Title: Hittel on Gold Mines and Mining
Author: Hittell, John S. (John Shertzer), 1825-1901
Language: English
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HITTEL

ON

GOLD MINES

AND

MINING.



QUEBEC:
PRINTED BY G. & G. E. DESBARATS.

1864.



HITTEL
ON
GOLD MINES
AND
MINING.


_Chief Industry._--Mining is the chief industry of California. It
employs more men and pays larger average wages than any other branch of
physical labor. Although it has been gradually decreasing in the amount
of its production, in the profits to the individuals engaged in it, and
in its relative importance in the business of the state, it is yet and
will long continue to be the largest source of our wealth, and the
basis to support the other kinds of occupation.

_Metals obtained._--Our mines now wrought are of gold, silver,
quicksilver, copper and coal. Ores of tin, lead, and antimony in large
veins, beds of sulphur, alum and asphaltum; lakes of borax and springs
of sulphate of magnesia, are also found in the state, but they are not
wrought at the present time, though they will probably all become
valuable in a few years. Platinum, iridium, and osmium are obtained
with the gold in some of the placer mines, but are never found alone,
nor are they ever the main object sought by the miner. The annual yield
of our gold mines is about forty millions of dollars, of our quicksilver
two millions of dollars. Our silver, copper and coal mines have been
opened within a year, and their value is yet unknown. All our other
mining is of little importance as compared with the gold.

_Gold Mines._--Our gold mines are divided into placer and quartz. In
the former, the metal is found imbedded in layers of earthy matter,
such as clay, sand and gravel; in the latter it is incased in veins of
rock. The methods of mining must be adapted to the size of the
particles of gold, and the nature of the material in which they are
found. In placer mining, the earthy matter containing the gold, called
the "pay-dirt," is washed in water, which dissolves the clay and
carries it off in solution, and the current sweeps away the sand,
gravel and stones, while the gold, by reason of the higher specific
gravity, remains in the channel or is caught with quicksilver. In
quartz mining the auriferous rock is ground to a very fine powder, the
gold in which is caught in quicksilver, or on the rough surface of a
blanket, over which the fine material is borne by a stream of water.
About two-thirds of our gold is obtained from the placers, and
one-third from the quartz.

A mine is defined and generally understood to mean "a subterraneous
work or excavation for obtaining metals, metallic ores or mineral
substances;" but this definition does not apply to our placer mines,
which are places where gold is taken from diluvial or alluvial
deposits. Most of the work is not subterraneous; it is done in the full
light of day. In some of the claims the pay-dirt lies within two feet
of the surface; in others it lies much deeper, but all the
superincumbent matter is swept away.

Water is the great agent of the placer miner; it is the element of his
power; its amount is the measure of his work, and its cost is the
measure of his profit. With an abundance of water he can wash every
thing; without water he can do little or nothing. Placer mining is
almost entirely mechanical, and of such a kind that no accuracy of
workmanship or scientific or literary education is necessary to mastery
in it. Amalgamation is a chemical process it is true, but it is so
simple that after a few days' experience, the rudest laborer will
manage it as well as the most thorough chemist.

It is impossible to ascertain the amount of gold which has been taken
from the mines of California. Records have been kept of the sums
manifested at the San Francisco Custom House, for exportation, and
deposited for coinage in the mints of the United States; and there is
also some knowledge of the amounts sent in bars and dust to England;
but we have no account of the sums carried by passengers to foreign
countries and coined elsewhere than at London, or used as jewelry, or
of the amount now in circulation in this state. According to the books
of the Custom House of San Francisco, the sums manifested for export
were as follows:

In 1849, $4,921,250; in 1850, $27,676,346; in 1851, $42,582,695; in
1852, $46,586,134; in 1853, $57,331,034; in 1854, $51,328,653; in 1855,
$45,182,631; in 1856, $48,887,543; in 1857, $48,976,697; in 1858,
$47,548,025; in 1859, $47,640,462; in 1860, $42,303,345; in 1861,
$40,639,089; a total of $551,603,904 in twelve years.

The exportation of gold commenced in 1848, but we have no record of the
sums sent away in that year. Previous to 1854 very large sums were
carried away by passengers, who gave no statement at the Custom House;
since that year, the manifests show the exportation correctly within a
few millions. I am entirely satisfied that the total gold yield of
California has been not less than seven hundred millions of dollars;
but I have not room here to state the reasons for this opinion. My
estimate is considerably less than that of most business men of the
state, and less than that made by Hunt's _Merchants' Magazine_. There
was undoubtedly a regular increase in the annual yield of the mines
from 1848 to the end of 1853; and there has been a gradual decrease
since the beginning of 1854--a decrease perhaps not very regular but
still certain. Since 1854 considerable sums exported from San
Francisco, and included in our tables, came from mines beyond the
limits of California, such as the mines in Southern Oregon, in the
eastern part of Washington Territory, in British Columbia, and in
Nevada Territory; and while the California gold yield has been
decreasing, these extraneous supplies have been increasing. Several
millions must be deducted from the annual shipments since 1858, for
foreign gold. The gold yield will undoubtedly continue to fall, but to
what point and at what rate no one can know. I believe that in 1870,
the yield will not exceed thirty millions of dollars.

_Placer Mines._--Placer mines are divided into many classifications.
The first and most important is into deep and shallow. In the former
the pay-dirt is found deep, twenty feet or more beneath the surface; in
the latter, near the surface. The shallow or surface diggings are
chiefly found in the beds of ravines and gullies, in the bars of
rivers, and in shallow flats; the deep diggings are in hills and deep
flats. The pay-dirt is usually covered by layers of barren dirt, which
is sometimes washed, and sometimes left undisturbed, while the pay-dirt
is taken out from beneath it through tunnels or shafts. So far as our
present information goes, we have reason to believe that no gold
country ever possessed so large an extent of paying placer mines, with
the pay-dirt so near the surface, and with so many facilities for
working them as California. In Australia the diggings are very deep and
spotted, that is, the gold is unevenly distributed, and the supply of
water for mining is scanty. In Siberia the winter is terribly cold
during six months of the year. In Brazil the diggings were not so
extensive nor so rich as in this state. Here we have numerous large
streams coming down through the mining districts, very large bodies of
pay-dirt, and a mild climate.

After dividing placers into deep and shallow, the next classification
will be according to their topographical position, as into hill, flat,
bench, bar, river-bed, ancient river-bed, and gulch mines. Hill
diggings are those where the pay-dirt is in or under a hill. Flat
diggings are in a flat. Bench diggings are in a "bench" or narrow table
on the side of a hill above a river. Benches of this kind are not
uncommon in California, and they often indicate the place where the
stream ran in some very remote age. Bars are low collections of sand
and gravel at the side of a river and above its surface at low water.
River-bed claims are those beneath the surface of the river at low
water, and access is obtained to them only by removing the water from
the bed by flumes or ditches. Ancient river-bed claims are those of
which the gold was deposited by streams in places where no streams now
exist. Gulch claims are those in gullies which have no water, save
during a small part of the year. A "claim" is the mining land owned or
held by one man or a company.

The placer mines are again classified according to the manner in which,
or the instruments with which they are wrought. There are sluice
claims, hydraulic claims, tunnel claims, dry washing, dry digging, and
knife claims. In 1849 and 1850, the main classification of the placers
was into wet diggings and dry diggings, the former meaning mines in the
bars and beds of rivers, and dry diggings were those in gullies and
flats where water could be obtained only part of the year or not at
all. That classification was made while nearly all the mining was done
near the surface, before the great deposits of pay-dirt in the hills
had been discovered, and before ditches, sluices, and the hydraulic
process had been introduced. The class of mines then known as the "dry
diggings," and which for several years furnished nearly half of the
gold yield of the state, are now, with a few unimportant exceptions,
exhausted, or left to the attention of the Chinamen.

The purpose of all placer miners is not to catch all the gold in the
dirt which they wash, but to catch the greatest possible quantity
within a given time. It is not supposed that any process used in gold
mining catches all the metal. Part of it is lost; in some processes a
considerable proportion. The general estimate in California is, that
one-twentieth of the gold in the dirt which is washed is lost. Many of
the particles are so very small as to be invisible to the naked eye,
and so light that their specific gravity does not avail to prevent them
from being carried away by the water like sand. The larger pieces will
sink to the bottom and resist the force of the water; the smaller the
particles, the greater the danger that it will be borne away. Many
devices have been tried to catch all the gold, but none have succeeded
perfectly, and some which have caught a portion of what escaped from
the ordinary modes of mining, have been found to cost more than their
yield. The miner does not grieve about that which he cannot catch. He
is not careful to catch all that he could. His purpose is to draw the
largest possible revenue per day from his claim. He does not intend to
spend many years in mining, or if he does, he has become thriftless and
improvident. In either case, he wishes to derive the utmost immediate
profit from his mine. If his claim contain a dollar to the ton, and he
can save five dollars by slowly washing only six tons in a day, while
he might make ten dollars by rapidly washing fifteen tons in a day, he
will prefer the latter result, though he will loose twice as much of
the precious metal by the fast as by the slow mode of working. The
object of the miner is the practical dispatch of work, and his success
will depend to a great extent upon the amount of dirt which he can wash
within a given space of time. He regrets that any of the gold should be
wasted, but his regret is because it escapes from his sluice and his
pocket, rather than because it is lost to industry and commerce.

_The Sluice._--The board-sluice is a long wooden trough, through which
a constant stream of water runs, and into which the auriferous dirt is
thrown. The water carries away the clay, sand, gravel and stones, and
leaves the gold in the bottom of the sluice, where it is caught by its
gravity and by quicksilver. The board-sluice is the great washing
machine, and the most important instrument used in the placer mining of
California. It washes nearly all the dirt and catches nearly all the
placer gold of the country. It was invented here, although it had
previously been used elsewhere; it has been more extensively employed
here than in any other country, and it can be used here to more
advantage than elsewhere. It is not less than fifty feet long, nor less
than a foot wide, made of boards. The width is usually sixteen or
eighteen inches; and never exceeds five feet. The length is ordinarily
several hundred and sometimes several thousand feet. It is made in
sections or "boxes" twelve or fourteen feet long. The boards are an
inch and a half thick, and are sawn for that special purpose, the
bottom boards being four inches wider at one end than the other. The
narrow end of one box therefore fits in the wide end of another, and in
that way the sluice is put together, a long succession of boxes, the
lower end of each resting in the upper end of another, and not fastened
together otherwise. These boxes stand upon trestles, with a descent
varying from eight to eighteen inches in twelve feet. It is therefore
an easy matter to put up or take down a sluice after the boxes are
made, and it is not uncommon for the miners to haul their boxes from
one claim to another. The descent of a sluice is usually the same
throughout its length, and is called its "grade." If there be a fall of
eight inches in twelve feet, the sluice has an "eight-inch grade," and
if the fall be twice as great, it is a "sixteen-inch grade." The grade
depends upon the character of the pay-dirt, the length of the sluice,
and its position. The steeper the descent, the more rapidly the dirt is
dissolved, but the greater the danger also that the fine particles of
gold will be carried away by the water. The tougher the dirt, that is,
the greater its resistance to the dissolving power of the water, the
steeper, other things being equal, should be the sluice. A slow current
does not dissolve tough clay, and that is the greater part of the
pay-dirt, so rapidly as a swift one. The shorter the sluice, other
things being equal, the smaller the grade should be. There is more
danger that the fine particles of gold will be lost by a short sluice
than by a longer one, and to diminish this danger, the rapidity of the
current must be reduced by a small grade. The greater the amount of
dirt to be washed, other things being equal, the steeper should be the
grade; for a swift current will wash more dirt than a slow one. In many
claims the pay-dirt is full of large stones and boulders, weighing from
one hundred to five hundred pounds each, all of which must be carried
away through the sluice. Some are sent down whole, and others are
broken into pieces with sledge hammers before they are thrown into the
box. These require a swift current and a large body of water. The
larger the supply of water, the steeper the sluice is made, other
things being equal. Of course economy and convenience of working
require that the sluice should be near the level of the ground, and as
that may be steep or level below the claim, the grade of the sluice
must to some extent conform to it. There are thus a multitude of points
to be taken into consideration in fixing the grade of a sluice; but a
fall of less than eight or more than twenty inches, in a box of twelve
feet, would be considered as unsuitable for the board-sluice. Sometimes
the upper part of the sluice is made steeper so as to dissolve the
dirt, and the lower part has a small grade to catch the gold. The
clayey matter of ordinary pay-dirt is fully dissolved in a sluice two
hundred feet long with a low grade, so the use of the boxes beyond that
length is merely to catch the gold. There are claims however in which
the clay is so extremely tough that it will roll in large balls more
than a quarter of a mile through a steep sluice with a large head of
water, and come out at the lower end scarcely diminished in size.

