The Hydraulic

Gold Miner's Manual

T.S.G.KIRKPATRICK

UC-NRLF

LO
ID

ADVERTISEMENTS.

^StKJfc^faS,-

REESE LIBRARY

UNIVERSITY OF CALIFORNIA.

Deceived fa&/ ..1900.

Accession No. ft 3 ZL Class No.

THE
NUMBER

PUMPS
SOLD
AND

WORKING

THAN

THAT

OF ANY

OTHER

MAKER.

Send for

Mining

Catalogue.

BIRMINGHAM.
GLASGOW.
MANCHESTER.
NEWPORT.
NEWGASTLE-
ON-TYNE.
SWANSEA.

WORTHINGTON SINKING PUMP, WITH

CHANNEL IRONS.
TA v ?* * TO. Catacitv. 160 ta iso zats. a min.

8
L

DUTIES.

To work

with

Steam,

Compressed

Air,
Electricity.

PARIS.

BERLIN.

BUDA PEST.

BRUSSELS.

VIENNA.

MILAN.

NAPLES.

CALCUTTA.

JOHANNES-

BURG.
SYDNEY.
AMSTERDAM.
ST. PETERS-

BURG.
COPENHAGEN.

ADVERTISEMENTS.

WORTHINGTON PUMPS FOR ALL SERVICES.

THE WORTHINGTON SINKING PUMP.

^ : s rr

The Sinking Pump

?; -- !' :> *

heavy pots, and are

shown on these two

ibflfipl . ;' \ made accessible for

pages is designed for

S=fll jteHii '.' iA : u

examination or repairs

working vertically in

. .jjiBn^fll r "*J--' r

by means of swing

sinking mine shafts, re-

' Vl^lH. Si'-."

bolts.

covering flooded mines,

-''JI^KsHBH -- 1

The fact that this

and for mine-pumping

.'? IjBjjM^" '

pump is duplex, and

work requiring the use

1 ip

fitted with the Worth.

of an efficient steam
pump, which shall be
positive in its opera-

ington valve motion,
makes its operation
positive. It is always

tion, quiet in action,

ready to start, and

compact in its design,

"l^m^n

when running there is

thereby occupying the

' ' ^tPi^S H ; " ' 1

an entire absence of

least possible amjjunt

s *^'isiiffllBI- : '' ; i

the concussive action

of space, and built in

' ' ''^^^^B '' F : :: '

which results from the

the strongest manner,

use of single pumps,

so as to withstand the

and which often causes

hard usage to which

; . : : ' ' |

serious trouble and

pumps on this service

firiE 31 ' Iff # , :

annoyance by bursting

are, as a rule, sub-

" .' '' m~jf. : ~'i -.'

the column pipe.

jected.

^Lf'fffi 1^6^ i

Being self - contained

The water plungers

'" ' ' C^^^u I

and working with per-

are double - acting,

fect smoothness, the

working through ex-

..-.. ; 1 j Sj : '

strain on supports is,

terior stuffing - boxes

: ' ' ^immri Irnl ' "-.

of course, reduced to

and adjustable packing.

I ' 1

a minimum.

The suction opening

The advantages pos-

is at the lower end of

sessed by this pump,

the pump, which is the

therefore, cannot be

most convenient place

over-estimated, and in

for attaching the suc-

all situations where

tion pipe or hose. The

promptness and reli-

discharge connection

!* ?i~^-tj^ ligB 1 ' ''

ability of action are re-

to column pipe is at

' ^^H

quired, it will be found

the back. The water

- ' I

perfectly adapted for

valves are enclosed in

the work.

r --? "^

|j ' "" "

SIDE VIEW OF WORTHINGTON SINKING PUMP
WITH CHANNEL IRON.

iii

ADVERTISEMENTS.

W, H. MARLING,

MATHEMATICAL DRAWING AND SURVEYING
INSTRUMENT MANUFACTURER,

47 FINSBURY PAVEMENT, LONDON, E.G.

And GBOSVENOR WORKS, HACKNEY, E.

TELEGRAMS: "CLINOGRAPH, LONDON." ESTABLISHED 185:

BARLING'S SPECIAL SURVEYING AND MINING ANEROIE

Giving Readings to Single Feet of Altitude.

No. 1086. Stout bronze metal cast
3$ inches diameter, silvered metal dia
Vernier scale, moved by rackwork motioi
Reading lens arranged to traverse the entir
circle. Altitude scale to 6000 feet. Com
pensated for temperature. In sole leath"
sling case, 5 15s. (Code Zoological)
No. 1087^-Ditto, ditto, same as
1086, but 5 irithes diameter, giving n.
open divisions, 6 (Code, Zoomorphic).

This instrument has been designed ah
constructed specially for the purpose c
readily ascertaining slight variations i
gradients, levels, etc., and from its extrem
sensitiveness will be found of considerabl
utility in Mining and Surveying wor
generally.

Besides extreme sensitiveness, the spc
ciality claimed for this Instrument is a
arrangement of the scale of Altitudes whic
admits of subdivison by a Vernier, hithert
impracticable, owing to the Altitude Seal
in ordinary u*e being a gradually diminish
ing one, to which a Vernier cannot I
applied. In the present instrument th
action has been so adjusted as to giv
accurate readings upon a regular scale c
Altitudes, the barometrical Scale of incne
having been made progressive so as to affor
the correct relative readings with the Seal
of Altitudes, so that the arrangement in n
way interferes with its use as an ordinar
barometer.

For Mining purposes the entire circle of the dial is graduated to represent 6 inches of the mercuria
column i.e. from 27 to 33. This scale will register about 2000 feet below sea-level to 4000 ieet above
the divisions of the Altitude Scale represent 10-feet measurements, which can be again subdivided, I
the Vernier Scale, to single feet. The Vernier Scale is moved by a rackwork adjustment, and
magnifying lens which rotates on the outer circumference of the Instrument facilitates the readin
of minute quantities.

No. 710a. MAHOGANY CASK, 8 inches by 6i by ij, containing, 6-inch electrum compass, A
double knee-joints and needle points, ink and pencil points, and lengthening bar improved hair-spru
divider improved pattern ink and pencil bows, with needle points set of three spring bows, wit!
needle points two drawing pens pricker 6-inch ivory protractor 6-inch ivory scale, 3 16s. 6d

No. 711a. MAHOGANY CASE, as above, but fitted with plain steel points with compass, bowt
and spring bows, 3 8s. 6d.

HARLING'S IMPROVED SOLID METAL ROLLING PARALLEL RULES,

In Mahogany cases, the wheels run on adjustable centres.

12-in. 18-in. 24-in. 30-in.

s. d. x. d. s. d. s. d.

Solid Brass .... 20 34 44 75

,. Gun Metal .... 23 38 50 90

Illustrated Catalogue of Surveying and Drawing Instruments Post Free.

W. H. HARLING, 47 FINSBURY PAVEMENT, LONDON, E.c

THE

HYDEAULIC
GOLD MINEE'S MANUAL

T. S. G. KIEKPATEICK

M.A. OXON.

CHAIRMAN OF THE ORITA GOLD MINES, LIMITED; DIRECTOR OF THE GOLDEN

GATE ALLUVIAL SYNDICATE, LIMITED; DIRECTOR OF THE

GRAVEL GOLD MINES OF COLOMBIA, LIMITED

WITH ILLUSTRATIONS

SECOND EDITION, REVISED AND ENLARGED

JJJR&SgR^

E. & F. N. SPON, LIMITED, 125 STRAND

SPON & CHAMBERLAIN, 12 CORTLANDT STREET
1897

3 #3 7

PBEFACE

THE SECOND EDITION.

