G. Thomas (George Thomas) Ingham.

Digging gold among the Rockies; or, Exciting adventures of wild camp life in Leadville, Black Hills and the Gunnison country online

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and northern extremities it is frequently broken
and lost (invariably so at the intersection of the

II2 $4,000 ORE.

principal rivers), making its appearance again at
a distance, frequently in the form of a solid wall
of quartz, on the summits of the hills on the line
of its strike. These croppings are visible for
many miles. It varies greatly in thickness. Fre-
quently, from a series of parallel, narrow veins, it
becomes concentrated in one strong, permanent,
true fissure vein, of from fourteen to eighteen feet

Usually most all true veins increase in richness
with depth ; and it is the exception, rather than
the rule, that the reverse is the case ; yet the
Comstock Lode, which has been explored from
twenty-two hundred to three thousand feet in
depth, and from which about four hundred millions
in bullion have been extracted, was the richest
near the surface. The first forty tons of ore taken
from the Ophir Mine, on the lode, was "packed"
on mules, and sent across the Sierra Nevadas to
San Francisco, and yielded one hundred and sixty
thousand dollars, or an average of four thousand
dollars per ton. Yet no body of ore, of conse-
quence, has since been found approaching this
value per ton. It may readily be imagined that
the discovery of four-thousand-dollar ore created
an intense excitement in California.

In some of the mines, the ore now averages
from forty to one hundred dollars per ton. The
great lode varies in width from fifty to one hundred
and fifty feet, and its length is about four miles.


Many theories exist as to the formation of such
immense fissures, and as to the causes which filled
them with quartz and ore, and there is a great
diversity of opinion among 1 scientific men in regard
to it.

The theory probably most commonly accepted
by practical miners is, that of filling from below,
or the pushing up of vein matter from the bowels
of the earth, in a liquid state, filling the fissures or
cracks in the earth's crust, thus forming these
great bodies of ore.

We give below an extract from an address by
Mr. Adolph Sutro, the projector and chief engineer

The Sutro Tunnel.

of the celebrated Sutro Tunnel, which pierces the
Comstock Lode at a depth of seventeen hundred
feet from the surface, and is over four miles in
length, being one of the most remarkable and
skillful engineering feats ever accomplished in the
United States, and which is of incalculable value
to the Comstock Mines as a drainage level and
means of ventilation.

Mr. Sutro may therefore be considered high
authority on this subject, and his views are enti-
tled to great consideration. The address was
delivered before the New York Bullion Club,
November 6th, 1879.

"The Comstock Lode appears on the surface of
a range of hills called the Washoe Mountains,


lying east of the Sierra Nevadas and running
parallel therewith. The lode occurs mainly at the
contact of two kinds of rock, and is therefore in
fact, to a large extent, a contact vein, though in
other parts, as at the north and south ends, it is
surrounded by the same kinds of country rock.
The central portion of this mountain range is
formed by Mount Davidson, a mountain rising to
the height of about seven thousand eight hundred
feet, and which consists of syenite ; this is probably
the oldest formation of that neighborhood.

" Immediately east, and in fact west of Mount
Davidson, we find greenstone or porphyry, of
which great varieties exist, and which for con-
venience are called by the family name of prophy-
lite. Still further east we find the trachytic moun-
tain range.

"There have been various theories advanced as
to the origin of that lode, but there can be hardly a
doubt that it is a true fissure vein ; all evidence
tends to show that such is the fact.

Formation of the Fissure Comstock Lode.

" According to Baron Von Richtholfen (who is
probably one of the ablest geologists now living,
and who has made a careful examination of the
Comstock section of country, spending nearly two
years there), the syenite is the oldest formation,
the prophylite or greenstone coming next in order,
while the trachyte is the outburst which appeared


at the latest geological period. If we examine the
locality, we find, as already indicated, that the
Comstock Lode occurs mainly between the syenite
and porphyry. The probability is that when the
trachyte made its appearance, the upheaval was
so great that it uplifted a large portion of the

" The effect of this upheaval was, that a fissure
was formed at the plane of least resistance, that is,
at the point of contact between the two rocks
(the syenite and porphyry), large masses of country
rock from the hanging wall falling into the fissure,
forming what we now call * horses,' were the
cause of keeping the fissure open.