The gold is caught in the sluice-boxes by false bottoms of various
kinds. It would not do to leave the smooth boards, for the water would
sweep all the gold away, and the boards themselves would soon be worn
through. The most common false bottom is the longitudinal riffle-bar,
which is from two to four inches thick, from three to seven inches
wide, and six feet long. Two sets of these riffle-bars go into each
sluice-box, the box being twice as long as the bar. A set of
riffle-bars is as many as fill one half of a box. They are wedged in,
from an inch to two inches apart; the wedging being used, because the
bars can more readily be fastened in their places, and more easily
taken up, than if nails were used. Before the work of sluicing
commences, all the boxes are fitted with riffle-bars, and the bottom of
the sluice is therefore full of holes from one to two inches wide, from
three to seven inches deep, and six feet long. These are the places in
which the gold, quicksilver, and amalgam are caught. Quicksilver is
used now in nearly all the sluices, and is the more necessary the
smaller the particles of gold. The large pieces of the metal would all
be caught by their specific gravity without the aid of amalgamation.

The sluice-boxes having been made, and set up with the proper grade,
the water is turned in. The boxes are made of the rough boards as they
come from the saw, and the joints are not waterproof, but the leaks are
soon stopped by the swelling of the wood, or by the dirt. The stream of
water in the sluice is at least two inches deep over the bottom. The
height of the sides of the boxes is from eight inches to two feet. The
sluice usually runs through the claim, and the auriferous dirt is
thrown in with shovels, of which from four to twenty are constantly at
work. A man will throw in from two to five cubic yards of dirt in one
day. The water rushing over the dirt as it lies in the box, rapidly
dissolves the clay and loam, and then sweeps the sand, gravel and
stones down. The first dirt in the box goes to fill the spaces between
the riffle-bars. After the sluicing has been in progress a couple of
hours, some quicksilver is put in at the head of the sluice, and it
gradually finds its way downward, most of it stopping, however, near
where it is put in.

_Amalgamation._--There are a few metals, including gold, silver, copper
and tin, which, with quicksilver, form a peculiar chemical union called
amalgamation, a process of great importance to the gold miner. When a
piece of gold or silver is placed in mercury, the latter metal
gradually penetrates through it, destroys the coherence of its
particles, and form with it a mass like dough. A lump of gold as large
as a bean will be soaked through in three or four days; with silver and
copper the process is slower, but they are affected in the same manner.
Amalgamation, though a union of a solid with a liquid, differs much
from a solution. In the latter the union is mechanical; in the former
it is chemical. In the latter the solid is reduced to particles of
impalpable fineness; in the former it is not. An ounce of salt will be
dissolved in, and nearly equally diffused through, a pint of water; but
if an ounce of gold be thrown into a pint of quicksilver, it will,
after forming an amalgam with the quicksilver, remain at the bottom. We
have no texture so fine that it will strain salt out of water; but the
particles of gold are so coarse in amalgam that they can easily be
strained out by means of buckskin or tight cloths. However, a little
gold will remain in the quicksilver--about the fiftieth part of an
ounce of gold in every pound of quicksilver; and the only method of
obtaining this gold is by retorting.

Quicksilver is used in gold mining for catching the small particles of
metal; the large ones are caught by their weight. But many of the
particles are so small that they are almost invisible to the naked eye,
and when in moving water they float. Miners frequently show visitors
the fineness of their gold by putting some of the dust in a vial with
water, and upon shaking, the particles of metal can be seen floating
about in the clear water. Riffles, and all the devices to get the
benefit of specific gravity, are of little use to arrest this
"float-gold," so amalgamation is employed. If a bit of quicksilver is
put in the way of the fine gold, the two metals unite at once and make
a larger bulk, which can be caught.

There is no such attraction between gold and quicksilver as there is
between the magnet and iron; but when the two former metals once touch,
an amalgam is immediately formed, and if the proportions of the metals
be about even, they in time make a hard mass. Some gold does not
amalgamate readily; in various diggings of Siskiyou county, the gold
has a reddish coating, which prevents amalgamation. Grease or resin in
the water used for washing, is also unfavorable. So is cold. Heat is
favorable, and therefore less gold is lost in summer than in winter.
Quicksilver that has been once used is considered better than that
fresh from the flask.

No tinned iron or copper vessel should be used for holding or panning
out amalgam, or dirt containing amalgam; since quicksilver forms an
amalgam with tin and copper, and will stick to the sides of a tinned or
copper pan.

In most sluices, the quicksilver is put in above the riffle-bars at
various places along in the boxes, with a confidence that the great
specific gravity of the metal will prevent it from being lost. The
greater the quantity and proportion of fine gold, the greater the
importance of the quicksilver.

The best method of catching very fine gold by amalgamation is to cover
a large copper plate with mercury, and let the dirt and water, in a
thickness of not more than a quarter of an inch, pass over it slowly.
There are various methods of covering copper plates with quicksilver.
The first thing, in every case, is to wash the copper with diluted
nitric acid, so as to remove all dirt and grease. The quicksilver may
then be rubbed on with a rag; or, still better, it may be dissolved in
nitric acid, and the liquid nitrate of quicksilver may be applied with
a rag. The nitric acid will attack the copper, and leave the
quicksilver as an amalgam on the surface of the copper. This is the
most common process, but the nitrate of copper continues for a long
time to come up through the quicksilver and interfere with the catching
of the gold. When the nitrate of copper appears--it is a green
slime--it should be scraped off and the place rubbed over with
quicksilver. When a plate is once covered with mercury, the operation
need never be repeated; but more mercury must be sprinkled on as the
gold collects and forms a solid amalgam. The plate is usually three
feet wide and six feet long, and is set nearly level. In very large
sluices the stream should be divided so as to run over different
plates. The slowness of the current and the shallowness of the water
are important, for with a swift current or deep water many of the
particles of float-gold may escape without touching the quicksilver.
Wherever a speck of gold has fixed itself on the plate, there others
will collect about, evidently preferring to fix themselves in a
neighborhood rather than in a waste place. The more gold there is on a
plate, the better it is considered to be. The seasons for cleaning up
are usually determined by the danger of theft. Miners do not like to
leave their gold out in quantities so large as to attract thieves. The
amalgam is sometimes half an inch thick, and is usually, at cleaning-up
time, a hard mass, which must be loosened by heat. The plate is put on
a fire, and when it gets so warm that the hand can scarcely bear it,
the amalgam is softened and loosened, so that it can be scraped off
readily. The plate is then sprinkled anew with quicksilver, and is
ready for use again. Mercury does not amalgamate with copper so readily
as with gold or silver. A copper plate, the sixteenth of an inch thick,
may be used for at least five years, and perhaps for ten; whereas a
gold plate of equal thickness would, if exposed to the action of
quicksilver in the same manner, fall to pieces in a few weeks. After a
time the quicksilver pervades the copper, and gives it a silvery
whiteness all through on the under side. It is said that a solution of
cyanuret or prussiate of potash, is used instead of nitric acid in
applying mercury to copper plates, and that it is still better, there
being then no trouble with the green spots of nitrate of copper.

A good amalgamated copper plate is considered as serviceable as a bed
of quicksilver of equal size, and it is very much cheaper and more
convenient to manage.

The dirt and water should be admitted to the copper plate, by falling
first through a sheet-iron plate, pierced with holes half an inch long
and a sixteenth of an inch wide. Some miners place this sheet-iron
plate immediately over the copper.

Very soon after the water and dirt commence to run in the sluice, all
the spaces between the riffle-bars are filled with sand, gravel and
dirt; which, however, present many little inequalities of surface,
sufficient to catch all the particles of gold larger than a pin-head.
The largest gold is caught near the head of the sluice; and the farther
down the sluice, the finer the gold. In some sluices, where the
pay-dirt contains much coarse gold, the quicksilver is introduced from
thirty to sixty yards below the head, so as to catch only the fine
particles of metal.

_Cleaning up._--The separation of the gold, amalgam, and quicksilver,
from the dirt in the bottom of the sluice, is called "cleaning up;" and
the period between one "cleaning up" and another is called a "run." A
run in a common board-sluice usually lasts from six to ten days.
Ordinarily the sluice runs only during daylight, but in some claims the
work continues night and day. Cleaning up occupies from half a day to a
day, and therefore must not be repeated too often, because it consumes
too much time. In some sluices the cleaning up does not occur until the
riffle-bars have been worn out or much bruised by the wear of the
stones and gravel. Cleaning up is considered light and pleasant work as
compared with other sluicing, and is often reserved for Sunday. At the
time fixed, the throwing in of dirt ceases, and the water runs until it
becomes clear. Five or six sets of riffle-bars, a distance of thirty or
thirty-five feet, are taken up at the head of the sluice, and the dirt
between the bars is washed down, while the gold and amalgam lodge above
the first remaining set of riffle-bars, whence it is taken out with a
scoop or large spoon, and put into a pan. Five or six more sets of bars
are taken up, and so on down. Sometimes all the riffle-bars are taken
up at once, save one set in every thirty-six feet, and then the work of
cleaning up is dispatched much more rapidly.

The quicksilver and amalgam taken from the sluice are put into a
buckskin or cloth, and pressed, so that the liquid metal passes
through, and the amalgam is retained. The amalgam is then heated, to
drive off the mercury. This may be done either in an open pan or in a
close retort. In the former, the quicksilver is lost; in the latter, it
is saved. The pan is generally preferred. Often a shovel or plate of
iron is used. Three pounds of amalgam, from which the liquid metal has
been carefully pressed out, will yield one pound of gold. The gold
remaining after the quicksilver has been driven off by heat from the
amalgam, is a porous mass, somewhat resembling sponge-cake in
appearance.

_Riffle-Bars._--The riffle-bars are usually sawn longitudinally with
the grain of the wood, but "block riffle-bars" are considered
preferable; the latter are cut across the tree, and the grain stands
upright in the sluice-box. The block riffle-bars are three times more
durable than the longitudinal; and as the latter kind are worn out in a
week in some large sluices, there is a considerable saving in using the
former. The block riffle-bars are only two or three feet long.

In some small sluices the riffle-bars are not placed in the boxes
longitudinally, nor in sets; but one bar near the head runs downward at
an angle of forty-five degrees to the course of the box, not touching
its lower end to the side of the box, but leaving an open space of an
inch there. Just below this open space another bar starts from the side
of the box and runs downward at right angles to the course of the first
bar, and an open space is again left at the end of this bar; and so on
down to near the lower end of the sluice, where there are longitudinal
riffle-bars in sets as described in the preceding paragraphs. The
consequence of using this kind of riffle-bar is, that though much of
the water and light dirt runs straight over the bars, the heavier
material runs down from side to side in a zigzag course. Near the head
of the sluice is a vessel, from which quicksilver falls by drops into
the box; and it follows the course of riffle-bars, overtaking the gold
which takes the same route. These zigzag riffle-bars are nailed down.
In all sluices, men must keep watch to see that the boxes do not choke;
that is, that the dirt and stones do not collect in one place, so as to
make a dam, and cause the water to run over the sides, and thus waste
the gold.

There are small sluices, from which all stones as large as a doubled
fist are thrown out. For this purpose the miner uses a sluice-fork,
which is like a large manure-fork or garden-fork, but has tines which
are blunt and of equal width all the way down; the bluntness being
intended to prevent the tines from catching in the wood, and the
equality of width to prevent the stones from getting fast in the fork.

In some sluices, the "block riffle-bars"--that is, bars cut across the
grain of the tree--are set transversely in the boxes, and about two
inches apart.

Another device is, to fill the pores of such riffle-bars with
quicksilver. This is done by driving an iron cylinder with a sharp edge
into the surface of the bar, then putting mercury into the cylinder,
and pressing it into the wood. The quicksilver, thus fastened in the
wood, catches particles of gold, which must be scraped off when the
time for "cleaning up" comes.

_Double Sluices._--Sluices are sometimes made double--that is, with a
longitudinal division through the middle, so that there are two
distinct sluice-boxes side by side. Two companies may be working side
by side, so that it will be cheaper for them to build their sluices
jointly. In some places the amount of water varies greatly; so that in
the winter there is enough to run two sluices, and in the summer only
one. And there are companies which wish to continue washing without
interruption; so they wash first on one side and then on the other, and
clean up without any interruption to the process of washing.

Another device for saving gold in sluices is the "under-current box."
There is a grating of iron bars in the bottom of a box, near the lower
end of a sluice; and under this grating is another sluice, with an
additional supply of clean water, and with a lower grade. The grating
allows only the fine material to fall through; and the current of water
being moderate, many particles of gold, that would otherwise be lost,
are saved. Sometimes the matter from the under-current box is led back
to the main sluice.