THIS work was originally intended for Mining Elevated
Banks by means of Hydraulic Pressure, but as of late so
much attention has been attracted to Kiver and Placer
Mining, some few pages have been added giving hints
which will be found useful to those who embark on these
latter experiences ; and also a short table of the gems and
precious stones which commonly accompany gold in
river beds, and which from ignorance on the part of the
worker are often overlooked. The main facts, modified
by circumstances, remain the same for the treatment of
the auriferous sands from whatever source they are
derived.

July 20, 1897.

PBEFACE

THE FIKST EDITION.

THE following pages are intended to serve as a prac-
tical handbook of reference for the Hydraulic Miner.

Sufficient data are given to enable any one who has
a competent knowledge of pick-and-shovel work, and of
the use of carpenter's tools, to construct the necessary
plant for successful Hydraulic Mining.

The ditches and sluices are laid out on a scale suffi-
cient to move from 2000 to 5000 tons of " pay dirt " in
the 24 hours, and are the result of experience gained
in the management of very successful undertakings.

The measurements and estimates are furnished by
Mr. W. S. Welton, the engineer who laid out the
" Colombian Hydraulic " gold mine.

The illustrations are from photographs taken by
Mr. Welton. The plans and sections are to scale.

The chemical and other notes are compiled from the
highest authorities on the subject, and have been prac-
tically tested by the Author.

LONDON, April 1890.

THE

HYDRAULIC GOLD-MINER'S MANUAL,

THE cheapest form of gold-mining is that in which the
precious metal can be removed from its associated im-
purities such as clay, gravel, sandstone and iron and
collected, entirely by the agency of water and mercury,
with a minimum of manual labour.

This can be done where there occur high banks of
gravel on to which water can be brought to play with
great force, so that by undermining the bank it falls
of its own weight, and is then washed into properly
constructed " sluices," where the mass becoming
disintegrated, allows the gold to assert its specific
gravity and deposit itself in the " riffles " of the sluice.

Although the fauna and flora throughout the globe
vary owing to climatic influences, the geological types
are constant ; and the usual occurrence of " payable "
auriferous gravel is in the channels of antediluvian
rivers, long since " dead," and which have been
upheaved, often many thousands of feet, above their
ancient level; the modern watercourses in most in-
stances taking an entirely different direction, and

TEE HYDRAULIC

frequently discovering the ancient channels by cross-
cutting, and denuding and exposing them in their
course.

Further than their existence as "channel-gravel,"
science has failed to penetrate the mystery of their
origin ; but it may be taken as an axiom that wherever
red (oxidised) gravel occurs within a measurable
distance of volcanic action, that gravel is auriferous.

The four essentials for successful hydraulic mining
are : '

1. Abundance of auriferous gravel.

2. Abundance of water.

3. A good dump.

4. A properly constructed sluice.

Gravel containing no more than 3d. or 4d per ton of
gold will pay large profits.

Water. This must be brought to the top of the
bank at an elevation considerably above the height of
the bank, by means of an open ditch, and delivered
into a reservoir or " bulkhead," from which it passes
down in a close-riveted iron pipe of boiler plate of
2 feet or more diameter (according to the quantity
of the supply), tapering down to say 18 inches before
it arrives at the " monitor " or distributing machine
by which it is thrown (exactly as in the case of a fire
engine) against the bank.

Sluice. The sluice must be constructed on the
" bed-rock " on which the gravel deposit rests ; and be
brought as close to the bank as is safe, having regard
to the " fall of bank," which may endanger the machine
and those directing it.

E. if F. N. Spen, I

SLUICE.
Showing how the false bottom of blocks is put in;

GOLD-MINERS MANUAL.

Grade. The grade of the sluice is an all-important
consideration, and depends on the gravel bank
generally there will be found distinct layers of gravel,
interspersed with pipe-clay and sandstone; and evi-
dently deposited at distant intervals of time.

The top of the bank will probably be covered with
vegetation ; beneath which the gravel will probably be
very fine, and containing but little gold. This may
be succeeded by larger gravels, in varying strata,
alternating with sandstone, stiff red clay or hard
conglomerate, in very distinct layers, the latter
requiring (unless the water power be very large)
gunpowder or dynamite to break it down.

A safe grade to adopt (unless the boulders are very
large and the gravel very free) is one in thirty-
three ( r J. This is sufficiently rapid to allow the

\ oo /

gravel to travel down the sluice, get thoroughly washed
and disintegrated, and so set free the tiny particles of
gold mechanically mixed with it. In the case of large
boulders occurring, it is necessary to remove them
from the sluice by specially constructed ."forks," or if
too large to handle, by " derricks." All obstructions
roots, timber, &c. must be removed, to prevent choking
the sluice; as any overflow from a blocking of the
waterway would lose gold.

Having determined the best point of attack, the ditch
must be brought as near as possible, so as to avoid an
expensive outlay on (( piping," and the bulkhead must
be erected.

Ditch. A ditch 6 feet wide at the top, 3 feet at the

B 2

TEE ETDEAULIC

bottom, and 3 feet 6 inches deep, will carry some 2500
to 3000 " miner's inches " of water, according to the
rapidity of its grade.

Miner's inch of water. A miner's inch of water is
the quantity which will pass in 24 hours through an
aperture of a square inch under a pressure of 6 inches,
and is equal to 2190 cubic feet, or 12,960 gallons of
water, or about 58 tons weight.

Bulkhead. The bulkhead should be constructed,
10 feet by 5 feet by 10 feet high, of two thicknesses
of IJ-inch plank, with joints to overlap. The frames
of 9-inch by 9-inch rough timber cut on the spot.

The flume from the ditch enters the bulkhead at the
top. A screen across the centre prevents stones, bits of
wood, &c., from passing into the pipe, and so endanger-
ing the safety of the " monitor." An overflow also at
the top allows the surplus water to escape. A man-
hole at the bottom of one of the sides enables the sand
and dirt to be cleaned out when necessary.

Sluice. The bottom of the sluice should be of five
planks, 1J inch thick by 11 inches wide ; the sides of
two planks, 1^ inch by 11 inches wide. The joints should
fit perfectly true ; and if slightly open, the open part

should not be on the top ^simfsgsa^xsmmsm thus, as gold

and mercury would drop in and not be easily
got out, but the planks should join tight at the top

thus, and any imperfection in the joint

be underneath.

The frames should be of 6-inch by 4-inch timber, and

GOLD-MINERS MANUAL.

Q OLD-MINERS MANUAL.

the sluice should be lined on each side by two 11 -inch
by 1 J-inch planks, nailed to the sluice, to protect it ;
and the lower edge of this lining should be 1J inch
above the bottom of the sluice. This enables the
"riffle-strips," which separate the blocks forming the
false bottom, to be laid in and taken out easily.

Riffles. There are numerous methods of making the
false or " riffle-bottoms " for the sluices ; but, as timber
and saws are always available, I prefer as the best all-
round method (and which is not beaten by any other,
and can always be easily renewed when worn), blocks
10^ inches square and 8 inches deep, placed in the
bottom of the sluice, and separated by strips of wood
laid across the bottom of the sluice, of a section of
1J inch by 1 J inch. These should not be nailed ; but a
small wedge of wood will keep them from shifting, and
they can be removed with ease without damaging the
woodwork of the sluice ; as in the case if nailed
down and torn up on the occasion of each " clean up."