" Had it not been for the fact of these masses
falling into the fissure, it would in all probability
have closed up again. But in this manner there
was left an open channel down to an indefinite
depth, which gradually became filled, probably by
means of thermal agencies, or possibly by volatili-
zation, according to the different theories which
scientific men accept.

Filling of the Fissure.

" These masses or horses must have necessarily
fallen into the fissure from above ; and as a proof,
we have the fact that in the Comstock Lode, every
'horse* consists of greenstone, that being the
upper rock, the syenite being at the bottom, none
of it could have fallen into the lode. The open


spaces thus left in the fissure were gradually filled
and the horses became surrounded by quartz and
minerals, mainly silver ores carrying more or less
gold, which are sometimes accompanied by the
base metals.

" I listened with great attention to the lecture
of Professor Newburry, delivered last week, in
which he expressed the opinion, that the particular
fissure which he was describing had been filled in
with ore by the process of deposits from thermal

" It seems to me hardly probable that the Corn-
stock Lode was entirely filled in that way. It is
probable that different processes were at work at
different periods ; and it is very likely that a por-
tion of the vein matter which now fills that lode,
entered it by the process of volatilization.


" It seems difficult to imagine silver or gold in a
gaseous form ; but if you consider fora moment it
does not appear strange. We know that all the
substances of the entire globe exist in one of three
forms ; solid, liquid or gaseous ; while some sub-
stances are familiar to us in all three forms. Take
water for instance, we know it as a solid when it
is ice, we know it as a liquid ordinarily, and we
know it as a gas in the form of vapor. We know
all the metals in two of these forms ; as solids and
liquids when molten. We know some of the


metals in all three of the forms. In fact, in our
laboratories, we can convert many solids into

The Theory of Volatilization.

liquids by melting", and even into gases by volatili-

" Now, if we imagine the great laboratory of na-
ture down in the bowels of the earth, where all
the agencies probably exist which are necessary
for reducing these various minerals to a gaseous
state, the filling of fissure veins with metals does
not appear so difficult of explanation.

" We must try to realize that in the fact that in
that laboratory of nature, there may exist a pres-
sure of millions of millions of pounds to the square
inch, and that the steam which is there generated
may be heated to a white heat ; that is, hot enough
to melt iron or any other substance. If we can
imagine such a heat as that, we can readily perceive
how any substance might be volatilized; and if
to these two forces certain chemical agents are
added, the transformation will seem still more
probable. I doubt that a vein of the size of the
Cornstock could ever have entirely been filled by
deposits from water.

Downward Continuance of the Comstock;

" These theories may be correct or not, but we
do absolutely know that we have here a vein
which lies between Mount Davidson, the syenitic


mountain, and the prophylite adjoining it, extend-
ing for a distance of four miles, and reaching
downward as far as the miners have gone, and in
all probability further than mechanical means will
ever permit man to go. There are obstacles in
the way which will prevent exploration to an in-<

Great Depth of the Comstock Lode.

definite depth. As far as the lode itself is con-
cerned, we find it retains its general characteristics
at various depths, that it varies in width from fifty
to one hundred and fifty feet, that it consists of
solid quartz interspersed with particles of ore;
but that in many portions it is not sufficiently rich
in ore to pay largely for extracting.

" It seems that the ore of the Comstock Lode
often occurs in the form of pockets, or channels,
or chimneys, or, as we call them when we find a
great ore body, * Bonanzas/ It is strange that in
the vein itself a Bonanza hardly ever occurs.


" The lode descends on an incline eastwardly,
following the dip of Mount Davidson. In places the
pitch is greater than at others, but the average is
about forty-five degrees. The ore bodies seem to
occur outside and to the east of the vein ; they are
generally of lenticular form. It frequently hap-
pens that in sinking a shaft, or in running a drift,


no ore at all is found ; a drift may run right over
or under it, while the very next drift may show an
ore body of great width.