_Rock-Sluices._--Large sluices are frequently paved with stone, which
makes a more durable false bottom than wood, and catches fine gold
better than riffle-bars. The stone bottoms have another advantage--that
it is not so easy for thieves to come and clean up at night, as is
often done in riffle-bar sluices. But, on the other hand, cleaning up
is more difficult and tedious in a rock-sluice, and so is the putting
down of the false bottom after cleaning up. The stones used are
cobbles, six or eight inches through at the greatest diameter, and
usually flattish. A good workman will pave eight hundred square feet of
sluice-box with them in a day; and after the water and dirt have run
over them for an hour, they are fastened very tightly by the sand
collected between them. In large sluices, wooden riffle-bars are worn
away very rapidly--the expense amounting sometimes, in very large and
long sluices, to twenty or thirty dollars a day; and in this point
there is an important saving by using the stone bottoms. They are used
only in large sluices, and they generally have a grade of twelve or
fourteen inches to the box of twelve feet.

_Hydraulic Mining._--After the board-sluice, with its various adjuncts
of riffle-bars, stone bottoms, copper plates, and so forth, the next
instrument of importance in the gold-mining of California, is the
hydraulic hose, used to let water down from a considerable height, and
throw it under the pressure of its own weight against the pay-dirt,
which is thus torn down, broken up, dissolved and carried into the
sluice below. The sluice is a necessary part of hydraulic mining. The
hose is used, not to wash the dirt, but to save digging with shovels,
and to carry it to the sluice.

The hydraulic process is applied only in claims where the dirt is deep
and where the water is abundant. If the dirt were shallow in the claim
and its vicinity, the necessary head of water could not be obtained.
Hydraulic claims are usually in hills. The water is led along on the
hill at a height varying from fifty to two hundred feet above the
bed-rock, to the claim at the end or side of the hill, where the water,
playing against the dirt, soon cuts a large hole, with perpendicular or
at least steep banks. At the top of the bank is a little reservoir,
containing perhaps not more than a hundred gallons, into which the
water runs constantly, and from which the hose extends down to the
bottom of the claim. The hose is of heavy duck, sometimes double, sewn
by machine. This hose when full is from four to ten inches in diameter,
and will bear a perpendicular column of water fifty feet high; but a
greater height will burst it. Now, as the force of the stream increases
with the height of the water, it is a matter of great importance to
have the hose as strong as possible; and for this purpose, in some
claims, it is surrounded by iron bands, which are about two inches
wide, and are connected by four ropes which run perpendicularly down.
The rings are about three inches apart. The "crinoline hose," thus
made, is very flexible, and will support a column of water one hundred
and fifty or two hundred feet high. The pipe at the end of the hose is
like the pipe of a fire-engine hose, though usually larger. Sometimes
the pipe will be eight inches in diameter where it connects with the
hose, and not more than two inches at the mouth; and the force with
which the stream rushes from it is so great, that it will kill a man
instantaneously, and tear down a hill more rapidly than could a hundred
men with shovels.

One or two men are required to hold the pipe. They usually turn the
stream upon the bank near its bottom until a large mass of dirt tumbles
down, and then they wash this all away into the sluice; when they
commence at the bottom of the bank again, and so on. If the bank is one
hundred and fifty feet high, the mass of earth that tumbles down is of
course immense, and the pipemen must stand far off, for fear that they
will be caught in the avalanche. Such accidents are of daily
occurrence, and the deaths from this cause probably are not less than
threescore every year in the state. Often legs are broken; still more
frequently the pipemen have warning, and escape in time. When men are
buried in the falling dirt, the water is used to wash them out. In some
claims, the pipe will tear down more dirt than the sluice can wash; in
other claims, the sluice always demands more dirt than the pipe can
bring down. In the latter case, blasting may be used to loosen the
dirt, or the miners may undermine the bank, leaving a few columns of
dirt for support; and then these being washed away by the pipe, the
whole bank comes tumbling down.

In hydraulic claims, all the dirt is washed; in all other kinds of
claims, such dirt as contains no gold is thrown to one side, or
"stripped off." "Hydraulic mining" is the highest branch of placer
mining; it washes more dirt, and requires more water, and a larger
sluice, than any other kind of mining. The number of men employed in a
hydraulic claim, however, is usually small, from three to six, the
water doing nearly all the work. In some claims a man is constantly
employed with a heavy sledge-hammer in breaking up large stones, so
that the pieces may be sent down the sluice. One man attends to the
sluice, and sees that the dirt does not choke up in the sluice, or in
the claim above it.

The quantity of dirt that can be washed with a hydraulic pipe depends
upon various circumstances--such as the supply of water, the height of
its fall, the toughness of the dirt, and the amount of moisture in it.
More can be washed in winter than in summer, because the dirt is then
moister, and requires less water to loosen and dissolve it. The
quantity of water used in a hydraulic claim is from forty to two
hundred inches. With one hundred inches, at least thirty cubic yards
can be washed in ten hours, on an average; and three men can do all the
work. If there were a cent's worth of gold in each cubic foot, the
thirty cubic yards would yield eight dollars and ten cents per day, or
two dollars and seventy cents to the man, exclusive of the cost of
water. But, as a matter of fact, nearly all the hydraulic claims pay
more than that, and they will average at least three cents to the cubic
foot, and many of them yield five cents. The water usually costs twenty
cents an inch per day, so that one hundred inches would cost twenty
dollars. Allowing for the water at that rate, a claim in which thirty
cubic yards could be washed in a day with one hundred inches of water,
and in which the dirt contained five cents to the cubic foot, would
leave a net pay of six dollars and sixty-six cents to each man per day.

One hydraulic company, of whose labors I have a note, washed two
hundred and twenty-four thousand cubic feet of dirt in six days, using
two hundred inches of water, and employing ten men. The wages of the
men amounted, at four dollars per day each, to two hundred and forty
dollars; the water cost three hundred dollars; and the waste of
quicksilver, and wear of sluice, perhaps one hundred dollars more,
making a total expenditure of six hundred and forty dollars: and the
gold obtained was three thousand dollars, leaving a clear profit of
twenty-three hundred and fifty dollars. The dirt contained one cent and
a fifth of gold in a cubic foot. The greater the amount of water used,
the greater the proportionate amount of dirt that can be washed, and
the greater the proportionate profits. It is far more profitable to
have a large sluice than a little one, if the water and dirt can be
obtained in abundance.

Usually, in a hydraulic claim, the dirt is washed down to the bed-rock;
but in some places the washing stops far above the bed-rock, because
there is no outlet for the water.

_Blasting._--In some hydraulic claims, the dirt, in dry seasons, is
blasted, so as to loosen it. A drift or hole is cut into the bottom of
a hill, one or two hundred feet high, and a number of kegs of powder
(from twenty to two hundred) are introduced, and they are fired with a
slow match. The explosion makes an earthquake in the vicinity; and the
ground is loosened to such an extent that there is a great saving of
labor. The breaking up of the dirt and the exposure to the air are
supposed to facilitate the washing greatly.

More water is required for piping down banks than for washing the dirt;
and often the sluice is almost idle for want of dirt, while the water,
after being thrown against the hillside, runs away without doing any
service at washing. Blasting, therefore, by loosening the earth,
enables the hydraulic miner to have an abundant and regular supply of
dirt in his sluice, at an expense much less than the cost of manual
labor to dig the bank down with pick and shovel.

_Tail-Sluice._--The tail-sluice is a large sluice made for rewashing
the tailings or dirt which has previously passed through other sluices.
It is placed ordinarily in the bed of a ravine or creek through which
tailings run, and it receives no attention for weeks or months at a
time, save to keep it from choking. The sluices emptying into it
furnish both dirt and water, and in the dirt there is always a large
amount of fine gold, as is plainly proved by the fact that some of the
tail-sluices have paid large profits to their owners. Tail-sluices are
always large, long and paved with stones; and sometimes they are
double, so that one side may be cleaned up while the other continues
washing. In a branch of the Yuba there is, or was not long since, a
tail-sluice twenty feet wide.

_Tunnel-Sluice._--A tunnel-sluice is a sluice in a tunnel. It sometimes
happens that a considerable body of water runs out through a tunnel;
and in such case, a sluice at the bottom of the tunnel offers the
easiest method of getting out and washing the dirt. The tunnels are
never cut level, but with a slightly ascending grade, so that the water
will always run out. The grade is so low, that transverse riffle-bars
must be used; for with longitudinal riffle-bars or stones, there would
be too much danger of choking. These tunnel-sluices, because of their
low grades, require much more attention than any other kind of sluices.

_Ground Sluice._--All the sluices hitherto mentioned and described have
wooden boxes, but the ground-sluice has no box: the water runs on the
ground. The place selected for the ground-sluice is some spot where
there is a considerable supply of water, a steep descent for it, and
much poor dirt. The stream is turned through a little ditch, which the
miners labor to deepen and enlarge, and when it is deep they prize off
the high banks so that the dirt may fall down into the ditch. This is a
very cheap and expeditious way of washing, but it is not applied
extensively. It is used to the most advantage for washing where the
water is abundant for only a few weeks after heavy rains, and where it
would not pay to erect large sluices. A few cobble-stones should be
left or thrown at intervals in the bed of the ground-sluice to arrest
the gold, for if the bed were smooth clay, the precious metal might all
be carried off. Quicksilver is not used in the ground-sluice. After the
dirt has all been put through the ground-sluice, it is cleaned up in a
short board-sluice, or a tom.

_Long Tom._--The tom or long tom, an instrument extensively used in the
Californian mines in 1851 and 1852, but now rarely seen, is a wooden
trough about twelve feet long, eighteen inches wide at the upper end,
and widening at the lower to thirty inches, with sides eight inches
high. It is used like a board-sluice, but has no riffle-bars, and at
the lower end its bottom is of sheet-iron, perforated with holes half
an inch in diameter. This sheet-iron is turned up at the lower end, so
that the water never runs over there, but always drops down through the
perforated sheet-iron or riddle, into a little riffle-box, containing
transverse riffle-bars. A stream of water of about ten inches makes a
"tom-head"--or the amount considered necessary for a tom--through the
tom, which has a grade similar to that of a board-sluice. The dirt is
thrown in at the head of the tom, and a man is constantly employed in
moving the dirt with a shovel, throwing back such pieces of clay as are
not dissolved, to the head of the tom, and throwing out stones. From
two to four men can work with a tom; but the amount of dirt that can be
washed is not half that of a sluice. The tom may be used to advantage
in diggings where the amount of pay-dirt is small and the gold coarse.
The riffle-box contains quicksilver, and as the dirt in it is kept
loose by the water falling down on it from the riddle above, a large
part of the gold is caught; but where the particles are fine, much must
be lost.

_Cradle._--The rocker or cradle is still less than the tom and inferior
in capacity. It bears some resemblance in shape and size to a child's
cradle, and rests upon similar rockers. The cradle-box is about forty
inches long, twenty wide, and four high, and it stands with the upper
end about two feet higher than the lower end, which is open so that the
tailings can run out. On the upper end of the cradle-box stands a
hopper or riddle-box twenty inches square, with sides four inches high.
The bottom of this riddle box is of sheet-iron, perforated with holes
half an inch in diameter. The riddle-box is not nailed to the
cradle-box, but can be lifted off without difficulty. Under the riddle
is an "apron" of wood or cloth, fastened to the sides of the cradle-box
and sloping down to the upper end of it. Across the bottom of the
cradle-box are two riffle-bars about an inch square, one in the middle,
the other at the end of the box. The dirt is shovelled into the hopper,
the "cradler" sits down beside his machine, and while with one hand
with a ladle he pours water from a pool at his side upon the dirt, with
the other he rocks the cradle. With the water and the motion the dirt
is dissolved, and carried down through the riddle, falling upon the
apron which carries it to the head of the cradle-box, whence it runs
downward and out, leaving its gold, black sand, and heavier particles
of sand and gravel behind the riffle-bars. The man who rocks a cradle
learns to appreciate the fact, that the "golden sands" of California
are not pure sand, but are often extremely tough clay, a hopperful of
which must be shaken about for ten minutes before it will dissolve
under a constant pouring of water. Many large stones are found in the
pay-dirt. Such as give an unpleasant shock to the cradle, as they roll
from side to side of the riddle-box, are pitched out by hand, and after
a glance to see that no gold sticks to their sides, are thrown away;
but the smaller ones are left until the hopperful has been washed, so
that nothing but clean stones remain in the riddle, and then the
cradler rises from his seat, lifts up his hopper, and with a jerk
throws all the stones out. The water and the rocking are both
necessary. Without the water, the dirt could not be washed; and without
the rocking, the dirt would dissolve very slowly, and the gold would
most of it be lost. The rocking keeps the dirt in the bottom of the
cradle more or less loose, so that the particles of gold can sink down
in it, whereas if the cradle stood still, the sand there would almost
immediately pack down into a hard floor, over which the gold would run
almost as readily as over a board. The whole business of washing with a
cradle, is a repetition of the process already described--some dirt,
about one-third or one-fourth of what the hopper would hold, if full,
is put into the hopper, and while the cradle is rocked with one hand,
the other pours in the water. The cradle is cleaned up two or four
times in a day. The cleaning up is done by lifting the hopper, taking
out the apron, scraping up all the dirt in the bottom of the cradle
with an iron spoon, putting it into a pan and washing out the dirt, so
that only the gold will be left. This last process is called panning
out, and will be described in the next section. Most of the gold
collects above the upper riffle-bar, including all the larger lumps. If
the apron be of rough woollen cloth, some of the fine gold will be
caught there. In diggings where the gold is very fine, the hopper is
sometimes placed over the lower end of the cradle, and the apron is
made twice as long, and with a lower inclination than in the more
common form of the rocker. The water for the cradle should be supplied
by a little ditch, with a reservoir at the head of the cradle, to
contain five or six gallons. The dipper should be of tin, shaped like a
basin, hold about a gallon when full, and have a handle an inch and a
half in diameter, and eight inches long. The difference of height
between the upper and lower ends of the cradle should not be more than
two inches: a steeper inclination will make the current running through
it too strong, and the gold will be carried off; and, on the other
hand, if the cradle be nearer a level it will be hard to rock, and the
dirt in the bottom will pack more rapidly. The amount of dirt that can
be washed in a day with a cradle, varies from one to three cubic yards.
The dirt is usually shovelled into a pan or bucket, from which it is
thrown into the hopper. The miners usually measure the amount of dirt
washed by the number of "pans." One man working alone with a cradle
ought to wash from seventy-five to one hundred and fifty pans in a day,
and two men will wash twice as much. A pan may contain one-third or
one-half of a cubic foot. Two men can work more conveniently with the
rocker than one. There is enough work to give constant employment to a
cradler and a shoveller. The latter has a couple of buckets or pans,
which he fills alternately, always keeping one full and near the
cradler, so that without moving his feet he can pick it up and empty it
into the riddle-box. If the rocker have only one man, he must stop
rocking after washing every pan and get more dirt. This delay is
injurious to the process of washing, because it allows the dirt in the
bottom of the cradle to harden and pack, and some gold is always lost
as a consequence. If the dirt and water be convenient, not more than
two men can work to a profit with a rocker. But sometimes it happens
that water cannot be led to the claim, and in such case the dirt must
be carried to the water, a greater weight of which is used than of
dirt. At least three times as much water as dirt is required for
washing. If the distance from the hole to the water be not over ten or
twenty feet, the miners will usually carry the dirt in buckets; if
farther they will use wheelbarrows; and sometimes for greater distances
pack-mules or waggons. The greater the distance, the more the men
required for carrying the dirt. Sometimes, too, it happens that the
claim is troubled by water, and then one man may be constantly employed
in bailing.