If there is no pipeclay intermixed in the gravel bank,
and the stuff disintegrates very easily and sets free the
gold rapidly, a steeper grade, say 1 in 24, may be
used in constructing the sluice ; but it seldom happens
that pipeclay is absent, and in that case it would travel
down the sluice without being sufficiently broken up
to set free the gold, and would, moreover, from its
natural adhesiveness, pick up any gold it might come
in contact with, and hurry it through the sluice and
out on the dump, where it would be lost, if too steep a
grade were employed.

For economical working it is better to make two

10 TEE HYDRAULIC

parallel sluices, so that when one is being cleaned up
the other may be working, as a great saving of time is
thus effected.

Pipe. The main pipe from the bulkhead may be
2 feet or more in diameter as it leaves the bulkhead,
and reduced to 18 inches in the first 100 feet. It should
be fitted with two vacuum valves ; as? in the event of
one of the monitors " blowing off," the pipe would
collapse from the sudden vacuum formed, were it not
for the valves. The 18-inch pipe should continue down
to the distributor, from which the water will be con-
ducted to the two monitors by two pipes of 15 inches
diameter.

Monitors. The two monitors of No. 5 size are fitted
with deflectors, and each with four nozzles, of 5 inches,
6 inches, 7 inches, 8 inches diameter, according to the
quantity and pressure of the water supply, and it is often
in dry seasons well to have a smaller size even than
5 inches, say 2 inches or 3 inches, so that the man in
charge may at any moment fit on that which is most
suitable for the water supply offering at the moment.

The double sluice (if two are constructed) should,
when within, say, 300 feet of the gravel bank, open out
into two single sluices ; and the monitors should be
placed in the fork of the two sluices, to work on either
side.

Messrs. Eraser and Chalmers, of Chicago, supply
excellent monitors, and they can also be obtained in
Glasgow, through Messrs. Duncan Bros., Engineers, of
Westminster, or Mr. George Green, of the Eoundry,
Aberystwith.

GOLD-MINERS MANUAL.

Arrangements should be made to have jrapid com-
munication with the man in charge at the canal dam or
pipe-head reservoir ; so that in case of an accident at
the mine, such as the blowing off of a nozzle or the
bursting of a pipe, the water may be immediately shut
off and the supply to the bulkhead stopped.

GRAVHL BANK

MODE OF OPENING A MINE.

The monitor is capable of being moved to the right
or left, or elevated or depressed, by an ingenious arrange-
ment of sockets requiring no exertion on the part of the
man directing it ; and it is counterbalanced by a box

TEE HYDRAULIC

p
g

GOLD-MINERS MANUAL. 13

filled with stones to compensate for the weight and
pressure of the water.

Undercurrent. At the lower end of the sluice a
grating of fire bars, parallel to the course of the sluice,
with half-inch interstices between them, enables the
water and fine particles to fall through the sluice, while
the larger gravel travels on from the impetus it has
acquired, and is precipitated in any direction desired
to the waste dump or ravine.

Bars. The bars for the undercurrent should be 5 feet
long, 6 inches wide and Ij inch thick, and should be
cast with the thin end upwards, so that any "blow-
holes " from imperfect casting should be underneath
when the bars are in position, while the upper surface
will be harder, more perfect and more durable.

The " smalls " fall with the water on to a sloping
channel which takes them to the undercurrent, the
force and direction of the muddy mass being controlled
by a number of lozenge-shaped pieces of wood fixed on
a pivot which can be turned by the overlooker, so as to
spread the current evenly over the undercurrent.

The length and width of the undercurrent depend on
the facilities of the locality. A good arrangement is
one of 12 feet wide and 50 feet long; the bottom is
blocked exactly as in the sluice, but the section of
the strips may be reduced to 1 inch. The worn
sluice blocks from the main sluice work in very
economically for the undercurrent, as owing to the
light matter passing over them in this place there is
very little wear and tear.

The water and mud from the tail of the undercurrent,

TEE HYDRAULIC

if it is considered to be " free of gold " and not worth
putting over a second undercurrent, can be utilised by

PLAN OF UNDERCURRENT.

CRATING

GOLD-MINERS MANUAL. 15

diverting it to assist the passage of the large stones
into the ravine.

Grade. The grade of the undercurrent should be
much steeper than that of the main sluice ; and not,
as has been popularly described in some works (whose
authors can have had no practical acquaintance with
the subject), a less steep grade ; for the result of one
built on such principles, however much it may at first
sight commend itself, will in practice be found to be
absolutely useless, and will result in the settling of
the fine sand and slimes on the blocks, and the entire
disappearance of the undercurrent within 48 hours !

Experience on the spot will decide, from the character
of the smalls, what grade to adopt. It may vary from
18 inches to 8 inches in 12 feet (that is, from 1 inch in
18 inches to 1 inch in 8 inches).

Tailings. The overlooker must carefully examine
the tailings to see that no gold is being carried off, and
must either alter the grade or lengthen the undercurrent
to meet the circumstances.

He should also keep an eye on what is passing over
the grating, as it is always possible that nuggets too
large to pass between the openings of the grating may
be contained in the gravel, which would of course be
lost if permitted to fall over into the dump. Their
specific gravity will cause them to travel much slower
than the gravel, and an experienced eye would at once
detect and rescue them.

Bed-rock. It will be obvious from the above that
the importance of laying the sluice on "bed-rock"
cannot be over-estimated.

16 TEE HYDEAULIC

Whether the bed-rock on which the gravel deposit
reposes be slate or granite, is immaterial in regard to
this cardinal question.

To break down the bank of gravel and then permit
the washed material to travel over a gravel bottom
before reaching the end of the sluice, would be to
allow the gold to hide itself in the gravel and be lost ;
while, if it passes over granite, the smooth nature of
the rock assists its progress to the sluice; and if over
slate, the natural rugosity of that formation detains it
in its crevices and it is easily seen and removed.

The proper point at which the gravel bank should
be attacked having been ascertained by a careful survey,
and, if necessary, by the driving of trial adits to discover
if possible the centre of the old river channel (which
will contain the richest gold in the deposit), the bulk-
head and pipes, together with the monitors, having been
completed, and the sluice constructed, the water should
be turned on and allowed to flow through the sluice
for a day or two, carrying with it any poor gravel that
can be conveniently played upon, so that the wood of
the sluice should swell and fit tight, and any interstices
existing should be filled up before commencing serious
operations.

The Run. When all is ready, the full power of the
water is directed at the base of the bank, and, according
to the yielding property of the gravel, the whole super-
posed mass will fall on to the bed-rock in the course of
a few hours. The water is then directed on the fallen
mass, and the muddy torrent is guided by the workmen
to the mouth of the sluice.

GOLD-MINERS MANUAL. 17

This operation continues without intermission, night
and day, for 20 or 30 days, until the manager judges
that he has a sufficient amount of gold collected in the
sluice to make it worth while to " clean up."

After the first two days' running, he will have poured
into the upper 150 feet of the sluice, five or six bottles
of mercury, say 400 Ibs. weight.

The fine particles of gold dissolve in the mercury,
which lodges in the interstices between the blocks ; of
course the warmer the temperature the more rapid is
the action of the mercury in seizing the gold, as when
water approaches the freezing-point mercury becomes
very sluggish but as it can find its way through
infinitesimally small apertures, the importance of
making the sluices as closely fitted as the finest cabinet
work becomes apparent; and the great importance of
clearing away any obstructions which may occur in
the channel of the sluice will exercise the vigilance of
the manager.

