominance, the traces of the other
languages remain in the "dialects" of the districts where once the
original language prevailed. Thus it may be incorrect, from the
historical point of view, to say that "dialect" varieties of a language
represent degradations of the standard language. A "literary" accepted
language, such as modern English, represents the original language
spoken in the Midlands, with accretions of Norman, French, and later
literary and scientific additions from classical and other sources,
while the present-day "dialects" preserve, in inflections, pronunciation
and particular words, traces of the original variety of the language not
incorporated in the standard language of the country. See the various
articles on languages (English, French, &c).


DIALECTIC, or DIALECTICS (from Gr. [Greek: dialektos], discourse,
debate; [Greek: ê dialektikê], sc. [Greek: technê], the art of debate),
a logical term, generally used in common parlance in a contemptuous
sense for verbal or purely abstract disputation devoid of practical
value. According to Aristotle, Zeno of Elea "invented" dialectic, the
art of disputation by question and answer, while Plato developed it
metaphysically in connexion with his doctrine of "Ideas" as the art of
analysing ideas in themselves and in relation to the ultimate idea of
the Good (_Repub._ vii.). The special function of the so-called
"Socratic dialectic" was to show the inadequacy of popular beliefs.
Aristotle himself used "dialectic," as opposed to "science," for that
department of mental activity which examines the presuppositions lying
at the back of all the particular sciences. Each particular science has
its own subject matter and special principles ([Greek: idiai archai]) on
which the superstructure of its special discoveries is based. The
Aristotelian dialectic, however, deals with the universal laws ([Greek:
koinai archai]) of reasoning, which can be applied to the particular
arguments of all the sciences. The sciences, for example, all seek to
define their own species; dialectic, on the other hand, sets forth the
conditions which all definitions must satisfy whatever their subject
matter. Again, the sciences all seek to educe general laws; dialectic
investigates the nature of such laws, and the kind and degree of
necessity to which they can attain. To this general subject matter
Aristotle gives the name "Topics" ([Greek: topoi], loci, communes loci).
"Dialectic" in this sense is the equivalent of "logic." Aristotle also
uses the term for the science of probable reasoning as opposed to
demonstrative reasoning ([Greek: apodeiktikê]). The Stoics divided
[Greek: logikê] (logic) into rhetoric and dialectic, and from their time
till the end of the middle ages dialectic was either synonymous with, or
a part of, logic.

In modern philosophy the word has received certain special meanings. In
Kantian terminology _Dialektik_ is the name of that portion of the
_Kritik d. reinen Vernunft_ in which Kant discusses the impossibility of
applying to "things-in-themselves" the principles which are found to
govern phenomena. In the system of Hegel the word resumes its original
Socratic sense, as the name of that intellectual process whereby the
inadequacy of popular conceptions is exposed. Throughout its history,
therefore, "dialectic" has been connected with that which is remote
from, or alien to, unsystematic thought, with the a priori, or
transcendental, rather than with the facts of common experience and
material things.


DIALLAGE, an important mineral of the pyroxene group, distinguished by
its thin foliated structure and bronzy lustre. The chemical composition
is the same as diopside, Ca Mg (SiO_{3})_{2}, but it sometimes contains
the molecules (Mg, Fe") (Al, Fe"')_{2} SiO_{6} and Na Fe"'
(SiO_{3})_{2}, in addition, when it approaches to augite in composition.
Diallage is in fact an altered form of these varieties of pyroxene; the
particular kind of alteration which they have undergone being known as
"schillerization." This, as described by Prof. J. W. Judd, consists in
the development of a fine lamellar structure or parting due to secondary
twinning and the separation of secondary products along these and other
planes of chemical weakness ("solution planes") in the crystal. The
secondary products consist of mixtures of various hydrated oxides--opal,
göthite, limonite, &c--and appear as microscopic inclusions filling or
partly filling cavities, which have definite outlines with respect to
the enclosing crystal and are known as negative crystals. It is to the
reflection and interference of light from these minute inclusions that
the peculiar bronzy sheen or "schiller" of the mineral is due. The most
pronounced lamination is that parallel to the orthopinacoid; another,
less distinct, is parallel to the basal plane, and a third parallel to
the plane of symmetry; these planes of secondary parting are in addition
to the ordinary prismatic cleavage of all pyroxenes. Frequently the
material is interlaminated with a rhombic pyroxene (bronzite) or with an
amphibole (smaragdite or uralite), the latter being an alteration
product of the diallage.