It is of great importance in mining with the cradle, to have the cradle
placed within four or five feet of the hole from which the pay-dirt is
obtained, and to have a good supply of water at the head of the cradle,
and then to have a good descent below the cradle, so that the tailings
may all be carried away by the water, so as not to accumulate. The
rocker washes about one-half the amount of dirt that can be washed by
an equal number of men with the tom, one-fourth of what can be washed
with the sluice, and one-hundredth of the amount that can be washed
with the hydraulic process; but it is peculiarly fitted for some kinds
of diggings. Many little gullies, containing coarse gold in their beds,
cannot obtain water for washing except during rains, and then only for
a few days at a time. In these gullies the cradle can be used to the
best advantage, for it can easily be transported, and it is very good
for saving coarse gold. While dirt that would pay from ten to
twenty-five cents, was abundant at the surface of the earth in the
Californian mines, the cradle was extensively used, but now it has been
abandoned by the whites, and is left to the Chinamen, who think
themselves doing well if they make seventy-five cents or one dollar per
day.

The great difficulty in mining with the cradle is, that the sand will
"pack," or make a hard mass on a level with the top of the riffle-bars,
and the gold then is lost. So long as the cradle is in motion the dirt
does not pack, but when the rocking ceases, the mass hardens in a few
minutes. If the miner leaves his cradle standing for fifteen minutes,
he stirs up the dirt with his spoon before commencing again to wash.
One device to prevent packing is to put a little block under each end
of the rockers, so that at the end of every motion the cradle receives
a shock. Quicksilver is sometimes used in cradles, but not usually.

_Pan._--The pan is used in all branches of gold mining, either as an
instrument for washing, or as a receptacle for gold, amalgam, or rich
dirt. It is made of stiff tin or sheet-iron, with a flat bottom about a
foot across, and with sides six inches high, rising at an angle of
forty-five degrees. A little variation in the size or shape of the pan
will not injure its value for washing. Sheet-iron is preferable to tin,
because it is usually stronger and does not amalgamate with mercury.
The pan is the simplest of all instruments used for washing auriferous
dirt. Some dirt, not enough to fill it full, is put in, and the pan is
then put under water. The water ought to be not more than a foot deep,
so that the pan may rest on the bottom, while the miner inserts his
fingers in and under the dirt and lifts it up a little, so that the
whole mass is wet. If the water be deep, the pan may be held in one
hand while the other is used to stir up the dirt, but it is more
convenient to take both. The dirt having been filled with water, the
miner catches the pan at the sides, raises that part toward his body,
and lowers the outer edge a little, and commences to shake the pan from
side to side, holding it so that all the dirt is under water, and so
that a little of the dirt can escape over the outer edge. The earthy
part of the dirt is rapidly dissolved by the water, assisted by the
shaking of the pan and the rolling of the gravel from side to side, and
forms a mud which runs out while clean water runs in. The light sand
flows out with the thin mud, while the lumps of tough clay and the
large stones remain. The stones collect on the top of the clay, and
they are scraped together with the fingers and thrown out. This process
continues, the pan being gradually raised in the water, and its outer
edge depressed, until all the earthy matter has been dissolved, and
that as well as the stones swept away by the water, while the gold
remains at the bottom. Panning is not difficult, but it requires
practice to learn the degree of shaking, which dissolves the dirt and
throws out the stones most rapidly without losing the gold. If the
shaking be too mild and slow, the process consumes too much time;
whereas if it be too rapid and violent, the gold is carried off with
the stones. Sometimes the pan is shaken so that the dirt receives a
rotary motion. This is the most rapid method of washing dirt, but also
the most dangerous. The pan must always be used in cleaning up the dirt
which collects in the cradle, in prospecting, and frequently in washing
small quantities of dirt collected in other kinds of placer mining.
Amalgam can be separated from dirt by washing, almost as well as gold.
In panning out, it frequently happens that considerable amounts of
black sand containing fine particles of gold are obtained, and this
sand is so heavy that it cannot be separated from the gold by washing,
while it is easily separated by that process from gravel, stones and
common dirt. The black sand is dried, and a small quantity of it is
placed in a "blower," a shallow tin dish open at one end. The miner
then holding the pan with the open end from him, blows out the sand,
leaving the particles of gold. He must blow gently, just strong enough
to blow out the sand, and no stronger. From time to time he must shake
the blower so as to change the position of the particles, and bring all
the sand in the range of his breath. The gold cannot be cleaned
perfectly in this manner, but the sand contains iron, and the little of
it remaining is easily removed by a magnet. The blower should be very
smooth, and made of either tin, brass or copper.

_Dry Washing._--Dry washing is a method of winnowing gold from dirt. In
many parts of the mining districts of California, water cannot be
obtained during the summer for mining purposes. The miner therefore
manages to wash his dirt without water. He takes only rich dirt, and
putting it on a raw hide, he pulverizes all the lumps and picks out the
large stones. He then with a large flat basin throws the dirt up into
the air, catches it as it comes down, throws it up again, and repeats
this operation until nothing but the gold remains. Of course a pleasant
breeze, that will carry away the dust, is a great assistance to the
operation. Sometimes two men have a hide or a blanket, with which they
throw up the dirt. The process is very similar to the ancient method of
separating grain from chaff. The miner who devotes himself to dry
washing must be very particular to take only rich dirt, so he scrapes
the bed-rock carefully. He never digs very deep--not more than twenty
feet; and when he goes beyond seven or eight feet he "coyotes," or
burrows after the pay-dirt. He may coyote into the side of a hill, or
sink a shaft and coyote in all directions from it. This style of mining
is named from the resemblance of the holes to the burrows of the
coyote, or Californian wolf. Coyoting is not confined to the dry
washing, but is used also by miners washing with the pan and cradle.
One of the Congressmen elected some years ago to represent California
at Washington, was a miner at the time of his nomination, and was so
fond of coyoting, that he was generally known as "Coyote Joe."

_Dry Digging._--Dry digging is that mining where the miner, after using
the shovel to strip off the barren dirt, scrapes the pay-dirt over with
a knife, picking out the particles of gold as he comes to them, and
throwing away the earthy matter. This is a slow process, but in rich
placers may be profitable. The miner is, of course, particular to
examine all the crevices in the bed-rock; and if the material be slate,
he digs up part of it, to see whether the gold has not found its way
into cracks scarcely perceptible on the surface. "Dry digging," as a
mode of mining, must not be confounded with "dry diggings," a kind of
mining ground which has been described near the beginning of this
chapter.

Knife-mining differs a little from dry digging. In the latter, a shovel
is used to strip off the barren dirt; whereas the knife-mining is
practised in those places where the gold is deposited in crevices in
rocks along the banks of streams, without any covering of barren dirt,
so that the knife alone is used in scraping out the dirt; and afterward
the dirt, being placed in a pan, may be washed in water, which is never
used in dry digging.

_Puddling-Box._--The puddling-box is a rough wooden box, about a foot
deep and six feet square, and is used for dissolving very tough clay.
The clay is thrown into the box, with water, and a miner stirs the
stuff with a hoe until the clay is all thoroughly dissolved, when he
takes a plug from an auger-hole about four inches from the bottom, and
lets the thin solution of the clay run off, while the heavier material,
including the gold, remains at the bottom. He then puts in the plug
again, fills up the box with water, throws in more clay, and repeats
the process again and again until night, when he cleans up with a
cradle or pan. The puddling-box is used only in small mining
operations, and never with the sluice, or in hydraulic claims.

_Quicksilver-Machine._--The quicksilver-machine, or Burke rocker, is a
cradle about seven feet long, two feet wide, and two feet high. In the
bottom are a number of compartments, all containing quicksilver. One
man rocks the machine without cessation. A constant stream of water
pours into the machine at its head. The riddle extends the whole length
of the machine; and the stones, after being washed clean, fall off the
riddle at the lower end. One man is employed constantly working with a
shovel to keep the dirt on the riddle under the stream of water, and in
throwing off the big stones. If the pay-dirt is very convenient, two
men can shovel enough to keep the machine in operation. The Burke
rocker was extensively used in California eight and ten years ago, but
now it is a great rarity.

_Tunnel-Mining._--A tunnel, in California mining, is an adit or drift
entering a hill-side, or running out from a shaft. Mining-tunnels are
usually nearly horizontal--those entering hill-sides having a slight
ascent, for the double purpose of draining the mine, and to facilitate
the removal of the pay-dirt. In a few hills the tunnels run downward at
an angle of twenty degrees or more, to avoid veins or ledges of rock,
which would have to be blasted through if the tunnel were cut
horizontally; but this can only be done with safety in hills which are
drained by older horizontal tunnels.

The mining-tunnel does not run through a hill, but only into it. The
length of tunnels varies greatly; the longest are about a mile. The
usual height is seven feet, the width five feet. Ordinarily the top
must be supported by timbers, to prevent it from falling in, and not
unfrequently the sides must also be protected by boards. The cost of
cutting a tunnel varies from two to forty dollars a longitudinal foot,
according to the nature of the ground, the cost of getting timbers, &c.
Tunnels are usually made by companies of eight or ten men, of whom
one-half may be merchants, lawyers, physicians or office-holders, and
the remainder laboring miners. The latter class do the work; the former
furnish provisions and tools, and a certain amount of cash weekly until
the pay-dirt is reached. Two or three men work at a time cutting a
tunnel; one or two to dig the earth, and one or two to haul it out. The
dirt of the first fifty yards is hauled out in a wheelbarrow; beyond
that distance a little tram-way or railroad is laid down, and the dirt
is hauled out in cars, pushed by the miners. It is not customary to use
horses. It is common to have two relays of laborers--one set working
from noon to midnight, the other from midnight to noon. Work in a
tunnel is as pleasant at night as in the daytime. When a company is
rich, or has many laborers, it may have three relays, each to work
eight hours in the twenty-four.

It is not uncommon for two companies, owning adjacent claims in a hill,
to unite and cut a tunnel on joint account along the dividing line.
They go in until they reach the pay-dirt, and then a surveyor is
employed to run the line between their claims, and the tunnel is
continued through the pay-dirt. The dirt from the tunnel is washed for
the joint account of the two companies. After the dividing line has
been established, each company keeps on its own side, and each has its
time to use the tram-way. They may also have a joint-stock sluice at
the mouth of the tunnel--one company having the privilege of using the
sluice one week, and the other the next. All the dirt brought out in a
week can readily be washed in a day. The work of taking out the
pay-dirt after the main tunnel has been cut, is called "drifting;" and
the holes made by the men engaged in it are termed "drifts." The drifts
are usually not so high as the tunnels. The large stones and barren
dirt obtained in the drifts are piled up here and there to sustain the
earth overhead. Sometimes wooden posts are likewise necessary.