Clean up. The period for the clean up having
arrived, the supply of water from the ditch is dimi-
nished to a quantity which will cover the bottom of the
sluice to a depth of 3 or 4 inches-, and it is allowed to
run clean for an hour or two before the work of taking
up the blocks is commenced*

Each series of blocks, commencing at the head of the
sluice, is then removed, together with the dividing strips ;
and each block is carefully washed in the sluice before
stacking at the side.

The manager then enters the sluice, and takes up,
in a scoop of a special form, the mercury, which shows

18 THE HTDEAULIC

as the fine gravel is rolled down by the clear water.
Each time that he takes up the mercury, and the gravel
which comes up with it, he presents the mouth of the
scoop to the current, and bj- a dexterous turn of the
wrist, he " vans out " the gravel, leaving only the mer-
cury in the scoop. He must carefully examine any
gravel which remains towards the end of the vanning
operation, to see if, as its weight and reluctance to leave
the scoop would indicate, it has any gold mechanically
attached to or encrusted in it. Having picked these
pieces out, he pours the mercury into a small iron
bucket, fitted with a tripod stand sufficiently high
to keep it well above the water in the sluice, and
recommences. This operation is continued until he
has picked up all the mercury in the sluice, and may
occupy five or six hours.

The buckets, with the mercury contained, are carried
to the counting house as they are filled. The blocks
and strips are then replaced in the sluice, any
necessary repairs or alterations in the structure are
completed, any additional lengths required to advance
the sluice in the direction of the receding bank are
fixed, and the operation of washing for another " run "
is recommenced.

In case the sluice has been made a double one, the
operation of the monitor is continuous, and much time
lost in cleaning up is economised.

At many mines the whole length of the sluice,
together with the undercurrent, is only cleaned up once
in three months. Only the upper 300 or 400 feet is
each month taken up ; by which means the " crop-

GOLD-MINERS MANUAL. 19

ore " is removed monthly, and an accumulation of the
finer ore in the lower portion of the sluice swells the
amount of the three-monthly return.

Instead of parallel sluices, a branch sluice brought in
to join the main sluice some few hundred feet down
from its head, is often a convenient arrangement ; but
details such as these must be left to the judgment of
the manager on the spot.

The collected mercury is easily washed clean from
the small remaining amount of gravel floating on it,
and is then squeezed through chamois leather or very
close woven linen, by which means the golden amalgam
is retained as a hard mass in the leather or cloth,
while the unsaturated mercury escapes through the fine
orifices and is returned to the bottles.

The amalgam will be found in practice to contain
from 30 to 36 per cent, of its weight in gold.

Retorting. The mass is then placed in the retort.
The furnace heat drives off the mercury, which is
condensed by wet cloths, or a water-jacket, placed
round the tube, and the mercury drops into a bucket of
water. Care must be taken that the nose of the tube
does not enter the water, or a vacuum would be created
in the retort and an explosion would follow.

When all the mercury has been driven off and the
retort cooled, the mass of gold is taken out and melted
in a plumbago crucible with a small amount of borax,
or preferably neutral borate of soda, to free it from any
impurities. It is then poured into the ingot moulds,
and, when cool, weighed and despatched to its desti-
nation.

c 2

20 TEE HYDRAULIC

It will be seen from the above account that the whole
process of collection of the gold is exceedingly simple,
economical, and requiring no scientific knowledge, good
judgment in the laying out of the ditch and sluice being
the main factor in successful hydraulic mining, coupled
with vigilant attention to the continuous operation.

Night Lighting. With the large water supply at
the mine, it is easy to erect the necessary plant for
electric lighting at night ; and this will be found an
outlay that will soon repay itself.

Dump. It is scarcely necessary to draw attention to
such an evidently important factor in the success of the
mine as the dump or receptacle for the waste washed
gravels. As a large mine washes from 2000 tons per
day, upwards, the ground must be chosen for the tail of
the sluice where millions of tons can be got rid of
without blocking up the outlet. A ravine of great
depth, or a rapid and storm- washed river bed, which
does not interfere with " vested interests," should always
be preferred.

Ditch Building. For the construction of the ditch
the following will be found a very close estimate, the
labour being calculated at sixpence per hour for good
labour :

Eock . s. d.

Excavating 20

Wheeling 09

Dressing .. .. .. .. 09

Superintendence .. .. .. 06

TOTAL . . . . 40 per cub. yard.

GOLD-MINERS MANUAL.

Gravel and clay :

Excavating and wheeling ..
Levelling ditch
Making up removed material
Superintendence, &c.

TOTAL

s. d.

1
6

2 6 per cub. yard.

Total cost, at 4 cubic yards excavation per yard run :

s. d.

Rock .. 1| cub. yd. at 4s. Od. .. 60
Gravel . . 2 J at 2s. Qd. . . 63

TOTAL

12 3 per yard run.

Or = 1078J. per mile.

22 THE ETDEAULIO

PRO FORMA SPECIFICATION OF STORES EEQUIRED FOR
OPENING AN HYDRAULIC MINE.

10 cwt. -|-inch borer steel.

1 dozen steel mallets for boring, 7 Ibs.
12 hand-saw files.

3 tenon-saw files.
15 6-inch pit-saw files.
15 8-inch cross-cut saw files.

3 smith's sledge-hammers, 9 Ibs.

1 cwt. cast steel for steeling picks.

1 dozen riveting hammers.

1 dozen set tools for J-inch rivets.

1 dozen snap tools.

6 hand-hammers, Nos. 10 and 12 tester heads.
10 dozen miner's steel shovels, diamond points.

5 dozen Cornish picks.
10 dozen handles for ditto.

1 dozen long Colonial pattern felling axes.

2 small portable forges.

1 best black staple smith's vice.

2 anvils (farrier's pattern) 150 Ibs. each.

2 grindstones 27 inches diam. (1 coarse, 1 fine).

2 sets screw stocks, dies, taps, and wrenches com-

plete, from -^g-inch to f-inch and J-inch to 1-
inch, engineer's.

3 expanding spanners.

20 cwt. best cut nails 2J inches.
10 cwt. 3

GOLD-MINERS MANUAL. 23

16 cwt. best cut nails 4 inches.
4 cwt. 4tL
4 cwt. 5
4 cwt. spikes, 7 inches.
4 cwt. 9

1 dozen riveting blocks.

2 dozen pairs of tools for riveting pipes.
500 lugs for ditto.

4 sets carpenters' bench planes (jack, trying and

smoothing).

4 3-inch bench screws and nuts.
6 4-lb. carpenter's axes, with handles.

2 sets socket mortise chisels, with handles.

3 pair 12-inch wing compasses.
6 2-foot rules to fold 12 inches.

9 &

a ?? j? j? u

4 carpenter's set stones.
2 pair pincers.

2 2-foot iron squares, graduated inches.
4 14-inch carpenter's plated squares.

4 6-inch

4 dozen carpenter's pencils.

3 spirit levels, set in straight edge, 30 inches long,

with handle on top to protect level.
6 hand-saws (7 teeth to inch).

4 fine ditto, for cross cutting.
4 carpenter's table saws.

3 12-inch tenon saws.

4 7-foot pit saws (for pine) ) complete with
6 5-foot cross-cut saws -(for oak) j bow and gear.
2 iron braces, 24 bits to each.

24 TEE ETDEAULIC

4 carpenter's marking mortises.

4 hand-saw sets.

6 pit-saw sets.

6 14-inch drawing knives.

