Beautiful rare stock certificate from the Potosi Mining and Smelting Company
issued in 1876. This historic document has an
ornate border around it with a vignette of a wagon next to a millsite. This item has the signatures of the Company’s President and Secretary. Fine condition. Issued to Jacob Hardy.
Prospectus, Potosi Mining and Smelting Company, Cerro Gordo Mining District, Inyo County (San Francisco, 1874).
GENTLEMEN :—The undersigned, Trustees of the
Potosi Mi~ningand Smelting Company, beg to invite
your attention to ourmining enterprise in Cerro Gordo
Mining District, Inyo County, ‘Cal. We feel confident
that you will readily recognize its meritorious character, and that a careful, consideration of the advantages
which it offers will strongly incline you to invest the
moderate amount of capital required.
The argentiferous-galena mines of Cerro Gordo
have been worked six years, with but little outsideaid,
on a contracted scale, almost without machinery, and
under the burden of an expensive transportation of
250 miles to Los Angeles; yet in spite of all obstacles,
these mines have paid in-that time a net profit of one
million eight hundred thousand dollars, (~i,8oo,ooo)
and have furnished a large proportion of the bullion
refined at Selby’s works, San Franciso
There is on the western slope of the Cerro Gordo
Mountain, within a lineal distance of four-fifths of a
mile, the most remarkable concentration of parallel
veins of rich ores of silver and lead that can be found
in this country. Between what is called the lower
town of Cerro Gordo and the summit of the mouri.
tam, some 4,400 feet, there are known to exist not less
than ten parallel veins of ore, ranging in value from
$25 to $200 per ton in silver, and carrying from 25 to
85 percent. of lead. - The largest vein at the surface-._.
the Buena Vista—is near the summit, and has the ex.
traordinary width of one hundred (ioo) feet. DesCend.
ing towards the town, the next vein is the Union Mine,
which has furnished a large proportion ofthe ore pro.
duct ofthe district. It has been worked to a depth of
about 700 feet, the deposits becoming wider and richer
as the depth increases. The present width of ore is
forty feet. This mine has been bonded to foreign
capitalists, pending a lawsuit as~to ownership, for
The San Felipe Mine is in close proximity to the
UniOn. Next comes the Omega, with a splendid body
of.Ore thirty feet wide. This vein has widened from
four feet at the leve1~ofthe Omega Tunnel, to thirty
feet~a hundred and fifty feet below, and from the Sur
face of the mine 310 feet Next is the Santa Maria,
witha vein ‘31 100 feetwide! Then follow the Jefferson,
Cannan, Guadaloupe, Guythas, First and Second Lead
Mines, San Bernto, Alpha, and Ignacio The last
named is a valuable silver mine, which, with very itn
perfect working, has yielded a large amount of ore,
averaging $i8o per ton Some of it carries $x,Soo to
the ton. The enterprise in which we are engaged, and
to which your attention is specially directed, is
THE POTOSI TUNNEL.
The mouth of which is 4,400 feet distant from the
above mentioned Buena Vista Lode, at the summit of
the mountain. It will cut the entire series of veins on
the slope at an angle of 64 deg., and a depth of from
~oo feet at the mines nearest the entrance, to 2,140
feet below the surface of the Buena Vista Mine.
Thus in the short space •f 4,400 lineal feet, this
tunnel will intersect ten known rich mines, at an average depth of say 850 feet. This tunnel will greatly
facilitate the working of all these mines. The slope of
•the mountain above the tunnel entrance is quite steep,
and renders transportation expensive. The grade below the tunnel is easy. In the matter of drainage, the
extraction of ore, and the general interior working of
a mine, the advantages of a tunnel are obvious and
generally admitted. Several of Ilie t5rinciAal veins intersected by tills tunnel óelong to tile Potosi A/lining and
Smelling Comj5any. The mammoth Buena Vista, the
First and Second lead mines, the extension of the San
BenitO, and the Alpha, are the Company’s property,
and arrangements have been made to acquire the Ignacio Silver Mine and other valuable mines on the line of
The Potosi Tunnel is so located as largely to control the mining operations of the distrIct. It commands all the ground along its line. All blind lodes
discovered in its progress (and there is every reason to
anticipate such discoveries) will belong to this Corn-
pariy. No rival enterprise, even if it had a right to
the ground, which is legally preoccupied by us, could
gain an additional depth of 500 feet without running
a mile through barren ground.