_Shafts._--Shafts are used in prospecting, and also in mining, where
the claims are deep and cannot be reached by either the hydraulic
process or the tunnel. The prospecting shaft is sometimes sunk into
hills supposed to be auriferous, where the shaft is far less expensive
than the tunnel. After the shaft demonstrates that the dirt is rich,
and precisely the altitude at which it lies, a tunnel is cut to strike
it. The shaft may be the cheaper for prospecting, but the tunnel is
usually the cheaper if any large amount of dirt is to be taken out.

The shaft is dug by one man in the hole, and one or two are employed at
a windlass in hauling up the dirt. Mining-shafts in placer diggings are
rarely over one hundred feet deep; but one was dug in Trinity county to
the depth of six hundred feet, for the purpose of prospecting, but it
found neither pay-dirt nor the bed-rock.

_River-Mining._--River-mining is mining for gold in the beds of rivers,
below low-water mark. The only practicable method of doing this is by
damming the stream, and taking the water out of its bed, in a ditch or
flume. It has been proposed by persons who never saw the mines, to get
the gold by dredging, or with a diving-bell; but such schemes are
absurd in the eyes of miners. The rivers in which the gold is found are
mountain-torrents, in which a canoe can scarcely float in summer, much
less a dredging machine; and any large scoop working under water would
miss the crevices and corners in the rocks, where most of the gold is
found. As the water is very seldom more than a couple of feet deep, a
diving-bell would be of little service. The flume, the ditch, and the
wing-dam, are the chief tasks of the river-miner. The ditch is rarely
used, because the banks of the mining-streams are usually so steep,
high, rocky and crooked, that a flume is cheaper. The wing-dam is not
often used, because the river-beds are in most places too narrow. The
flume is almost universally employed.

The work of river-mining can be done only during the summer and fall,
while the water is low, and while the miner can have confidence that it
will not rise. It may be as low in January as in August, but the winter
is the season of rains; and when the flood comes, it sweeps dams,
flumes and every thing before it. If the dam and flume be commenced too
early in the season, they may be carried off before they are finished;
and it frequently happens that they are destroyed in the fall just when
the miners are commencing to reap the reward of their summer's labor.

River-mining has many disadvantages, as compared with other branches of
mining. The miner cannot work at it more than half the year; he cannot
prospect the dirt which is hidden under water; he must erect expensive
dams and flumes, which can be used for only a few months; and then he
is exposed to floods which may come and destroy all his work before he
has commenced to wash. These disadvantages, and the exhaustion of most
of the river-diggings in the state, have almost put an end to
river-mining in California. In a few cases, extensive fluming
enterprises have proved profitable; but, as a general rule,
river-mining in this state has cost more than it has produced. A river
is seldom flumed for less than three hundred yards, and sometimes for a
mile; and the lumber and labor required to make so long a flume, and
one large enough to hold all the water of a river, are very expensive.
The dam will always leak, and water will run into the bed from the
adjacent hills and mountains, and this water must be lifted out by
pumps driven by wheels placed in the flume. The river-beds are full of
large rocks, weighing from one to ten tons, and these must be moved by
machinery, to allow the dirt to be taken out.

River-mining is now never undertaken by an individual, but always by
large associations, generally called "fluming companies," sometimes
composed of miners exclusively, sometimes of miners and all the
principal business-men living near the place where the work is to be
done. The lawyers, doctors and office-holders, pay their assessments in
cash; the merchants furnish provisions, the lumbermen supply lumber,
and the miners make the dam, and help the carpenters build the flume.

_Beach-Mining._--Beach-mining is the business of washing the sands of
the ocean-beach. Between Point Mendocino, in California, and the mouth
of the Umpqua River, in Oregon, the beach-sand contains gold, and in
some places it is very rich. The beach is narrow, and lies at the foot
of a bluff bank of auriferous sand. In times of storm, the waves wash
against this bank, undermine it, sweep away the pieces which tumble
down, leaving the gold on the beach. The gold is in very fine
particles, and it moves with the heavier sand, which alters its
position frequently under the influence of the waves and surf. One day,
the beach will have six feet depth of sand; the next, there will be
nothing save bare rocks. The sand differs greatly in richness at
various times: one day, it will be full of golden specks; a few days
later, at the same place it will be barren. The sand in the mean time
has been moved by the waves, and replaced by other sand.

It is a very difficult matter to know where the sand is rich and where
it is not. The companies employed in mining on the beach number about
ten men; and there is a foreman who rides out early every morning,
following the beach about two miles to the northward and two miles to
the southward of the camp, for the purpose of finding where the sand is
the best. So changeable is the sand, that a new examination is made
every day; and only three or four men are supposed to be good judges of
the quality of sand, from its appearance.

When the foreman has selected a place, he orders all the men to it, and
they go with twenty pack-mules, which carry the sand in _alforjas_, or
raw hide sacks, to the place of washing, which is up on the bluff,
probably a mile or more distant from the spot where the sand is
obtained. It happens occasionally that the foreman rides long distances
on the beach, and sometimes he will order the sand to be obtained ten
miles from the washing-place. The sand must, of course, be very rich,
to pay for such transportation, but the beach-sand at times in the
sunlight is said to be actually dazzling yellow with gold. The purpose
of going upon the bluff to wash it, is to get fresh water for washing;
for the sea-water is not so good, nor can it be obtained conveniently.
The richest dirt is that the farthest down on the beach, so still
weather and low tide are the best times for getting it. When a rich
place is discovered low down on the beach, great exertions are made to
get as much of the sand as possible before the tide rises. When high
tide and storm come together, little can be done. The sand, having been
separated from all clay and soluble matter by the action of the sea, is
very easily washed, and all collected in a month can be washed in two
days in a sluice.

_Mining-Ditches._--The placer-mines of California would yield very
little gold, were it not for the numerous ditches which supply them
with water for washing. The auriferous districts are very dry in
summer, and in some places there is not a spring nor a brook within
many miles. The artificial ditch supplies the want. The ditches are
made by large companies, which sell the water by the "inch." An inch of
water is as much as will run out of an orifice an inch square, with the
water standing six or seven inches deep in the flume over the orifice.
The depth of water over the orifice is called the "head." The orifice
is usually two inches high, and as long as necessary to give the amount
of water desired. Nobody wants less than ten or twelve inches for
mining: a "sluice-head" is about eighteen inches; a "hydraulic-head" is
from forty to two hundred inches. The water, however, is not measured
accurately. Of course the amount which runs through the orifice will
depend to a considerable extent upon the "head," which is usually
greater in the morning than at night. At sunrise there may be fifteen
inches head, and at sunset only three. The water collects during the
night, and is exhausted during the day. The price of water is in no
place less than ten cents an inch per day; in some places it is forty
cents; the average is about twenty cents.

Many of these ditches are extensive enterprises, and have cost hundreds
of thousands of dollars. When they cross ravines and valleys, large
flumes--wonders of carpentry--must be built. Some of these are two
hundred feet high and a mile long, and so large that a horse and waggon
can be driven through them. In all, save length and durability, they
are as wonderful as the great Roman aqueducts, whose tall ruins still
stand in the Campagna, near the Eternal City. In some cases iron tubes
have been used, and although they are very expensive, yet they may pay
for themselves, by preventing evaporation, leaking and soaking, which
take away much of the water from flumes and ditches.

_Prospecting._--"Prospecting" is the search for gold. The instruments
used by the prospector for placer-mines are usually the pan, pick and
shovel. He should be familiar with the general laws of the distribution
of gold, and then try the dirt in the most favorable places. If there
is any gold in a district, he can scarcely fail to find specks of it by
washing dirt from the bed-rock in the ravines, and in bars. The
existence of gold in a district having been established, close
observation will suggest to the prospector where he may reasonably
expect to find the best diggings. It is usually found that placer-gold
is collected in those places where, if he had been familiar with the
ancient topography of the country, he should have had reason to suppose
that it would be.

_Quartz Mining._--Quartz mining differs much from placer mining. For
the former, more capital, more experience, more complicated machinery
and richer material are required than for the latter. The placer miner
throws the dirt into the water, which then does the work; whereas the
pulverizing of rock is a nice operation, requiring constant attention.
Quartz requires a mill and water-power; placer dirt is washed in a
simple sluice. Dirt containing ten cents in the cubic yard may pay the
hydraulic miner, but the quartz miner must have a hundred times as much
in a cubic yard of vein stone, or he cannot work. The placer gold, when
freed from the baser material surrounding it, is much of it in coarse
particles, which are easily caught by their specific gravity; the
quartz gold must be reduced to a fine powder before it be set free from
its gangue, and with the fineness of the particles increases the
difficulty of catching them.

Auriferous quartz lodes are often found by accident. Not unfrequently
it happens that a rich streak of pay-dirt in a placer claim is followed
up to the quartz vein from which it came. While miners are out walking
or hunting, they occasionally will come upon lodes in which the gold is
seen sparkling. Some good leads have been found by men employed in
making roads and cutting ditches. The quartz might be covered with
soil, but the pick and shovel revealed its position and wealth. In
Tuolumne county in 1858, a hunter shot a grizzly bear on the side of a
steep _canon_, and the animal tumbling down, was caught by a projecting
point of rock. The hunter followed his game, and while skinning the
animal, discovered that the point of rock was auriferous quartz. In
Mariposa county, in 1855, a robber attacked a miner, and the latter saw
the rock behind his assailant sparkle in the sunlight, at a spot where
a bullet struck a wall of rock. He killed the robber, and found that
the rock was gold-bearing quartz. In Nevada county, several years ago,
a couple of unfortunate miners who had prepared to leave California,
and were out on a drunken frolic, started a large boulder down a steep
hill. On its way down, it struck a brown rock and broke a portion of it
off--exposing a vein of white quartz which proved to be auriferous,
induced the disappointed miners to remain some months longer in the
state, and paid them well for remaining. Science and experience do not
appear to give much assistance in prospecting for quartz lodes.
Chemists, geologists, mineralogists and old miners, have not done
better than ignorant men and new-comers. Most of the best veins have
been discovered by poor and ignorant men. Not one has been found by a
man of high education as a miner or geologist. No doubt geological
knowledge is valuable to a miner, and it should assist him in
prospecting; but it has never yet enabled any body to find a valuable
claim.

_Distribution of Gold in Quartz._--The rich quartz-veins of California
extend from Kern River to the Siskiyou, are found on hills, in _canons_
and in vales. They are at least two thousand feet above the level of
the sea, and not more than ten thousand feet above it. Their course is
generally from north-north-west to south-south-east, and they dip
steeply to the eastward, sometimes being nearly perpendicular. They
differ in thickness from a line to sixty feet. Quartz veins are very
numerous in most of the mining districts, so the task is not to find
the veins, but rather to find those which are gold-bearing. It is
supposed that nearly all large veins come to the surface of the
bed-rock or "country;" but many of them are covered with soil and thus
are hidden. Hidden veins are called "blind;" those plainly visible on
the surface are called "croppings veins," because their position is
shown by the out-croppings. Experience has not ascertained whether
large or small veins are more likely to contain gold. It is found in
both. The porous quartz, or that containing many cavities, is more
frequently found auriferous and richly auriferous, than the very
compact quartz. The best gold-bearing veins are usually yellowish or
brownish in tinge, near the surface at least; but very rich specimens
are found in white and bluish-white rock. Most quartz veins in
California contain a little gold; the metal seems to have been
distributed most lavishly, but unfortunately in nine-tenths of the
veins, the proportion of metal is too small to pay. Most of the large
veins are supposed to run for miles upon miles, though they can rarely
be traced clearly on the surface for more than a furlong. The
auriferous veins vary much in richness. No vein is wrought for more
than a few hundred feet. Beyond that, it is either too poor to pay, or
the vein is hidden. Some persons have supposed that there is one great
gold-bearing quartz vein running along the side of the Sierra Nevada,
from Mariposa to Plumas county, and that many of the richest claims are
really in this one vein; but this a supposition which cannot be proved
now. Sometimes a vein seems to spread out and divide into a number of
smaller veins, all of which afterward unite again. These points of
junction, and the narrower places in the vein, are usually richer than
other parts of it. When two veins cross each other, one may be
auriferous on one side of the intersection and not on the other; but in
this case the other vein will be auriferous on both sides. It is as
though they were streams, one rich, the other barren, and that after
meeting, the wealth of the one was divided between them. It is a
general rule that metalliferous veins running parallel with the strata
of the bed-rock or country are not extensive. In fact they are rather
deposits than veins, and though often extremely rich are soon
exhausted, while the lodes which run across the stratification, run far
and deep, and have a regular and straight course and dip. Lodes lying
between two different kinds of rock, are usually richer than those
which have the same kind of rock on both sides. Thus it is said that
the richest veins of auriferous quartz in California, have been
discovered at the intersection of trap and serpentine, and the richest
places in veins are where they cross from one kind of bed-rock into
another. The richest part of a lode of auriferous quartz is almost
invariably on the lower side of the vein, near the foot-wall. All these
are facts to be remembered by the prospector as a guide, and an
assistance to him in his search for a rich gold-bearing vein. If the
lode is covered with earthy matter, he may sometimes trace its course
by the difference in the color of the dirt and stones over it from that
elsewhere. When the prospector finds dirt and stones on a vein,
evidently disintegrated portions of it, he should wash some of the dirt
in a pan, and if he finds no gold, there is a strong presumption that
the vein is barren.