3 plated spokeshaves.

6 12-inch turnscrews.

2 ploughs and irons.

6 adzes (12-inch handles).
6 J-inch screw augers.
6 f -inch augers.
6 -|-inch augers.

6 IJ-inch augers.

3 1^-inch augers.
3 IJ-inch augers.
3 2-inch augers.

3 dozen caulking irons, singla crease.

4 plated angle bevils.

2 joiner's cramps, 6 feet long.
60 feet of 1^-inch bar iron.
130 Ibs. soft iron wire, No. 12 B.W.G.

1 cwt. white lead.

16 door locks (different).

2 dozen padlocks.

5 dozen 4-inch butt hinges.
2 gross IJ-inch screws.

1 gross 1-inch screws.

7 gross smaller (for locks).

10 pieces of unbleached calico (for making tight
joints in pipe).

2 dozen ordinary iron buckets.
2 dozen black iron scoops.

GOLD-MINER'S MANUAL.

1 dozen hard brushes.
20 bottles mercury.

2 No. 5 " monitors," with deflectors and nozzles, as

described in text.
2 18 -inch vacuum valves.
2500 feet 18-inch diameter pipe, No. 14 B.W.G., i-inch

rivets.
500 feet 15-inch diameter pipe, No. 14 B.W.G., J-inch

rivets.
100 feet 30-inch diameter, tapering to 18 inch, No. 14

B.W.G., and J-inch rivets.

2400 feet run of 11 -inch by 3 -inch timber, cut into
11-inch by 1^-inch, in 20-22-feet lengths, second
St. Petersburg deals.
4000 feet run 6-inch by 4-inch in 12-22-feet lengths,

third St. Petersburg deals.
1 small distributor.
Melting pots, ingot moulds.

Chemicals borax, carbonate of potassa and soda, &c.
Tongs, cobbing hammers, and iron plates.
Blankets, cold chisels, scales and weights.
Eed lead, litharge.

The cost of the above will be under 2000.

26 THE HYDRAULIC

THE FOLLOWING NOTES WILL BE FOUND USEFUL FOR
KEFERENCE.

A miner's inch of water should move from 2 tons to
2J- tons of gravel per day of 24 hours.

A gallon of water weighs (roughly) 10 Ibs.

A cubic foot of water weighs (roughly) 60 Ibs.

One horse-power (I.H.P.) raises 150 Ibs. 220 feet
high in a minute for 8 hours daily, and can draw
4480 Ibs. ( = 2 tons) horizontally, and is equal to
7 men.

5 men working 10 hours = 1 horse working 8 hours.

For computing work, 14 cubic feet of granite may be
taken to represent 1 ton.

A centner =114 Ibs.

A litre = If imperial pints.

A kilogramme = 2 Ibs. 8 ozs. 4J dwt. avoirdupois.

A gramme = 1 cubic centigramme, and weighs 15 * 434
grains troy.

A kilometre = 5 furlongs.

Charcoal and coke produce about equal amounts of
heat ; but, owing to the greater bulk occupied by char-
coal, coke produces most heat in a given time.

Eau regale, the only acid which dissolves gold, is one
volume of nitric mixed with three volumes of hydro-
chloric acid (more or less).

All metallic nitrates are soluble in water.

The chlorides of silver and mercury are the only
metallic chlorides insoluble in water.

GOLD-MINERS MANUAL. 27

Chloride of lead is nearly insoluble in neutral brine,
but very soluble in acidulated brine.

Most metallic sulphates are soluble in water, except-
ing those of lead, strontium and baryta. Alkaline
carbonates are the only carbonates soluble in water, and
are the only ones undecomposable by heat alone, but all
carbonates are decomposable by heat with the addition
of carbon. Alkaline silicates, with a great excess of base,
are the only silicates soluble in water.

All rocks not calcareous are silicious.

The melting point of gold is about 2000 Fahrenheit,
or 1100 Centigrade.

Formula to convert a degree of Fahrenheit to Centi-
grade, and vice versa :

5(F ' 32) = Centigrade. ^ + 32 = Fahrenheit,
y o

To find the specific gravity of a stone :

Divide the weight in air by the loss of weight in

water of the temperature of 60 Fahr. The quotient is

the specific gravity.

e.g. Quartz Crystal in air = 293 * 7 grains.
in water = ISO'l

113 -6 grains.

which is the specific gravity of quartz.

^ UNIVERSITY

28 TEE ETDEAULIC

An excellent fire lute is made of 8 parts of sharp
sand, 2 parts of good clay, 1 part horse-dung ; mix, and
temper like mortar.

An English sovereign weighs 123*274 grains, and
contains of pure gold 113 grains.

An English shilling weighs 87*27 grains, and con-
tains of pure silver 80 727 grains.

For approximate calculations

A grain of gold may be taken as 2d.
A dwt. of gold may be taken as 4s.

A dwt. of gold in a cwt. of ore = 1 oz. of gold per
ton of ore.

Assaying. To assay gold quartz

take 200 grains ore.

500 litharge.

6 lampblack.
500 carbonate of soda.

Or, another way

200 grains ore.

200 red lead.

150 carbonate of soda.

8 charcoal.

6 borax.

Mix and put into warmed crucible, and cover with
half an inch of common salt; fuse in a hot fire 30
minutes ; cool, and break the pot ; clean the button
with a small hammer.

GOLD-MINERS MANUAL. 29

If the quartz is very pyritous

take 1000 grains and calcine "dead" without
clotting.

Add 500 grains red lead.
35 charcoal.
400 borax.
400 carbonate of soda.

Cover with salt and proceed as above.

In each case cupel the button.

As the bone ash of which the cupel is made can absorb
its own weight of metallic oxides, the cupel chosen
should always exceed the weight of the button to be
operated on, so as to have a margin. Boil the gold prill
obtained from cupelling in nitric acid, which dissolves
the silver and leaves the gold pure.

The above formulae are open to modification by the
operator according to the apparent richness or poverty
of the ore to be treated, and the presence and character
of the basic impurities. In case there are oxides, a
reducing agent is required ; and if sulphides, an oxidising
agent.

As a rule employ a weight of litharge twice that of
the ore, and of carbonate of soda the same as the ore.
These reagents are added to control the size of the lead
button, and to obtain one of a suitable size for cupelling.

Mercury. Great attention should be paid to the
condition of the mercury before putting it into the
sluice. As purchased it is seldom pure, and in that
case is unable to seize the gold.

Mercury absorbs oxygen from the air, which forms

30 TEE HYDRAULIC

with it a very slight covering over the metal, but quite
sufficient to prevent its combination with gold, as there
is no actual contact of the two metals. This pellicule
can be removed by pouring out the mercury, and passing
a large and very dry glass tube over its surface. Turn-
ing the tube gently the oxide skin adheres to the glass,
and is easily removed. Moreover, the mercury of com-
merce is seldom free from metallic impurities, and mere
redistillation does not get rid of these. If the mercury,
after distillation, be put back into its iron bottle, and
nitric acid, mixed with double its volume of water, be
added, and the whole heated to say 150 degrees Fahren-
heit, a certain amount of nitrate of mercury is formed,
and this, together with the free acid present, reacts
on and dissolves the foreign metals, as well as any small
amount of oxide of mercury which has been formed by
the contact of air during distillation. Leave the acid
in the bottle for 24 hours, shaking it well from time
to time. Then drive off the water by gently heating
the bottle. A crust of nitrate of mercury will cover
the surface. (This is easily removed, and the metallic
mercury can be recovered from it.) The mercury should
then be thoroughly washed with clean water. This
operation is well worth doing, and repeating, till the
purity of the mercury is ascertained beyond all doubt ;
as thousands of pounds are lost through the impurity
of the mercury purchased for mines.