Diallage is usually greyish-green or dark green, sometimes brown, in
colour, and has a pearly to metallic lustre or schiller on the laminated
surfaces. The hardness is 4, and the specific gravity 3.2 to 3.35. It
does not occur in distinct crystals with definite outlines, but only as
lamellar masses in deep-seated igneous rocks, principally gabbro, of
which it is an essential constituent. It occurs also in some peridotites
and serpentines, and rarely in volcanic rocks (basalt) and crystalline
schists. Masses of considerable size are found in the coarse-grained
gabbros of the Island of Skye, Le Prese near Bornio in Valtellina,
Lombardy, Prato near Florence, and many other localities.

The name diallage, from diallage, "difference," in allusion to the
dissimilar cleavages and planes of fracture, as originally applied by R.
J. Haüy in 1801, included other minerals (the orthorhombic pyroxenes
hypersthene, bronzite and bastite, and the smaragdite variety of
hornblende) which exhibit the same peculiarities of schiller structure;
it is now limited to the monoclinic pyroxenes with this structure. Like
the minerals of similar appearance just mentioned, it is sometimes cut
and polished for ornamental purposes.                        (L. J. S.)


DIALOGUE, properly the conversation between two or more persons,
reported in writing, a form of literature invented by the Greeks for
purposes of rhetorical entertainment and instruction, and scarcely
modified since the days of its invention. A dialogue is in reality a
little drama without a theatre, and with scarcely any change of scene.
It should be illuminated with those qualities which La Fontaine
applauded in the dialogue of Plato, namely vivacity, fidelity of tone,
and accuracy in the opposition of opinions. It has always been a
favourite with those writers who have something to censure or to impart,
but who love to stand outside the pulpit, and to encourage others to
pursue a train of thought which the author does not seem to do more than
indicate. The dialogue is so spontaneous a mode of expressing and noting
down the undulations of human thought that it almost escapes analysis.
All that is recorded, in any literature, of what pretend to be the
actual words spoken by living or imaginary people is of the nature of
dialogue. One branch of letters, the drama, is entirely founded upon it.
But in its technical sense the word is used to describe what the Greek
philosophers invented, and what the noblest of them lifted to the
extreme refinement of an art.

The systematic use of dialogue as an independent literary form is
commonly supposed to have been introduced by Plato, whose earliest
experiment in it is believed to survive in the _Laches_. The Platonic
dialogue, however, was founded on the mime, which had been cultivated
half a century earlier by the Sicilian poets, Sophron and Epicharmus.
The works of these writers, which Plato admired and imitated, are lost,
but it is believed that they were little plays, usually with only two
performers. The recently discovered mimes of Herodas (Herondas) give us
some idea of their scope. Plato further simplified the form, and reduced
it to pure argumentative conversation, while leaving intact the amusing
element of character-drawing. He must have begun this about the year
405, and by 399 he had brought the dialogue to its highest perfection,
especially in the cycle directly inspired by the death of Socrates. All
his philosophical writings, except the _Apology_, are cast in this form.
As the greatest of all masters of Greek prose style, Plato lifted his
favourite instrument, the dialogue, to its highest splendour, and to
this day he remains by far its most distinguished proficient. In the 2nd
century a.d. Lucian of Samosata achieved a brilliant success with his
ironic dialogues "Of the Gods," "Of the Dead," "Of Love" and "Of the
Courtesans." In some of them he attacks superstition and philosophical
error with the sharpness of his wit; in others he merely paints scenes
of modern life. The title of Lucian's most famous collection was
borrowed in the 17th century by two French writers of eminence, each of
whom prepared _Dialogues des morts_. These were Fontenelle (1683) and
Fénelon (1712). In English non-dramatic literature the dialogue had not
been extensively employed until Berkeley used it, in 1713, for his
Platonic treatise, _Hylas and Philonous_. Landor's _Imaginary
Conversations_ (1821-1828) is the most famous example of it in the 19th
century, although the dialogues of Sir Arthur Helps claim attention. In
Germany, Wieland adopted this form for several important satirical works
published between 1780 and 1799. In Spanish literature, the Dialogues of
Valdés (1528) and those on Painting (1633) by Vincenzo Carducci, are
celebrated. In Italian, collections of dialogues, on the model of Plato,
have been composed by Torquato Tasso (1586), by Galileo (1632), by
Galiani (1770), by Leopardi (1825), and by a host of lesser writers. In
our own day, the French have returned to the original application of
dialogue, and the inventions of "Gyp," of Henri Lavedan and of others,
in which a mundane anecdote is wittily and maliciously told in
conversation, would probably present a close analogy to the lost mimes
of the early Sicilian poets, if we could meet with them. This kind of
dialogue has been employed in English, and with conspicuous cleverness
by Mr Anstey Guthrie, but it does not seem so easily appreciated by
English as by French readers. (E.G.)