_Prospecting Quartz Rock._--After finding a gold-bearing vein, the
question arises whether it will pay. Great sums are lost in gold-mining
countries by injudicious investments in mills and machinery to work the
auriferous rock, and persons going into the business should be
particularly careful not to commit this great error. The business of
quartz mining has great profits, but also great pecuniary dangers
connected with it. It is rarely that all the rock of a vein will pay
for working. In some lodes, the vein-stone will average one hundred
dollars to the ton, for all the stone found in a certain part of the
lode, but beyond that the rock may be poor or worthless. Picked
specimens may be worth several thousand dollars to the ton, but perhaps
not more than a ton of such specimens has been obtained in the best
lode ever opened in the state. The most profitable lodes are those
which have a large supply of rock, easily to be obtained, and all of it
yielding something above the cost of working. The common method of
ascertaining whether rock will pay, is to pulverize a little of it and
wash it in a horn spoon. In taking out the quartz rock in large lodes,
it is important to take out only that which will pay, and to determine
this, the superintendent of the quarry-men must occasionally test the
vein-stone. He takes several little pieces of it, average specimens,
places them on a hard, smooth, flat stone, about a foot square, on
which he crushes them with a stone muller four inches square, and then
by rubbing with the muller he reduces them to a fine powder. He has a
horn spoon, made of a large ox-horn, with a bowl about three inches
wide, and eight inches long, being merely one-half of the horn in its
natural shape. With this spoon he washes out the powder in water, and
if he does not find a speck of gold or a "color," as it is called, in a
pound of the rock, he infers that it will not pay. The three principal
quartz mines in the state are those of Fremont in Mariposa county, of
the Allison company in Nevada county, and of the Sierra Butte company
in Sierra county. The first has produced $75,000 in a month, the second
$60,000, and the third $20,000, but the average is probably thirty per
cent. less, and the expenses about thirty per cent. of the total
product. The average yield of the Fremont rock is fourteen dollars to
the ton, of the Sierra Butte rock eighteen dollars, and that of the
Allison company, according to report, has for more than a year at a
time been one hundred dollars per ton. The cost of working quartz rock,
including quarrying, crushing and amalgamating, is in the best mills
from five to ten dollars per ton. The width of the vein, the softness
of the rock, the amount of work done, and the skill and industry of the
workmen, all are items of great importance in estimating the cost of
quartz-mining. It is a business which the owner of the mill ought to
understand. The cost of quarrying common quartz rock is about two
dollars per ton, that is, for mill-owners that understand the business
and superintend the labor themselves. When given out by the job, it
usually cost more. When quartz is crushed in a custom mill, that is, a
mill built to crush for all applicants, the cost is rarely less than
five dollars per ton, and in Washoe, the price was at one time thirty
dollars per ton; but in the large mills, where many tons are crushed
every day, is about two dollars per ton.

_The Divining Rod._--In prospecting for auriferous quartz, use is
sometimes made of the divining rod, a practice not without credit with
some good miners. The rod is a fork of a green hazel-bush, shaped like
a V, with the arms about a foot long. The prospector holds the end of
an arm in each hand, with the point of the V directed forward
horizontally, and as he walks along, the point turns down whenever he
comes over a metalliferous vein, metallic body or water. It is supposed
that very few persons can use the divining rod effectually; for most
men it refuses to turn. It is used in nearly every civilized country,
especially by miners, and is generally considered superstitious,
because it is employed by ignorant people, and because there has been
no generally accepted scientific explanation of the manner in which a
stick could be influenced by a metal hidden under ground. A scientific
explanation of the principle of the divining rod has been offered to
the world, by Baron Reichenbach, (see page sixty of his _Odic-Magnetic
Letters_, translated by John S. Hittel).

_Quarrying Quartz._--The quarrying of quartz rock differs little from
the quarrying of other metalliferous vein-stones. The lode descends
steeply, and the excavation must follow its course. Sometimes the
quartz is so soft that it may easily be loosened with the pick. The
harder rock is blasted. Soft quartz is that which is penetrated by
numerous cavities, though the lumps between the cavities may be very
hard. Some quartz on exposure to the air crumbles into sand, though
hard when first taken from the vein. In narrow lodes, some of the
wall-rock must be cut away to get room for the workmen. In wide lodes,
that part of the vein-stone which does not pay is left. Sometimes the
gold from the lode penetrates a little way into the foot-wall, and in
that case the quarrying must extend beyond the vein stone. The quartz
loosened in the vein, must either be hoisted perpendicularly in a
bucket with a windlass, or be hauled out through a tunnel. The common
method is to hoist the rock with a windlass. Most of the veins are in
such places that shafts are more easily dug than tunnels. After the
excavation has extended twenty or thirty feet below the surface, it is
usual to dig a perpendicular shaft, so as to strike the vein sixty or
seventy feet below the surface, and from this point the miner or
"drifter" works upward, and as he loosens the rock it falls to the
bottom of the shaft, where it is put in the bucket to be hoisted to the
surface. Our quartz mines are generally in dry hills, so that they are
not troubled much by water; but there are a few shafts where
steam-pumps are constantly at work to carry off the water.

Occasionally the miners find small quantities of auriferous quartz
which are so easily broken up, and the pieces of gold in which are so
coarse, that after the rock has been pounded a little in a mortar, the
metal can easily be picked out with the fingers.

_Arastra._--Quartz is pulverized either in an arastra, or Chilean mill,
or by stamps.

The arastra is the simplest instrument for grinding auriferous quartz.
It is a circular bed of stone, from eight to twenty feet in diameter,
on which the quartz is ground by a large stone dragged round and round
by horse or mule-power. There are two kinds of arastras, the rude or
improved. The rude arastra is made with a pavement of unhewn flat
stones, which are usually laid down in clay. The pavement of the
improved arastra is made of hewn stone, cut very accurately and laid
down in cement. In the centre of the bed of the arastra is an upright
post which turns on a pivot, and running through the post is a
horizontal bar, projecting on each side to the outer edge of the
pavement. On each arm of this bar is attached by a chain a large flat
stone or muller, weighing from three hundred to five hundred pounds. It
is so hung that the forward end is about an inch above the bed, and the
hind end drags on the bed. A mule hitched to one arm will drag two such
mullers. In some arastras there are four mullers and two mules. Outside
of the pavement is a wall of stone a foot high to keep the quartz
within reach of the mullers. About four hundred pounds of quartz,
previously broken into pieces about the size of a pigeon's egg, are
called a "charge" for an arastra ten feet in diameter, and are put in
at a time. The mule is started, and in four or five hours the quartz is
pulverized. Water is now poured in until the powder is thoroughly mixed
with it, and the mass has the consistence of thick cream. Care is taken
that the mixture be not too thin, for the thickness of it is important
to the amalgamation. The paste being all right, some quicksilver (an
ounce and a quarter of it for every ounce of gold in the quartz, and
the amount of gold is guessed at from the appearance of the rock) is
scattered over the arastra. The grinding continues for about two hours
more, during which time it is supposed the quicksilver is divided up
into very fine globules and mixed all through the paste (which is so
stiff that the metal does not sink in it to the bottom), and that all
the particles of gold are caught and amalgamated. The amalgamation
having been completed, some water is let in three or four inches deep
over the paste, and the mule is made to move slowly. The paste is thus
dissolved in the water, and the gold, quicksilver and amalgam have an
opportunity to fall to the bottom. At the end of half an hour, or
sooner, the thin mud of the arastra is allowed to run off, leaving the
precious material at the bottom. Another charge of broken quartz is now
put in and the process is repeated, and so on. The length of a "run,"
or the period from one cleaning up to another, varies much in different
places. In the rude arastra a run is seldom less than a week, and
sometimes three or four. The amalgam having settled down between the
paving stones, the bed must be dug up and all the dirt between them
carefully washed. In the improved arastra the paving fits so closely
together, that the quicksilver and amalgam do not get down between
them, but remain on the surface, and can readily be brushed up into a
little pan, and therefore cleaning up is much less troublesome and is
more frequently repeated than in the rude arastras; besides there is a
greater need of frequent cleaning up in the improved arastras, because
the amount of work done within a given time is usually greater.

The arastra is a slow instrument, but in some important respects it is
superior to any other method of working auriferous quartz. It grinds
the quartz well, is unsurpassable as an amalgamator, is very cheap and
simple, requires no chemical knowledge or peculiar mechanical skill in
the work, requires but little power, and very little water--all of them
important considerations. In many places, the scarcity of water alone
is enough to enable the arastra to pay a larger profit than any other
method. Again, if a miner finds a rich spot in a lode, he may be
doubtful as to the amount of paying rock which he can obtain. Such
cases very frequently happen in California, and the arastra is just the
thing for the case; for then if the amount of paying rock is small,
nothing is lost, whereas the erection of a stamping-mill would cost
much time and money, and before it could get into smooth operation the
rich rock would be exhausted, and the mill perhaps become worthless. No
other simple process of amalgamation is equal to that of the arastra;
and it has on various occasions happened in California, that Mexicans
making from fifty to sixty dollars per ton from quartz, have sold out
to Americans who have erected large mills at great expense, with patent
amalgamators, and have not been able to get more than ten or fifteen
dollars from a ton. The arastra is sometimes used for amalgamating
tailings which have passed through stamping-mills.

_Chilean Mill._--The Chilean mill has a circular bed like the arastra,
but much smaller, and the quartz is crushed by two large stone wheels
which roll round on their edges. In the centre of the bed is an upright
post, the top of which serves as a pivot for the axle on which both of
the stones revolve. A mule is usually hitched to the end of one of the
axles. The methods of managing the rock and amalgamating with the
Chilean mill, are very similar to those of the arastra. The Chilean
mill, however, is rarely used in California; the arastra being
considered far preferable.

_Stamps._--Nine-tenths of the quartz crushed in California is
pulverized by stamps, of which there are two kinds, the square and
rotary. The square stamp has a perpendicular wooden shaft, six or eight
feet long, and six or eight inches square, with an iron shoe, weighing
from a hundred to a thousand pounds. The wooden shaft has a mortice in
front near the top, and a cam on a revolving horizontal shaft enters
this mortice at every revolution. When the cam slips out of the
mortice, the stamp falls with all its weight upon the quartz in the
"battery" or "stamping-box." The rotary stamp has a shaft of wrought
iron about two inches in diameter, and just before falling this shaft
receives a whirling motion, which is continued by the shoe as it
strikes the quartz. The rotary stamp is considered superior to the
square, its advantage being that it crushes more rock with the same
power, that it crushes more within the same space, and that it wears
away less of the shoe in proportion to the amount of rock crushed.
There are usually half a dozen square stamps or more, standing side by
side in a square-stamp mill, and these do not all fall at the same
moment, but successively, running from the head to the foot of the
"battery." The quartz is put in at the head of the battery, and is
gradually driven to the foot. The rotary stamps sometimes stand side by
side, and sometimes in a circle. The battery of both rotary and square
stamps is surrounded by wire gauze, or a perforated iron plate,
allowing the finely pulverized quartz to escape, and retaining the
coarser particles. Quartz is crushed wet and dry. In wet crushing a
little stream of water runs into the battery on one side and escapes on
the other, carrying all the fine quartz with it.

_Separation._--After pulverization comes the separation of the gold
from the rocky portion of the powder. The means of separation are
mechanical or chemical. The chemical process is amalgamation; the
mechanical are those wherein the gold is caught on a rough surface with
the aid of its specific gravity. The chief reliance is upon
amalgamation, and in some large quartz-mills mechanical appliances are
not used at all for catching the particles of gold, but only for
catching amalgam.

The mechanical appliances used in quartz-mills in separating the gold
from the pulverized rock, are the blanket, the sluice, and the raw
hide.

The blanket is a coarse, rough, gray blanket, which is laid down in a
trough sixteen inches wide and six feet long. The pulverized quartz is
carried over this by a stream of water, and the particles of gold are
caught in the wool. The blanket is taken up and washed, at intervals
depending upon the amount of gold deposited. In some mills where a
large amount of rock is crushed, and where the powder is taken over the
blanket before trying any other process of separation, the washing
takes place every half hour. In mills where the pulverized quartz is
exposed to amalgamation first, the blanket may be washed three or four
times a day. The washing is done in a vat, kept for that especial
purpose.