" This accounts for the great fluctuations which
have taken place in the prices of the stocks of
mining companies on the Comstock Lode.

" People who are not familiar with the situation
do not understand the reason for such fluctuations.
But what I have stated will explain one of the

" These ore bodies are not confined to any par-
ticular spot. The country to the east of the Com-
stock Lode may contain ore bodies to an almost
indefinite extent. If we imagine, which I firmly
believe, that the Comstock Lode continues down-
ward for miles, then it is possible that these ore
bodies may make their appearance at compara-
tively lesser depths, several thousand feet to the
eastward of the present workings. The disposi-
tion of these ore bodies is not governed by any
rule. It seems to be entirely arbitrary. We do
not know where they are until we stumble upon
them. The only way to look for them is to run
drifts all through the country, and then to cross-
cut from these every one hundred or two hundred

"Some men say that the Comstock Lode is
working out. This is nonsense. Several deposits
have been found which were of such immense
value as to astonish everybody. But these ' Bo-


nanzas' were limited in number, probably not
over a dozen altogether; and they were always
found in the manner I have described."

From the foregoing it will appear that the value
of any vein, when first discovered, is very uncer-
tain. It may be a veritable Bonanza, and it may
not be worth anything. The ore may improve in
richness with depth, and it frequently does im-
prove as sinking on the vein progresses, or it may
be the richest at the surface, or become exhausted

Even the great lodes like the Comstock, which
have yielded their hundreds of millions, are very
fickle and uncertain in showing up their treasures.

Carbonate Ores of Colorado.

Frequently they have long periods of unproduc-
tiveness, before they stumble upon the rich pockets
or shutes of ore which they may contain. There-
fore, it is very uncertain how much wealth the dis-
coverer of a lode may have found, and it may take
years to fully develop the mine and prove its real

Hence it is that quartz mining is usually carried
on by large capitalists, by means of great corpora-
tions, as the risk and expense is very great for
private enterprise. Yet there are many valuable
mines successfully operated by private companies
or by individuals.

There is another class of ore deposits to which


we should briefly refer under this head, though a
more extended description of them will be found
hereafter, in the Colorado portion of this book
We refer to the carbonate ores of Colorado.

These deposits, when discovered, were almost
new to the mining fraternity, and have astonished
the world in their magnitude and in their peculiar
formation and richness in production. They can
hardly be called veins, but are vast deposits, lying
in nearly a horizontal position, like a coal measure.
They have been called contact veins, because
lying between the contact of limestone covered
by porphyry ; but they were so different from the
contact deposits of previous history in mining,
that miners were some time in learning their true
nature and extent. They are deposits of silver
ore, mixed with carbonate of lead and iron, lying
on a foot- wall or bed of limestone, and covered by
porphyry, varying in thickness from a trace to
thirty or forty feet of ore even seventy feet is
claimed to have been found of solid ore. They
lie in a horizontal position, in places but a few de-
grees from level, following the waves and depres-
sions of the limestone foot-wall, and covering
many square miles in extent, not unlike a coal
basin. The ore bodies vary as greatly in richness
as in the extent and thickness of the vein matter,
and mill, by smelting in furnaces, from ten to one
thousand dollars per ton. Even greater richness
has been found, but the average is generally from


fifty to one hundred dollars per ton. We will
refer to this subject again later in the work.

The First Quartz-mill

was built in California, at Grass Valley, Nevada
County, in 1851, where quartz mining has been
successfully carried on ever since. It was not
unlike the stamp-mills of to-day, but, of course,
imperfect, and has been greatly improved.

The stamp-mill is the process used on all ores
of gold and silver which are free milling ores ;
that is, ores not requiring to be smelted in a fur-
nace, or roasted, to extract the minerals they con-
tain. Some ores are of such a refractory nature
that it is impossible to extract their contents by
this process. Such ores usually contain a mixture
of sulphur, lead or copper, or all, in addition to the
precious metals, in such quantities as to prevent
their being amalgamated with quicksilver, in ,the
ordinary stamp-mill, and require smelting.

The Stamp-null.