DIALYSIS (from the Gr. [Greek: dia], through, [Greek: luein], to
loosen), in chemistry, a process invented by Thomas Graham for
separating colloidal and crystalline substances. He found that solutions
could be divided into two classes according to their action upon a
porous diaphragm such as parchment. If a solution, say of salt, be
placed in a drum provided with a parchment bottom, termed a "dialyser,"
and the drum and its contents placed in a larger vessel of water, the
salt will pass through the membrane. If the salt solution be replaced by
one of glue, gelatin or gum, it will be found that the membrane is
impermeable to these solutes. To the first class Graham gave the name
"crystalloids," and to the second "colloids." This method is
particularly effective in the preparation of silicic acid. By adding
hydrochloric acid to a dilute solution of an alkaline silicate, no
precipitate will fall and the solution will contain hydrochloric acid,
an alkaline chloride, and silicic acid. If the solution be transferred
to a dialyser, the hydrochloric acid and alkaline chloride will pass
through the parchment, while the silicic acid will be retained.


DIAMAGNETISM. Substances which, like iron, are attracted by the pole of
an ordinary magnet are commonly spoken of as magnetic, all others being
regarded as non-magnetic. It was noticed by A. C. Becquerel in 1827 that
a number of so-called non-magnetic bodies, such as wood and gum lac,
were influenced by a very powerful magnet, and he appears to have formed
the opinion that the influence was of the same nature as that exerted
upon iron, though much feebler, and that all matter was more or less
magnetic. Faraday showed in 1845 (_Experimental Researches_, vol. iii.)
that while practically all natural substances are indeed acted upon by a
sufficiently strong magnetic pole, it is only a comparatively small
number that are attracted like iron, the great majority being repelled.
Bodies of the latter class were termed by Faraday _diamagnetics_. The
strongest diamagnetic substance known is bismuth, its susceptibility
being--0.000014, and its permeability 0.9998. The diamagnetic quality of
this metal can be detected by means of a good permanent magnet, and its
repulsion by a magnetic pole had been more than once recognized before
the date of Faraday's experiments. The metals gold, silver, copper,
lead, zinc, antimony and mercury are all diamagnetic; tin, aluminium and
platinum are attracted by a very strong pole. (See MAGNETISM.)


DIAMANTE, FRA, Italian fresco painter, was born at Prato about 1400. He
was a Carmelite friar, a member of the Florentine community of that
order, and was the friend and assistant of Filippo Lippi. The Carmelite
convent of Prato which he adorned with many works in fresco has been
suppressed, and the buildings have been altered to a degree involving
the destruction of the paintings. He was the principal assistant of Fra
Filippo in the grand frescoes which may still be seen at the east end of
the cathedral of Prato. In the midst of the work he was recalled to
Florence by his conventual superior, and a minute of proceedings of the
commune of Prato is still extant, in which it is determined to petition
the metropolitan of Florence to obtain his return to Prato,--a proof
that his share in the work was so important that his recall involved the
suspension of it. Subsequently he assisted Fra Filippo in the execution
of the frescoes still to be seen in the cathedral of Spoleto, which Fra
Diamante completed in 1470 after his master's death in 1469. Fra Filippo
left a son ten years old to the care of Diamante, who, having received
200 ducats from the commune of Spoleto, as the balance due for the work
done in the cathedral, returned with the child to Florence, and, as
Vasari says, bought land for himself with the money, giving but a small
portion to the child. The accusation of wrong-doing, however, would
depend upon the share of the work executed by Fra Diamante, and the
terms of his agreement with Fra Filippo. Fra Diamante must have been
nearly seventy when he completed the frescoes at Spoleto, but the exact
year of his death is not known.