If there be no metallic impurities present, but merely
oxidisation from contact with air, pour the mercury into
glass bottles and add a little concentrated sulphuric acid
(S0 3 ).

GOLD-MINERS MANUAL. 31

Shake the bottles till the mercury is broken up into
small globules, so that it can all come in contact with
the acid. This will remedy the trouble. After two or
three days, pour off the acid and thoroughly wash the
mercury with repeated fresh waters.

The purity of the mercury employed cannot be too
much insisted on, or too carefully watched, and is pro-
bably one of the points least considered and most
neglected while it is emphatically all-important.

32 THE HYDRAULIC

APPENDIX.

EIVER MINING.

THIS class of gold seeking can but in very few cases
be carried on continuously throughout the year, but is
mostly confined to the five or seven months of low
water, after the winter snows in the hills have been
melted.

In its simplest form, as in use for centuries by the
Hungarian gipsies, all that is required is a board 2 or
3 feet wide and 4 or 5 feet long, with grooves cut across
it transversely, or slips of wood wedged on across it,
with a wooden edge on each side, of, say, 6 or 8 inches
high at the upper end and 3 at the lower ; a cloth or
blanket is sometimes spread over it, but more often the
practice of the gold washer enables him to give the
board so accurately a graduated incline that he catches
all the gold without the assistance of such extraneous
aid. The heavier auriferous pebbles and the gold are
caught in the grooves or against the riffles. The board
is then tilted and the contents received in a common
severing-trough, the gold pebbles and rich sand care-
fully panned and the resulting " crop " melted into
small ingots. Two or three men keep up the supply

GOLD-MINER'S MANUAL. 33

of river sand and water, and the result even from poor
gravels is generally a fair wage for the time .occupied.

On a larger scale boxes 10 or 12 feet long, 1 foot or
18 inches wide, each fitting into the next, and each
riffled across twice or more in each length, will employ
more men, and if a rough sieve with IJ-inch holes be
placed over the upper 2 feet of the sluice, so as to get
rid of the larger stones, a more rapid grade can be given
and more work done. As a rule river gold is small and
heavy if from the led rock, but that on the sides is
lighter, flatter, floatier, and more liable to be lost by
rapid work.

It is almost invariably the case that gold is accom-
panied by a quantity of black sand, i.e. " magnetic iron"
from which it is very difficult to separate it except by
the aid of a magnet. If there are facilities for "furnac-
ing " the partially cleaned and enriched produce of the
sluice boxes, an enormously larger percentage of gold
would be obtained, as it is impossible by such rough
and ready practice to save the very fine gold ; but this
is a question which involves more capital than is often
available by the miner who follows " Gold Bushes."
^or raising the bed of the river on a large scale expen-
sive work has to be done : a dam, which must go down
to " led rock " (to prevent seepage), is the first essential ;
a channel must be cut to carry the river, returning its
water into its course lower down"; a foot dam, at the
lower end of the portion proposed to be laid dry, must
be built. Pumps to thoroughly drain out all seepage
from the dried bed must be erected, and derricks to
move the large rocks must be put in position. The

3d TEE HYDEAULIC

river bottom must be raised by elevators into the sluices.
All this requires power either derived from a head of
200 to 400 feet of water or from steam, and this means
considerable outlay.

Messrs. Eisdon, Ironworks, San Francisco, California,
have lately issued a catalogue containing a full account
and illustrations of a plant for elevating river beds, which
is the invention of Mr. Evans, the Mining Superinten-
dent of the Golden Feather Company of California, and
which is pronounced by all hydraulic engineers as far
the finest and most economical plant ever yet put to
work.

Dredging. Numerous plans have been tried for
dredging rivers where gold is known to exist, but when
these exist, facilities for turning the watercourse often
do not. What is proved in practice the most reliable,
and not liable to mishaps from encountering rocks
and disabling machinery, is the dredger, invented by
Mr. Charles Ball, of St. Leonards, Sussex.

It is well adapted for rivers with a fairly smooth
bed rock bottom not deeply indented with crevices, but
in every case when the use of it is contemplated, the
nature of the river bottom should be carefully investi-
gated, and above all the machinery should be put
together and tested before being sent to a place where
the smallest alterations cost a great expenditure of time
and money.

To return to the wants of the "Digger" Let him
take as little " impedimenta " as possible. A few tools,
such as saws of different sorts fitting into the same
handle, hammers, nails, screws, gimlets, chisels, picks,

GOLD-MINERS MANUAL. 35

together with scales and weights, a few melting pots
and chemicals, and he will probably be able to make
as good a living with these on the camp as by gold
digging. But above all, let him attend to the Provend I
and keep from " Drink"

"A SEASON'S GOLD DIGGING ON THE YUKON,"

We had still eighty miles to pole up Forty Mile before
we reached Franklin Gulch, the scene of our operations,
and a weary bit we found it. It was now all against a
strong current. In many places the water was com-
paratively low, and the boats had to be towed on, we
jumping from rock to rock with the line in our hands.
There were some compensations. The banks abounded
with small onions, just the size and flavour of English
spring onions, and these seemed delicious as a relish
with our unending bacon and bread.

Signs of mining now began to appear, but in no great
amount till we reached Franklin Gulch, a small streanj
issuing from a narrow glen, overhung with various
trees, and with moss covering the banks. Here were
encamped nearly sixty miners. The gulch has been
worked about four years, iand at different times has
yielded a good return to those who have understood
their work.

Our boats were now abandoned, and the morning
after our arrival we took the narrow track made by
the continual tramp of the miners up the gulch. But
all the line was apparently occupied. Everywhere

D 2

36 THE HYDEATJLIC

men were hard at the task of breaking up the bed of
the stream.' We had repeated offers of work, but
decided first to " prospect " the whole line. After
walking up-stream about four miles, it became evident
that no " claim " remained, and we resolved to return
and work for weekly wages.

We had left Chilcoot on March 21, reached the gulch
on June 26, and began work on the 27th. The fact is
that independent work on a claim is scarcely possible
the first season, unless the water in the creek itself is
very low, in which case a considerable sum may be
realised by the simplest form of gold washing. But in
the gulches great preparations must be made, which
generally occupy nearly an entire season. The claim
holder spends the winter on the spot, aud is ready at
the beginning of the second season to make practical
use of his apparatus. Each claim is 300 feet in length.
E"o one is allowed to occupy more, and this space is
staked off.

The manner of procedure is as follows : The stream
is danimed across, very much in the same way as for a
mill dam in England, and a side run for the overflow is
constructed close by the bank. This is termed the
flume. The bed of the stream is thus bared for some
40 or 50 feet. Water from the upper portion of the
flume is let into a wooden sluice by means of a trap
door which controls the water. This sluice is made
of a series of boxes, open at the ends, constructed
to fit into one another, and supported on props fixed
into the bed below. The sluice at first bends out of the
flume until it is parallel with it, and runs in this way

GOLD-MINERS MANUAL. 37

for the Ml length of that portion of the claim which is
being worked. In each box two smooth poles are laid
side by side, fitting the breadth of the box exactly, and
across the ends of these is fastened to the sides of the
box a piece of wood of exactly the same width and
depth as the cradles. The box is thus about half filled
up. Active operations then proceed as follows : two
men work at each side of the sluice boxes, one in front
of the other. I worked a front position. I had with
my pick to break up the bed, gathering out and
throwing aside the rough masses. The smaller sand
and pebbles I then shovelled into the box above me.
As the work proceeded and the excavations became
deeper, the up-throw was very hard work, the sluice
often being considerably above my head. The man
behind cleaned the bed rock, removing all particles
adhering to it, collecting and shovelling them up in the
same way. A stream of water issuing from the trap
door, laved the debris thus thrown in, washing along the
lighter material. The particles of gold, or black metal-
lic sand containing gold dust, settled down between the
cradles and lodged at the bottom of the box, prevented
from drifting away by the cross piece at the end of each
set of cradles.