All stamp-mills are built upon the principle of
crushing the ores to a fine paste or pulp, and thus
loosening the metals from their matrix of quartz ;
they are amalgamated with quicksilver in sluices
or batteries with water, after the manner described

Stamp-mills are built with from five to one hun-
dred and twenty stamps each, according to the


Until within the past two or three years, the cost of wrought iron excluded
its use in very many important places. The price at present enables us to
make the frame for a Stamp mill of wrought iron, and successfully compete
.with the wooden frame in price, and make the battery very much better than
by the use of wood, especially as in most instances the timbers of which a bat-
tery frame is to be made, are cut from the forest and used almost immediately,
without the least seasoning. When such timbers are used, although put to-
gether by the most skilled workmen, they shrink and open at the joints.
Soon the whole structure becomes shaky; the nuts upon the bolts jar loose,
requiring constant attention. These defects are all overcome by the use of
wrought iron in the construction of the battery frame. This material being
slightly elastic, successfully prevents the transmission of the jar through the
frame, and by the use of washers of the same material the nuts will not jar
loose from the bolts.


The ore is fed through the opening in the top of the bonnet- casting; imme-
diately on falling upon the revolving disc-plate, it is carried outward by centri-
fugal force to the rings or rolls, and when pulverized fine enough, is ejected
through the screens to a circular trough conveying it to copper plates for
amalgamation, or run into tanks for settling. The machine is constructed
also for dry pulverizing ; it will pulverize about one-fourth less dry than wet.
The frame for the machine is made of southern pine timber, is mortised and
tenoned throughout and held by strong joint-bolts. Each machine is put to-
gether at the works, and finished, marked and taken down for shipment.
An automatic feeder is provided especially for this machine, that will feed
the ore continuously. A rock breaker is provided also which is particularly
adapted to breaking the ore to the proper size for this machine, which must
not be larger than one inch. This machine will pulverize wet, hard quartz
rock to a fineness that will pass through a 4o-mesh screen, one ton per hour,
and will pulverize dry to pass through a 6o-mesh screen, half to three-quar-
ters of a ton per hour.


capacity required. These stamps may be termed
shafts, or bars of iron, standing perpendicular,
weighing from six hundred to nine hundred
pounds each, their feet or lower ends shod with
steel, which drop into iron mortars or boxes, also
plated with steel. These stamps are raised by
means of " cams " or eccentrics, placed on a hori-
zontal shaft of iron about five inches in diameter,
which lifts them up from eight to eleven inches,
when they instantly drop into the shoe or
mortar with great force upon the ore placed

The ore, after being crushed in a rock-breaker
to the size of an egg, or smaller, is introduced into
the shoes, into which a stream of water is running,
and the stamps drop upon it at the rate of sixty
strokes per minute, for each stamp, crushing it
to a fine paste. In this state the ore passes off
through a screen and on to the sluices or blankets,
over copper plates or into pans, according to
the plan of the mill and according to the kind
of amalgamating apparatus used, which col-
lect the gold and silver. The mills are usually
"cleaned up" every week, and the amalgam re-
torted, as in hydraulic mining.

A good stamp-mill will crush nearly two tons of
ore to each stamp in twenty-four hours. They
are driven by both steam and water-power.

As the location of veins and placer claims, and
the laws and regulations governing their location,


are intimately associated with the subject of
mining, and as a knowledge of the subject is in-
dispensable to those seeking Government title to
mineral lands, in the next chapter will be found
the most important laws on that subject.

Before leaving the subject of stamp-mills and
pulverizers, the following explanation of the Phelps
" Little Giant " Stone and Ore-Crusher (of which
pictures are given on the opposite page) will be
of interest and profit :


A. Side Plates.
BB. False Crushing Plates.
' C. Wrought-Iron Side Bars.
DD. Set Screws and Plates.

F. Reciprocating Jaw.

G. Rock Shaft.
H. Toggle.

I. Liners, or backing, by means of which the Reciprocating Jaw is
adjusted to crush fine or coarse.

J. Main Shaft.
K. Eccentric Pitman.
L. Eccentric.
M. FlyWheel.
N. Spring.
O. Pedestal.

P. Bearing of Reciprocating Jaw. (Dust proof.)





The Size of a Legal Claim, etc.