ORES, THEIR CHARACTER AND QUALITY.
The ores from these mines are a mixture of lead and
silver, mostly suiphurets, with some suiphates, and a
large amount of carbonates. The ores from the silver
mines consist of rich sulphurets and chlorides, with a
little native silver. The silver ores average $i8o per
This is done at the mines, in thirty-inch cupola furnaces. Fire-clay of excellent quality is abundant at
the mouth of the tunnel. It is mixed with pulverized
quartz, moulded, sun-dried, and is then ready for use.
The charges of ore, consisting of the suiphurets and
carbonates oflead and silver, with a due proportion of
ferruginous ore and argentiferous quartz, melt like wax
in the furnace. An average run for twenty-four hours
IS 240 bars of bullion. So perfect is the process that a
furnace has here been run for a hundredconsecutive days
withoutstop. The amount of fuel required to smelt a
ton of this ore is the smallest known to th~practice
ofthe metallurgist. Twenty bushels of charcoal to the
ton of ore is the regular allowance at Cerro Gordo,
while in the best managed European furnaces the quantity is nearly or quite double. (See Raymond’s keport
On the Mines in the U. S., 1873.) Charcoal costs at
Cerro Gordo twenty-eight cents per bushel by the
The cost of bullion transportation has heretofore
been high, and is now about $~per ton from Cerro
Gordo to San Francisco. The value of the lead in
the bullion covers this, together with the cost of mining and smelting, leaving the value of the silver as net
profit. The bullion carries about 90 ounces of silver
to the ton.
THE PROJECTED RAILROAD
From Los Angeles to Cerro Gordo, will, when in
operation, reduce the freight on bullion at least $30
per ton, adding that mu~chadditional pro~to the mines.
There is every reason to expect that this road will be
PRESENT STATE OF TUNNEL.
It is already in nearly 500 feet and is within 400
feet of the Ignacio Silver mine referred to above. The
company have made arrangements to immediately put
on a BUR~LEIGH DRILL of the largest size, capable of
making ten feet per day, and of completing the tunnel
in 400 working days. The cost ~ofthe drill and acçompanying machinery will be about $i~,ooo. The
tunnel is to be nine feet wide and eight high, and will
have a double track.
There is at the present time an abundance of water
for all necessary purposes flowing from the tunnel, thus
saving the purchase of water at four cents a gallon
About 1,000 feetfrom the mouth the tunnel will pierce
a heavy trap dyke, which by its impermeability dams
the entire flow of water in the mountain above. When
this trap is perforated there will be sufficient water to
supply a population equal to that of the town of Cerro
Gordo. It will undoubtedly afford the Company a
considerable revenue. The Company have located ten
acres of ground adjacent to the tunnel entrance, affording ample space for dumps, furnaces, buildings,~etc.
In twelve months from the time the Burleigh Drill
is put in operation, the Company expect to be able to
extract from their own mines and to reduce daily xoo
Tons Galena Ore anSI Twenty Tons of Silver Ore, of
the value of $8,ooo. Deduct cost of mining, hauling,
and smelting same, $3,800, leaves a margin of $4,200
per day, and per month of twenty-six days $109,200.
Within two years this result could be easily doubled,
and thereafter still further increased.
TUE REVENUE from the transportation through the
tunnel of the ore of the other mines, will amount to a
very large sum. It may be estimated to reach, by the
time the tunnel is completed, a quarter of a million of
dollars per annum.
Enough has been said to show clearly that the enterprise of this Company is one of imposing dimensions,
practical, and comparatively inexpensive. The total
cost of completing the tunnel will not exceed $ioo,ooo.
This estimate does not take into account the self-supj5orting character of the enterprise, as soon as the tunnel reaches the first vein. .11 is already in uJ’on a~romising- vein of ore. The Trustees believe that, owing to
this self-supporting feature of the work, an amount not
exceeding $30,000 will be found sufficient.
The CAPITAL STOCK of the Company IS $5,000,000.
There are 50,000 shares of $ioo each.
To the tunnel and tunnel property is in the, Company,
and is undisputed
Ten thousand shares of the Capital Stock are reserved to furnish a WORKING CAPITAL.
The officers of the Company are
J AMES A. PRITCHARD President and Treasurer.
J. HARDY Secretary.
Office of the President, Rooms x and 2, Academy
Secretary’s Office, 408 California St., San Francisco,
JAMES A. PRITCHARD,
Trustees Potosi Mining and Smelting Comj5any
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