It was now and here that the mosquito plague began.
I need not describe at length this well-known pest.
In the daytime and in the night they were with us and
upon us. The mosquitoes were succeeded by a worse
plague still. About the beginning of August came the
black gnat, in myriads, especially on a cloudy day.
There was no denying them. The agony I experienced

38 TEE EYDEAULIC

during that month while poling up the Yukon, unable
to protect my face and neck, is simply indescribable.

We had engaged ourselves on our return from the
head of the gulch to one of the men who first offered
us work. Our shift was during the night, from seven
to six, with a pause at midnight of an hour for dinner
and a smoke. The work was not only hard, but trying,
from our having to stand in the ice-cold water, which
sometimes in the hole dug out reached our knees.

I should have mentioned that a man was employed
in moving up and down the line of boxes, to keep them
clear, throwing out what stopped the free flow of the
water. The work, as described, went on from Monday
till Saturday. On Sunday we rested, leaving the
owners of the claim to clear the boxes. We generally
smoked our pipes on the morning of this day on the
bank above, watching them get in their find. They
proceeded in this way. The cradles were carefully
removed from the box and wiped clean. A small
stream was then allowed to trickle in, which washed
the debris to the low end of the box. The cross piece
here prevented it moving further. The water being
stopped, a brush then separated the sand and pebbles,
and disclosed the larger particles of gold. These were
scooped up and deposited in a steel gold pan, kept
for the purpose. The finer sand was deposited in
another pan, and the gold separated from it by rolling
quicksilver in, to which the gold adhered. The mass
was then exposed to a certain heat, and the quick-
silver evaporated. The contents of the other pan
were further purified by passing a magnet amongst

GOLD-MINERS MANUAL. 39

them, which carried off the particles of metallic sand,
the gold being scarcely attracted. Our wages were paid
at the end of this operation, at the rate of $8., or 32s.,
a day, i.e. half an ounce of gold dust. I brought away
$275 in dust, but had heavy deductions for food and
cost of getting out, with occasional rests through want
of rain, and the consequent short supply of water in
the gulch stream. We carried on this work from
June 27 till August 18, when it became "necessary to
decide promptly as to whether I should remain for the
winter or go out. I had for the week previous to the
18th virtually decided on the latter course. As a
party of seven miners were starting immediately, I
decided to run down the creek with them. To my
regret, Wilfred and Tom resolved to winter. I had,
therefore, on arriving at the post, to look out for a
partner. A surly looking cowboy was the only choice,
and him I paid $10 for a share in his boat. I am
bound to say I found no reason to complain of him
throughout the arduous journey that was to follow.
Arduous, indeed ! far more so than coming in Copy of
Letter to the ' Field ' Newspaper.

There are a great number of gems and precious and
valuable stones found in river beds accompanying gold,
which are passed unnoticed from want of knowledge by
the average miner, and which would often enable him
to add considerably to his "harvest." A few pages
from a pamphlet published separately by the author
of 'Gems and how to know them/ are added in the
hope they may prove useful.

40 THE HYDRAULIC

SIMPLE EULES FOE THE DISCRIMINATION OF GEMS.

The following is intended as a ready method of dis-
criminating between different gems having the same
outward appearance, but differing essentially in many
particulars which constitute their market value.

As, in nature, they are rarely found in a condition
" to classify ~by inspection of their crystallisation" other
proofs must be sought before deciding their value.

In many instances the same crystalline form, or the
same colour, is found in totally different stones, while
in others differing colours render it difficult to recognise
the identity of essentially similar stones. We must
therefore get the assistance of other factors before pro-
nouncing judgment.

Of these, the most important sources of recognition
are specific gravity and hardness.

Specific gravity means the density or proposition of
weight to volume of a substance, and is a characteristic
of all substances; while the varying hardness is dis-
covered by a simple rule of thumb, easily obtained by
practice.

Presuming that the reader is acquainted with the
crystalline forms, such as the cube, the octohedron, &c.,
and their various modifications the cube having six
faces square ; the octohedron eight sides, equal-sided
triangles ; the dodecahedron twelve-sided diamond-
shaped rhomboids ; the tetrahedron four sides, each
triangular ; the. rhombohedron six sides, each rhombic ;

GOLD-MINERS MANUAL. 41

the prism, any column with three or more sides, which
when placed on its base may stand straight or oblique,
terminating abruptly with a flat face, or coming off to
a point, blunt or sharp, like a pyramid he will be,
able, if fortunate in finding perfect specimens, to recog-
nise the substance by simple inspection, combined with
colour.

Many minerals break, when sharply struck with a
hammer, in certain definite directions the planes of
their crystallisation or " cleavage " but if irregularly,
they exhibit what is called "fracture" usually con-
choidal.

Some minerals have a brilliant lustre like that of
metals, while others are glassy, silky, waxy or resiny
others are dull and quite destitute of lustre. The
lustre of a diamond is called adamantine.

Some minerals are colourless, white, black or any
colour, either dull or brilliant, and the same mineral
may have a variety of tints or colours. Some in mass
having distinct colour, when scratched, give a powder
altogether different from the mass : in other words, the
" streak," as it is called, may correspond with, or differ
altogether from, the mineral operated on e.g. the
sapphire has a blue colour but a colourless streak. In
some cases the streak is metallic. Tinstone (oxide of
tin) gives a whitish-grey streak, which at once distin-
guishes it from minerals having the same outward
appearance ; and an acquaintance with this fact would
have saved many prospectors from disappointment, as
hundreds of samples absolutely free from tin have been
sent to England under the impression that they were

42 TEE EYDEAULIC

that valuable mineral instead of tungstate of iron, &c.
The colour and transparency of a gem are best seen by
immersing it in water, half-an-inch below the surface.
Specific gravity coupled with hardness is the most
reliable test.

The rule for finding the specific gravity is to deduct
"weight in water' 1 from the "weight in air" and
divide the " weight in air " by the difference, e.g. :

Quartz weighing 1398 grains in air

862 water

536)1398(2-6

which is its specific gravity.

For hardness a scale has been adopted, of which the
following is a whimsical " memoria technica " and
which, though not accurate in the consonant denoting
the mineral, still is sufficiently suggestive to recall the
desired symbol :

Tall Gipsy Girl Flew Up Fells Queer

Talc Gypsum Calcspar Fluorspar Apatite Felspar Quartz
123 4567

To Go Die !

Topaz Corundum Diamond

8 9 10,

The first four may be easily arrived at by testing
with a steel knife ; the next two with difficulty ; but
7, 8, 9, 10 refuse to yield to steel, and it is therefore
necessary to be provided with specimens of quartz,
topaz, corundum (sapphire) and diamond, with sharp
edges, to make the test.

GOLD-MINERS MANUAL.

The diamond is the hardest substance known, while
the topaz is cut by the sapphire, and quartz by the
topaz.