DIAMANTE, JUAN BAUTISTA (1640?-1684?), Spanish dramatist, was born at
Castillo about 1640, entered the army, and began writing for the stage
in 1657. He became a knight of Santiago in 1660; the date of his death
is unknown, but no reference to him as a living author occurs after
1684. Like many other Spanish dramatists of his time, Diamante is
deficient in originality, and his style is riddled with affectations;
_La Desgraciada Raquel_, which was long considered to be his best play,
is really Mira de Amescua's _Judía de Toledo_ under another title; and
the earliest of Diamante's surviving pieces, _El Honrador de su padre_
(1658), is little more than a free translation of Corneille's Cid.
Diamante is historically interesting as the introducer of French
dramatic methods into Spain.


DIAMANTINA (formerly called _Tejuco_), a mining town of the state of
Minas Geraes, Brazil, in the N.E. part of the state, 3710 ft. above
sea-level. Pop. (1890) 17,980. Diamantina is built partly on a steep
hillside overlooking a small tributary of the Rio Jequitinhonha (where
diamond-washing was once carried on), and partly on the level plain
above. The town is roughly but substantially built, with broad streets
and large squares. It is the seat of a bishopric, with an episcopal
seminary, and has many churches. Its public buildings are inconspicuous;
they include a theatre, military barracks, hospitals, a lunatic asylum
and a secondary school. There are several small manufactures, including
cotton-weaving, and diamond-cutting is carried on. The surrounding
region, lying on the eastern slopes of one of the lateral ranges of the
Serra do Espinhaço, is rough and barren, but rich in minerals,
principally gold and diamonds. Diamantina is the commercial centre of an
extensive region, and has long been noted for its wealth. The date of
the discovery of diamonds, upon which its wealth and importance chiefly
depend, is uncertain, but the official announcement was made in 1729,
and in the following year the mines were declared crown property, with a
crown reservation, known as the "forbidden district," 42 leagues in
circumference and 8 to 16 leagues in diameter. Gold-mining was forbidden
within its limits and diamond-washing was placed under severe
restrictions. There are no trustworthy returns of the value of the
output, but in 1849 the total was estimated up to that date at
300,000,000 francs (see DIAMOND). The present name of the town was
assumed (instead of Tejuco) in 1838, when it was made a _cidade_.


DIAMANTINO, a small town of the state of Matto Grosso, Brazil, near the
Diamantino river, about 6 m. above its junction with the Paraguay, in
14° 24' 33" S., 56° 8' 30" W. Pop. (1890) of the municipality 2147,
mostly Indians. It stands in a broken sterile region 1837 ft. above
sea-level and at the foot of the great Matto Grosso plateau. The first
mining settlement dates from 1730, when gold was found in the vicinity.
On the discovery of diamonds in 1746 the settlement drew a large
population and for a time was very prosperous. The mines failed to meet
expectations, however, and the population has steadily declined.
Ipecacuanha and vanilla beans are now the principal articles of export.


DIAMETER (from the Gr. [Greek: dia], through, [Greek: metron], measure),
in geometry, a line passing through the centre of a circle or conic
section and terminated by the curve; the "principal diameters" of the
ellipse and hyperbola coincide with the "axes" and are at ...
                          (_continued in volume 8, slice 4, page 0158._)


       *       *       *       *       *


Corrections made to printed original.

DETERMINANT, formula = ab'c" - ab"c' + a'b"c - a'bc" - a"bc' - a"b'c.
changed to = ab'c" - ab"c' + a'b"c - a'bc" + a"bc' - a"b'c.

DETMOLD, added missing comma after 'Detmold possesses a natural history
museum'.

DEVENTER, 'The "Athenaeum" disappeared' corrected from the original
'disappered'.

DEVIL, replaced comma with a period after 'according to 1 Chron. xxi'.

DEVONSHIRE, EARLS AND DUKES OF, 'In November 1684' originally 'Novembr'.

DIAGRAM, 'found to be of use especially' originally 'epsecially'.

DIAL, table angles on the dial, column IX. A.M. III. P.M. bottom entry
corrected from '45 45' to '40 45'.

DIAGRAM, missing closing parenthesis added after 'to mark out by lines'.





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