The sluice used in quartz-mills is similar to the placer board-sluice,
but the amount of matter to be washed is less, and there is no dirt to
be dissolved, and there are no larger stones, and therefore the sluice
is not so large, so strong, or so steep in grade, as the placer-sluice,
and the riffle-bars are not so deep. In some quartz-mill sluices there
are transverse riffle-bars. If the quartz has much iron or copper
pyrites, the sluice is used to collect this material and save it for
separation at some future time. The pyrites ordinarily contains, or is
accompanied by much gold, which it protects from amalgamation. This
separation of the pyrites from the pulverized rock is called
"concentrating the tailings," and the material collected is called
"concentrated tailings." In the sluices of some quartz-mills cast iron
riffle-bars are used; cast in sections about fifteen inches square, and
about an inch deep. Much study has been devoted to the subject of
making these riffle-bars in such a manner that the dirt will not pack
in them, but will always remain loose, and keep in constant motion
under the influence of the water running over them; but the object has
never been fully attained. Quicksilver is used in nearly all
quartz-mill sluices.

The raw hide used in separating gold from the pulverized quartz is a
common cow hide, laid down in a trough with the hairy side up, and the
grain of the hair against the course of the water. The gold is then
caught in the hair. Sheep hides have been used in the same manner,
recalling to mind the Golden Fleece. The hides, however, are inferior
to the blankets for this purpose, and are never used in the best mills.

The methods of amalgamating are numerous. Among them are amalgamation
in the battery, amalgamation with the copper plate, amalgamating bowls,
and patent amalgamation of many kinds.

In many mills quicksilver is placed in the battery, two ounces of
quicksilver for one of gold; and about two-thirds of the gold is caught
thus. The copper plate in quartz-mills is made in the same manner as in
placer-sluices, under which head a description of the plate may be
found. Some amalgamating bowls or basins are little Chilean mills and
arastras, made of cast iron. One plan of amalgamation is to use a cast
iron bowl about four feet in diameter and a foot deep. Near the bottom
are horizontal iron arms, which revolve and stir the quicksilver and
pulverized quartz together. Four or five of these bowls sit in a row
but at different levels: the bottom of the first bowl being level with
the top of the second, and so on. The pulverized quartz passes through
them all. Under each bowl a fire is kept up, because heat forms the
action of amalgamation. If there be any pyrites in the quartz, some
common salt is thrown in to assist in releasing the gold from the
embraces of the sulphurates, and preparing it to be seized by the
mercury. Another amalgamating bowl revolves on an axis that stands at
an angle of about seventy-five degrees to the horizon, so that the
material in the bowl is continually moving; and the bottom is divided
by little compartments, which make a constant riffle. In other bowls
the pulverized quartz is forced with water through the mercury. The
methods of amalgamation differ very much, and a book might be filled
with a description and discussion of the processes used at different
quartz-mills in California.

_Sulphurets._--Many auriferous quartz veins contain considerable
quantities of sulphurets or pyrites of iron, copper and lead, and their
presence prevents amalgamation, and thus causes a great loss of gold.
It is said that on some occasions in good mills, not more than twenty
or thirty dollars have been obtained from a ton of vein-stone which had
seven or eight hundred dollars of gold in every ton. The best method of
treating the quartz containing pyrites, is to roast it, and thus drive
off the sulphur, but this process is so expensive that it is seldom
used; and the common practice is to crush and amalgamate the rock, and
save the concentrated tailings for some future time, when there may be
a sale for them, or when it will be cheaper to reduce them. The
pulverized sulphurets are decomposed by exposure to the air, and after
the tailings have been preserved for a time, they may pay better at the
second amalgamation than at the first. A mixture of common salt assists
the decomposition of the pyrites.

_Chief Quartz-Mills._--The most productive quartz-mill in the state is
the Benton mill, on Fremont's Ranch, in Mariposa county. It is also the
largest, having forty-eight stamps. There are four mills on the estate,
with ninety-one stamps in all, and their average yield per month is
sixty thousand dollars. A railroad four miles long, conveys the quartz
from the lode to the mills. The Allison quartz mine in Nevada county,
produces forty thousand dollars per month. The Sierra Buttes
quartz-mill, twelve miles from Downieville, yields about fifteen
thousand dollars per month. These last mills run night and day, and
crush and amalgamate ten thousand tons of rock a year, or twenty-eight
tons per day. Forty men are employed, twenty-five to quarry the rock,
five in the mill to attend to the stamps and amalgamation, one to do
carpentry, one for blacksmithing, and eight for getting out timber,
transporting quartz, and so forth. The cost of quarrying, crushing and
amalgamating a ton of rock, is six dollars. The wages of the men are
from fifty to seventy dollars per month with boarding. The average
wages is sixty dollars. About ten miles eastward of Sonora, in Tuolumne
county, are some rich veins of auriferous quartz, the most prominent of
which are the Soulsby and Blakeslee lodes. The Soulsby mill produced
forty thousand dollars in three weeks, when it commenced work in 1858,
but it has not been so profitable of late.

_Silver Mining._--Silver mining has not yet been established fairly as
a business in California. The silver ores of Washoe were discovered in
1859, and mining has been fairly commenced there, but the mines of
Esmeralda and Coso, within the limits of this state, were not found
until the summer of 1860, and up to the present time no mills have been
established there.

Silver mining differs much from gold mining. Gold is always found as a
metal, never as an ore, and the separation from the accompanying
vein-stone with which it is mixed mechanically, is much more simple and
easy than the reduction of the argentiferous ores in which the silver
is chemically combined with base substances, for which it has a strong
affinity. Chemical knowledge and chemical processes are more necessary
in mining for silver than for gold; and while all auriferous quartz is
of the same kind, and may be treated in the same manner, there are many
different kinds of silver ores, each of which requires a peculiar
treatment. The reduction of silver ore costs on an average, from three
to five times as much as the reduction of auriferous quartz.

The silver ore of Esmeralda and Coso is a sulphuret of silver, nearly
all the veins having the same material, though the amount of it
scattered through the vein-stone differs greatly in different lodes. In
some veins there is much free gold, that is, little specks of metallic
gold which can be separated from the other material in the same manner
that gold is separated from auriferous quartz. The methods of reducing
silver ore are so numerous and complex, and vary so much in different
districts and under different circumstances, that it is impossible to
know now what process will be used in Esmeralda and Coso, the resources
of which places have been so little studied. Besides it is said that
new processes for reducing silver ore have been invented, far superior
to all the old methods; and these processes are kept secret. It is
therefore unnecessary that I should go into a long description of the
various processes practised elsewhere. Silver ore after pulverization
is smelted by mixing with it fifty per cent. of lead in metal or ore,
and ten per cent. of iron, and exposing the whole to a heat sufficient
to melt the silver which runs off. The metal thus obtained is not pure
but contains much lead, which is driven off by heat while the silver is
kept in a molten condition for a period of four or six hours. The cost
of smelting in California at present, is about one hundred and
twenty-five dollars per ton. In most of the other methods of reducing
silver ore, the ore is roasted to drive off the sulphur. In the barrel
amalgamation, which has been used at Washoe, and will probably be used
at Esmeralda also, half a ton of ore, after being pulverized and
roasted, three hundred pounds of water, and one hundred pounds of
wrought iron, in little fragments, are put into a barrel, which
revolves on a perpendicular axis. At the end of two hours the mass has
taken the consistence of thick cream, when five hundred pounds of
quicksilver are put in, and after the barrel has revolved four hours
more, the amalgamation is complete. More water is now poured in; the
barrel revolves very slowly to let the amalgam all settle to the
bottom, the mud runs off through a cock four inches above the bottom,
and the mercury and amalgam are then drawn off through a little hole in
the bottom of the barrel.

_Quicksilver Mining._--The ore from which quicksilver is obtained is a
sulphuret. The sulphur is driven off by heat, and the metal, which
rises in fumes from the ore, is collected by condensation. The miners
are Cornishmen and Mexicans. The ore is in large masses underground,
not in a connected vein of regular thickness; and after one mass is
exhausted, much labor is often vainly spent in search of another. There
are, however, usually little seams of ore running from one large
deposit to another, and it is the business of the mining captains to
observe these veins closely, and trace them up when a "fault" occurs.
There are no scientific rules for finding the ore; and the business of
searching for the large deposits is never intrusted to educated mining
engineers, but always to mining captains, who have themselves been
laborers, and have learned by experience where to seek. The New Almaden
mine produces two hundred and twenty thousand pounds of metal in a
month. The _hacienda_, or reducing establishment of the mining company,
has fourteen brick furnaces, each fifty feet long, twelve feet high,
and twelve feet wide. At one end of each furnace is the fire chamber,
which may be nine cubic feet inside; next to that is the ore chamber of
about the same size; and beyond that is the condensing chamber, in
which there are a number of partitions alternately running up from the
bottom and down from the top, with a space for the fumes to pass, their
course being up and down, and up and down again, and so on, for a
distance of thirty feet to the chimney, which is forty feet high. In
the bottom of the condensing chamber is water. The walls between the
fire chamber and the ore chamber, and between the latter and the
condensing chamber, are built with open spaces, so that the heat, smoke
and fumes can pass through. The ore is placed in the ore chamber in
such a manner as to leave many open spaces. The heat drives off the
sulphur and mercury of the ore in fumes, which in passing through the
condensing chambers, deposit the mercury, and the smoke and sulphur
escape through the chimney. In the Enriqueta and Guadalupe mines the
quicksilver is condensed in a close iron retort, and the sulphur is
absorbed by quicklime.

Copper ore is dug from several mines in California, but it is all
exported to be smelted elsewhere.

_Platinum._--Platinum, iridium and osmium, three white metals of about
the same specific gravity with gold, are found with the latter metal in
the placers in the basin of the Klamath and Trinity Rivers. Their
particles are usually fine scales, very rarely reaching a quarter of an
ounce in weight, and the largest piece of either ever found was less
than an ounce and a half. They cannot be separated from the gold by
washing, but they do not unite with quicksilver, and therefore they are
separated from the more precious metal by amalgamation. They have no
regular market in the state; miners never make them the chief object of
search, and they have not been studied, so it is not known to what
extent they might be obtained.

_Del Norte and Klamath._--Del Norte county in the north-western corner
of the state, is about forty miles long from east to west by thirty
from north to south. The mining population in it is small. Most of the
mining is done along the banks of the Klamath River, which runs about
twenty miles through the south-eastern portion of the county. There are
some miners on the head-waters of Althouse Creek, which runs northward
into Oregon. The county assessor, in his report for 1860, does not
mention the existence of any quartz-mill or mining-ditch in the county.
The mining districts are very mountainous and difficult of access. They
obtain most of their supplies from Crescent City. The mining is chiefly
in shallow placers, in deep and narrow ravines, and on bars of the
Klamath River.

Klamath county lies immediately south of Del Norte, and is about the
same size. It is almost exclusively a mining county, and has a
population of about eighteen hundred. The diggings are placers in the
bars and banks of the Klamath River and its tributaries, the Trinity
and Salmon Rivers, and many small creeks. The principal mining places
are Orleans Bar, Gullion's Bar, Negro Flat, Cecilville, Weitspeck and
Red Cap. The whole county is very rugged and mountainous, and much of
it is covered with heavy timber. The diggings are so difficult of
access, and are so protected by mountains against ditches, that they
will last for many years. There is probably no part of the state where
the single miner, without capital, has a better chance to dig gold with
a profit. Nearly the whole beach of the county is auriferous.

_Siskiyou._--Siskiyou county lies east of Del Norte and Klamath, is
forty miles wide from north to south, one hundred miles long from east
to west, and reaches to the eastern boundary of the state. It has a
population of 7,629, the large majority of whom are engaged in mining.
The mining district is all in the western end of the county, along the
banks of the Klamath River and its tributaries, the Scott and Shasta
Rivers. The Klamath runs through a deep _canon_; the Scott and Shasta
Rivers, have pleasant open valleys, but the diggings along their banks
are chiefly among the _canons_ near the Klamath. Hydraulic and tunnel
claims are rare. There are six quartz-mills in the county, and fifteen
mining ditches, of which last the principal is the Yreka canal, forty
miles long, bringing water from the head of Shasta River to the town of
Yreka. In 1859, there were four quartz-mills in the county, one of
which was at Mugginsville, one in Scott's valley and two in Quartz
valley. I have no information about the situation of the two built
since that time. The principal mining towns are Yreka, Scott's Bar,
Hawkinsville, Johnson's Bar, Deadwood and Cottonwood.