No valuable gem is softer than quartz, or has a
lower specific gravity, except opal, which is 2 2.

No mineral which scratches quartz has the curved
edges of the diamond. Therefore any mineral which
scratches quartz, and has curved edges, is a diamond.

A great number of stones identical in composition
occur of various colours white, yellow, brown, black,
red, violet, green, &c. In the following table of specific
gravity and hardness the different stones are arranged
under the different colours, and the characteristics of
those which occur under more than one head are not
repeated, but referred back.*

WHITE STONES.

Diamond
Sapphire
Topaz ..
Quartz . .
Zircon ..

Sp. Gr.
3-5
4

3-5
2-6
4-7

Hardness.
10
9
8
7
7-5

YELLOW STONES.

Sp. Gr.

Hardness.

Diamond

Sapphire
Topaz ..
Chrysoberyl .
Tourmaline .

3-7
3-2

8-5
7-5

Beryl (emerald
Quartz ..

)

2-73

7-5

* In some instances these figures represent the average, and stoi
may vary two or three decimals.

TEE HTDEAULIO

BROWN AND FLAME-COLOTJRED STONES.

Sp. Gr. Hardness.

Diamond
Zircon (hyacinth)
Garnet \
Essonite/
Tourmaline . .

4 6-5 to 7-5
3-5 6-5 to 7'5

BED AND KosE-CoLOUBED STONES.

Sp. Gr.

Diamond
Deep-red Garnet
Sapphire
Spinel Euby ..
Topaz

Tourmaline . .
Zircon ..

3-5

BLUE STONES.

Diamond
Sapphire
Disthene (cyanite)

Topaz

Tourmaline

Beryl

Dichorite (water-sapphire) . .
Turquoise

Sp. Gr. Hardness.

3-3 5 to 7

2-6 7 to 7'5
2-8 to 3 5 to 6

VIOLET STONES.

Sapphire

Tourmaline

Quartz (amethyst) . , . ,

Sp. Gr. Hardness.

GOLD-MINERS MANUAL. 45

GREEN STONES.

Sp. Gr. Hardness.
Diamond
Sapphire

Chrysolite . ... 3-3 6' 5 to 7

Tourmaline
Emerald }
Aquamarine/
Chrysoprase (see Quartz)

CHATOYANT STONES
are easily recognised by their play of colour.

BLACK STONES.

Sp. Gr. Hardness,

Diamond

Tourmaline : this stone when broken, looks a little
like black resin.

The diamond, sapphire, garnet, tin ore, gold and
platinum are common in river sands.

Platinum is easily recognised by its great weight
(the specific gravity being fully as high as gold) and by
its steel-grey colour. It is usually in flattened pieces,
rather larger than a pin's head.

Tin ore (oxide of tin) has a peculiar resiny look, a
specific gravity of 6 * 8 to 7, and hardness 6 to 7. If
powdered, and mixed with twice its weight of cyanide
of potassium and one-fourth its weight of charcoal in
a crucible, and 50 or 60 grains of cyanide of potassium

46 TEE ETDEAULIC GOLD-MINERS MANUAL.

sprinkled on the top, the heat of a kitchen fire is
sufficient to produce a globule of tin.

All polished gems become more or less electric by
rubbing on cloth, but the diamond in its natural state
and the topaz become very highly electric ; and the
topaz retains its electricity for so long a time that it
is a very useful test by which to recognise it. It
is also pyro-electric that is, becomes electric on the
application of heat by the blow-pipe, or even by a
candle. This distinguishes it from the diamond, which
has nearly the same specific gravity.

Tourmaline, too, becomes polar-lj electric by heat,
attracting and repelling on the opposite sides.

Zircon, which is used in watchmaking as " rough
diamond," is non-electric, as is also the sapphire. So
that these five principal stones can be easily dis-
tinguished.

The diamond gives a peculiar sound when two are
tapped together, which is easily recognised by those
who are in the habit of handling them.

Quartz gives a peculiar smell when its pebbles are
rubbed together, called by school-boys "firestone smell"
All the above characteristics will, if carefully noted,
enable a novice to distinguish between the different
gems, if found in a rough state or imperfectly crystal-
lised form.

LONDON : FEINTED BT WILLIAM CLOWES AND SONS, LIMITED,
STAMFOBD STKEET AND CHABING CBOSS.

APPENDIX.

IT is a most important part of the stamp battery that
the screens used in the mortar boxes are of the very
best make and quality. In this connection, mention
may be made of the well-known "Agate Steel" Stamp
Battery Screening, specially prepared for gold mining by
N. Greening and Sons, Limited, Warrington, England.
Nothing can surpass their screens for regularity of mesh,
and the heavy qualities are remarkably substantial and
enduring. The firm in question make all descriptions of
battery screening, ranging from 100 holes per square
inch up to 40,000 holes per square inch.

Specialities >

"AGATE STEEL
SIEVING

PERFORATED PLATE

Specially

Manufactured and Prepare
pop all

Wire Screening

AND

Perforated Plates

IN ALL

Metals AND Mesnes

PATENT STEEL BELTING

POP

ELEVATORS AND CONVEYOR

Screens. Ritiflies.Sievess

N. GREENING & SONS LL D

WIRE MANUFACTURERS
& METAL PERFORATORS

WARRIN GTON, ENGLAND

WINERS' POCKET BOOK

A REFERENCE BOOK

FOR

MINERS, MINE SUEVEYOKS, GEOLOGISTS, MINERALOGISTS,

MILLMEN, ASSAYERS, METALLUKGISTS, AND METAL

MERCHANTS ALL OVER THE WORLD.

C. G. WARNFORD LOCK,

Author of * Practical Gold Mining? * Mining and Ore Dressing Machinery J

CONTENTS.

Motive Power.

Dams and Reservoirs.

Transmitting Power.

Weights and Measures.

Prospecting.

Boring.

Drilling.

Blasting.

Explosives.

Shaft Sinking.

Pumping.

Ventilating.

Lighting.

Coal Cutting.

Hauling and Hoisting.

Water Softening.

Stamp Batteries.

Crushing Bolls.

Jordan's Centrifugal Process.

River Mining.

Ore Dressing.

Gold, Silver, Copper Smelting.

Treatment of Ores.

Coal Cleaning.

Mine Surveying.

British Rocks.

Geological Maps.

Mineral Veins.

Mining Methods*

Coal Seams.

Minerals.

Precious Stones.

Metals and Metallic Ores.

Metalliferous Minerals.

Assaying.

Glossary.

List of Useful Books.

Index, &c. &c. &c.

E. & F. N. SPON, Ltd., 125 Strand, London, W.C.

J.U

WJtll^M BUKJK.UWHU

LOAN DEPT.

This book is due on the last date stamped below, or

on the date to which renewed.
Renewed books are subject to immediate recall.

K bU.

ERS.

23Mar

APR 10

JAN 2 2 2001

ORMERS.
.ND

DRILLS.

^^or-xtya- *rg X bf . TT^gxrx, 26^ Ibs.

Fires 25 Abel's "high tension fuses in parallel.
40 low series.

PRICES AND LISTS FREE ON APPLICATION.

SIEMENS BROTHERS & GO.

LIMITED,

ELECTRICAL ENGINEERS.

CONTRACTORS /

/ /'*^

Electric Xiobtin^ ines,
Electric tlransrr/}^ >f power,

WINDINr PUMPS,

r /^3/^ ./TIVES, FANS,
DP' .NG MACHINES.

>ON OFFICES:

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