IN the early days of gold mining in California,
and in other States and Territories, on lands
belonging to the United States, the mining
laws were very imperfect, and disputes about the
titles of claims were of constant occurrence.

It appears that upon the discovery of every new
gold field, that the miners met and organized what
was termed a " Mining District," fixing certain
boundaries for it, and adopting a code of laws and
regulations governing the size of claims within the
boundaries named. Therefore, each new district,
although generally following after previous codes,
was liable to have a set of laws quite different
from other localities, and entirely dependent on
the fancy of the miners who organized it. Ac-
cordingly, the size of a claim that miners could
hold varied greatly in different localities such
being the crude state of the laws in those days
and very naturally disputes about title were very

In the early days there were no courts conve-
nient to settle such disputes, and a class of miners
called "Jumpers/* taking advantage of this fact,

became very numerous. If a miner found a rich



vein or a lucky strike, he was not at all sure of
holding his claim unmolested from this lawless
class. If he left his claim for a short time, he
might return to find another in possession, who
would dispute his title if ever so good, and as
there was no authority at hand to expel such
intruders, except the law of physical force y men
frequently took the law into their own hands, and
generally the strongest party held the claim.

From this cause there was much wrangling, and
frequently bloodshed and murder were of common
occurrence. Jumping claims, if not so common
now as in those days, is still in vogue, and such
occurrences are common in all new mining re-
gions, though to a less extent than formerly, and
probably always will be. There can hardly be
any law or authority strong enough to entirely
protect the weak against the strong, when great
selfishness and lust for gold are the leading charac-
teristics of the community.

According to the revised statutes of the United
vStates, no vein or lode claim made subsequent to
May loth, 1872, can exceed in size a parallelo-
gram fifteen hundred feet long by six hundred
feet wide. But whether surface-ground of that
width can be taken, depends upon the local regu-
lations of State or Territorial laws in force in the
several mining districts. But no local regulations
of State or Territory can limit a vein or lode claim
to less than fifteen hundred feet in length along


the course thereof, whether the location be made
by one or more persons, and surface rights cannot
be limited to less than fifty feet in width, unless
adjoining claims previously located on each side
render such limitation necessary. The end lines
of all claims must be parallel to each other.

The Cost of a Government Patent.

The owner can follow his vein anywhere in all
its dips, spurs and angles, providing he does not
go outside of his end lines.

In Colorado, the Legislature passed an act, in
1874, that all locations made thereafter in the Ter-
ritory should carry with them surface-ground of
one hundred and fifty feet on each side of the
centre of the vein, or in other words, could not
exceed in size a parallelogram three hundred feet
by fifteen hundred feet, except in the four counties
of Boulder, Gilpin, Clear Creek and Park, where
seventy-five feet on either side of the vein should
be the rule, making a legal claim in these four
counties of half the width above given. The law,
however, does not interfere with lodes discovered
prior to their adoption.

Previous to the enactment of this law, claims
had been of various sizes at different periods. At
one time, the discoverer of a lode could hold but
two hundred feet on the vein, and subsequent
locators but one hundred feet on the same vein.
Afterward it was chang-ed to fourteen hundred


feet for the discoverer, and for a short time it was
enacted that the discoverer could hold three thou-
sand feet on the lode.

After a Government patent has been issued for
a lode claim, the owner can hold it against all
comers or claimants, whether he works it steadily
or allows it to remain idle.

The cost of procuring a Government patent is
from one hundred and twenty-five to one hundred
and fifty dollars, when the location embraces one
thousand five hundred feet by one hundred and
fifty feet, and from twenty-five to thirty dollars
more than this, when fifteen hundred feet by three
hundred feet are included. The former class
embrace about five six-hundreths acres, and the
latter about ten thirty-three-hundredths acres,

Online LibraryG. Thomas (George Thomas) InghamDigging gold among the Rockies; or, Exciting adventures of wild camp life in Leadville, Black Hills and the Gunnison country → online text (page 6 of 27)