_Trinity and Shasta._--South of the western part of Siskiyou and the
eastern part of Klamath, lies Trinity county, ninety miles long from
north to south, and about twenty miles wide on an average. The northern
part of the county is the basin of the Trinity River, and is
auriferous. From the county assessor's report for 1860, it is to be
inferred that there is not a quartz-mill or a mining-ditch in the
state. The county is very mountainous, and most of the mining is done
in rugged _canons_ along the Trinity River. The chief mining towns are
Weaverville, Cox's Bar, Big Bar, Arkansas Flat, Mooney's Flat and
Trinity Centre.

South of Siskiyou and east of Trinity lies Shasta county, which is on
an average forty miles wide from north to south and one hundred miles
long, reaching to the eastern border of the state. There is a rich
auriferous district about twenty miles square, in the vicinity of the
town of Shasta, in the south-western part of the county. The diggings
are mostly in the basins of Clear Creek, Cottonwood Creek, Rock Creek
and Salt Creek, all of which enter into the Sacramento. There are four
quartz-mills in the county, one at French Gulch, one at Middle Creek,
one at Muletown, and one at Old Diggings. The county has twenty-seven
mining ditches, with a joint length of one hundred and forty-one miles,
an average of five miles each. The chief mining towns are Shasta,
Horsetown, French Gulch, Muletown, Briggsville, Whiskey and Middletown.

_Plumas and Sierra._--South of the eastern part of Shasta county lies
Plumas, which is about seventy miles square. About one third of the
county, in the south-western part of it, comprising that portion
drained by the head waters of Feather River, is auriferous. It lies
high above the level of the sea, and the work of mining is interrupted
during a considerable portion of the winter, by cold, snow and ice.
Hydraulic and tunnel claims in deep hills, furnish a large portion of
the gold yield of the county. There are five quartz-mills, one at
Elizabethtown, one at Eureka Lake, and three at Jamison Creek. The
principal mining towns are Quincy, Jamison City, Indian Bar, Nelson's
Point and Poorman's Creek.

South of Plumas is Sierra county, which is fifty miles long from east
to west, and twenty miles wide from north to south. The North Fork of
the Yuba River runs through its centre, and the Middle Fork is its
southern boundary. Though small, it is one of the richest mining
counties of the state, and in proportion to the extent of its mining
ground, is much richer than any other county. All its territory is four
thousand feet above the sea level, at the lowest. Most of the mining is
done in hydraulic and tunnel claims in deep hills. Near the centre of
the county is a mountain called the Downieville Butte, or the Yuba
Butte, eight thousand eight hundred and forty-six feet high, on the
sides of which are found some rich quartz leads. In 1859 there were
eleven quartz-mills in Sierra county, of which seven are at the Butte,
two at Downieville, one at the Mountain House, and one at Sierra City.
The principal mining towns are Downieville, Monte Cristo, Pine Grove,
St. Louis, La Porte, Poker Flat, Eureka City, Forest City, Alleghany
Town, and Cox's Bar. One of the most remarkable features of the placers
of the state, is the blue lead, which was first discovered in Sierra
county, and has been more thoroughly examined there than elsewhere. The
"blue lead" is a stratum of blue clay very rich in gold. It is found
deep under other strata. The general opinion is, that the blue lead
occupies the bed of a large antediluvian river, which ran parallel with
the Sacramento and about sixty miles eastward of it. It has been traced
twenty miles or more, passing near Monte Cristo, Alleghany Town, Forest
City, Chip's Flat and Zion Hill. Mr. C. S. Capp wrote thus to the San
Francisco _Bulletin_:

"This is not one of the many petty leads, an inch or two in breadth and
thickness, which, after being traced a few hundred feet, end as
suddenly and mysteriously as they commence; but it is evidently the bed
of some ancient river. It is often hundreds of feet in width, and
extends for miles and miles, a thousand feet below the summits of high
mountains, and entirely through them. Now it crops out where the deep
channels of some of the rivers and ravines of the present day have cut
it asunder; and then, hidden beneath the rocks and strata above it, it
only emerges again miles and miles away. Wherever its continuity has
been destroyed, the river or gulch which has washed a portion of it
away, was found to be immensely rich for some distance below, and the
materials of which the lead is composed are found with the gold in the
bed of the stream. It is evidently the bed of some ancient stream,
because it is walled in by steep banks of hard bed-rock, precisely like
the banks of rivers and ravines in which water now runs, and because it
is composed of clay which is evidently a sedimentary deposit, and of
pebbles of black and white quartz, which could only be rounded and
polished as they are by the long continued action of swiftly running
water. The bed-rock in the bottom of this lead is worn into long smooth
channels, and also has its roughness and crevices like other river
beds. The lighter and poorer qualities of gold are found nearest to its
edges, while the heavier and finer portions have found their way to the
deeper places near the centre. Trees and pieces of wood, more or less
petrified and changed in their nature, which once floated in its
waters, are also every where encountered throughout this stratum.

"The clay and fine gravel in which these pebbles and boulders are found
to be tightly packed, is of a light-blue color, which gives the name to
the lead. Much of this clay is remarkably fine and free from coarse
particles, and is smooth and unctuous to the touch. It is said to be
strongly impregnated with arsenic, as was shown by chemical analysis,
and contains large quantities of iron and sulphur in solution, for
pyrites and sulphurets of iron are deposited in shining metallic
crystals in every vacant crevice. Fine gold is found among this clay,
and the heavier particles beneath it, upon the bed-rock. This stratum
varies in thickness from eighteen inches to eight or ten feet, while
the whole lead varies in width from a hundred and fifty to five hundred
feet.

"The same lead has been found at Sebastopol, four miles above Monte
Christo, and also higher up among the mountains. It appears at Monte
Christo, which is four miles above the high-lying Downieville, and over
three thousand feet above it, and at Chapparal Hill on the side of a
deep ravine; then at the City of Six, which is also on very high land,
about four miles from Downieville, across the North Yuba. It is next
found at Forest City, on both sides of a creek, and is there traced
directly through the mountain to Alleghany Town and Smith's Flat, on
the opposite side. There it is again cut in twain by a deep ravine. It
crops out on the other side at Chip's Flat, where it has been followed
by tunnels passing completely through the mountain to Centreville and
Minnesota on the other side. Here it is obliterated by the Middle Fork
of the Yuba, but it is believed to be again found at Snow Point, on the
opposite side of the river, and again at Zion Hill, several miles
beyond. There is no reason for doubting that after thus reaching over
twenty miles, it still extends further. Hundreds of tunnels have been
run in search of it. Where the line it follows was adhered to, they
have always found it, and have been well rewarded for their labor.
Millions of dollars have been taken from this lead, and its richness,
even in portions longest worked, is yet undiminished. These tunnels
have cost from $20,000 to $100,000 each, and interest in the claims
they enter sell readily at from $1,000 to $20,000, in proportion to the
amount of ground within them remaining untouched, and the facilities
which exist for working it. Many of these claims will yet afford from
five to ten or more years' profitable labor to their owners, before the
lead itself within them is exhausted. As in some of them quartz veins
and poorer paying gravel have been found, many of them may be valuable
to work from the top down as hydraulic claims."

This idea that the blue lead occupies the bed of an antediluvian river
is however not universally accepted. Mr. B. P. Avery, who has written
numerous newspaper articles upon the mineral deposits, asserts that the
"blue lead," as it is called, is not a "lead" but an extensive stratum
which is many miles wide, and is found all the way from the foot hills
to the summit of the Sierra Nevada. In reply to this, it is said that
while a bluish stratum of clay similar to that of the blue lead is
found over a wide district, that it is evidently different in origin
from the blue lead itself, which is confined to a narrow bed, and
marked by the signs found in all the other ancient river beds of the
state.

The Sierra Butte Quartz Mining Company has some of the best auriferous
quartz lodes in the state. One lode called the Cliff Ledge, is
twenty-five feet wide; and another called the Aërial Ledge, is about
three feet wide. In the Cliff Ledge, the paying rock averages about six
feet in thickness next the foot wall. The average yield is eighteen
dollars per ton. The quartz is bluish white in color, and very hard
when first taken from the lode, but on exposure to the air it slowly
crumbles into sand.

_Yuba and Butte._--West of Sierra county, and drained by the same
streams, is Yuba, which reaches to the Sacramento River, lying half in
the mountains and half in the plains, the mining district being in the
former half. The principal mining towns are Camptonville, Timbuctoo,
Foster's Bar, Texas Bar and Long's Bar. In 1859 there were nine
quartz-mills in the county, three at Brown's valley, and one each at
Camptonville, Dobbin's Ranch, Dry Creek, Honcut, Indiana Creek and
Robbin's Creek. The assessor in 1860 reported only two quartz-mills in
the county. There are twenty-two ditches in the county, with an
aggregate length of nine hundred and fifty-two miles, an average of
forty-three miles each. The most important ditch, called "Bovyer's,"
supplies Timbuctoo with five thousand inches of water in the winter,
less in the summer. The diggings at Timbuctoo are in a deep hill, which
is washed away by the hydraulic process.

West of Yuba and Plumas counties lies Butte, which is drained by the
Feather River. The principal mining towns are Oroville, Bidwell's Bar,
Forbestown, Natchez and Whiterock. In 1859 there were seventeen
quartz-mills in the county, of which four were at Oregon Gulch, at
Columbiaville and Hansonville, three each, two at Yankee Hill, and at
Evansville, Gold Run, Long Bar, Nesbitt's Flat and Spring Valley, one
each. The assessor reports for 1860, twenty-nine quartz-mills, worth
fifty thousand dollars, and crushing in the aggregate one hundred and
sixty-two and a half tons per day. There are sixty-four mining-ditches,
with an aggregate length of five hundred and eighty-three miles. The
bars and beds of Feather River were once very rich, and some of the
most extensive enterprises of river mining in the state have been
undertaken within the limits of Butte county. The greatest flume ever
built in California was that of the Cape Claim Company, near Oroville,
in 1857. It was three quarters of a mile long and twenty feet wide, and
furnished employment for two hundred and fifty men from May till
November. The expenditures during that period were $176,985, and the
receipts $251,426, showing a clear profit of $74,441. The next year,
after the water had fallen, the company commenced its labors again;
spent $160,000 and received $115,000, and thus lost $45,000. North of
Oroville is a "table-mountain" with a top of basalt, covering a rich
deposit of auriferous clay.

_Nevada and Placer._--South of Yuba and Butte is Nevada, the richest
mining county of the state. Within its limits the tom, sluice,
under-current sluice, and crinoline hose were invented, and the ditch
and hydraulic power were first applied to placer-mining; and
quartz-mining was first undertaken extensively. In 1859 there were
thirty-two quartz-mills in the county, and twenty-eight mining-ditches,
with an aggregate length of three hundred and ninety-four miles. No
part of the mineral region of the state is better supplied with water
than Nevada county. The richest quartz district is in the vicinity of
Nevada City, which has fifteen mills, and Grass Valley, five miles
distant, has seventeen. The great Allison mine, which has the richest
lode in the state, is in Grass Valley.

The quartz mines here are much troubled with water, and during the
winter of 1860-61, many of the mills were compelled to stop for weeks
until the shafts could be drained by steam engines, after having been
filled by a long and heavy rain. The annual gold yield of Grass Valley
has been estimated at four millions of dollars. North San Juan has the
finest hydraulic claims, and Sweetland the largest tail-sluices. The
Eureka Lake Ditch Company has more ditching and water than any other
company in the state. Their main ditch is seventy-five miles long, and
there are one hundred and ninety miles of branches, making a total of
two hundred and sixty-five miles, which have cost nine hundred thousand
dollars. The daily sale of water is six thousand inches, with a weekly
income of six thousand dollars. The principal mining towns are Nevada,
Grass Valley, North San Juan, Rough and Ready, Orleans Flat, Moore's
Flat and Humbug City.



INDEX.


                                   PAGES.

Chief Industry                       3

Metals obtained                      3

Gold Mines                           3

Placer Mines                         5

The Sluice                           7

Amalgamation                         9

Cleaning up                         11

Riffle-Bars                         12

Double Sluices                      13

Rock-Sluices                        13

Hydraulic Mining                    14

Blasting                            16

Tail-Sluice                         16

Tunnel-Sluice                       17

Ground Sluice                       17

Long Tom                            17

Cradle                              18

Pan                                 20

Dry Washing                         22

Dry Digging                         22

Puddling-Box                        22

Quicksilver-Machine                 23

Tunnel-Mining                       23

Shafts                              24

River-Mining                        24

Beach-Mining                        26

Mining-Ditches                      27

Prospecting                         27

Quartz-Mining                       27

Distribution of Gold in Quartz      28

Prospecting Quartz Rock             30

The Divining Rod                    31

Quarrying Quartz                    31

Arastra                             32

Chilean Mill                        34

Stamps                              34

Separation                          34

Sulphurets                          36

Chief Quartz-Mills                  36

Silver Mining                       37

Quicksilver Mining                  38

Platinum                            39

Del Norte and Klamath               39

Siskiyou                            40

Trinity and Shasta                  40

Plumas and Sierra                   41

Yuba and Butte                      43

Nevada and Placer                   44





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