Enter a name, company, place or keywords to search across this item. Then click "Search" (or hit Enter).
Go to the Archive Home
Go to Thumbnail View of this Item
Go to Single Page View of this Item
Download the Page Image
Copy the Page Text to the Clipboard
Don't highlight the search terms on the Image
Show the Page Image
Show the Image Page Text
Reset View and Center Image
Zoom Out
Zoom In
Rotate Left
Rotate Right
Toggle Full Page View
Flip Image Horizontally
More Information About this Image
Get a Citation for Page or Image - Copy to the Clipboard
Go to the Previous Page (or Left Arrow key)
Go to the Next Page (or Right Arrow key)
Page: of 12
a ==
re
“
7
aL
COST OF PRODUCTION
"On account of the ideal mining and climatic conditions
in this district, the working-costs are exceptionally low for
such narrow veins, Total mining, milling and overhead cost
at the North Star Mine was $5.25 per ton in 1913; and while the
Empire Company refuse to divulge their production or costs, it
is generally conceded that their total cost isabout 50 cents
per ton lower than those of the North Star. These costs have
increased to over $7 a ton in 1918."
DEPTH OF MINES, AND DEVELOPMENT ON THE LOWER
LEVELS
In the discussion of the various mines, as given below,
matter quoted from other authorities presents the status of
operations in or about the year 1918,
"The North Star mine was worked to a depth of 2400
feet by an inclined shaft on the vein. A vertical shaft 1650
feet in depth was then sunk, which encountered the vein at a
point 4,000 feet on the dip of the vein. This vertical shaft was
connected with the old incline by. means of a 1600 foot arise.
The vertical shaft was then turned and continued down on the
vein until in July, 1915, it had reached a depth of 2300 feet
below the 4000 level, thus developing the vein to a total inclined
depth of 6300 feet below the outcrop."Recent developments in the North Star include the sinking
of the shaft to the 6800 foot level. The vein is over four feet
thick, of good milling ore, The bottom of the winze shows a
strong lege of good milling ore. During 1923-1924, under the
efficient management of Arthur Foote, cross-cuts and other
development have opened up a number of faces of good ore;
and the North Star of today holds ore enough in sight to assure
an output of a million a year for many years to come.
"The Empire shaft has reached a depth of 5000 feet on the
incline, and the vein is being developed by drifts at that depth.
The average dip of the vein above the 3400 level is about 30°
W., but below this level the vein rapidly steepens to a m2 ‘imum of 55° W.
"The Pennsylvania vein, which has an average dip of 40°
W., has been developed to a depth of only 2600 feet by the Pennsylvania inclined shaft, but has recently been opened by a crosscut from the 4600 level on the Empire shaft, giving a depth
of 3500 feet on this vein, or a vertical depth of 1900 feet. The
drifts from the lower levels of the North Star Mine have also
encountered the Pennsylvania vein at a vertical depth of about
2600 feet."
The Empire Mines Company today (1924) show a depth of
6200 feet, the same bing 390 feet below sea-level, the deepest
mine in California. The recent purchase of the Sultana Group
of mines adds two square miles to the pay-chute belt. Recent
development consists of cross-cuts connecting the bottom of the
2600-foot level Empire shaft with the 2400-level Pennsylvania
shaft.
The new Empire mine hoist is equipped with a 500-horsepower Elee Hoist with a 7000-pound foot lift. Five compressors
History of Nev
Published in
W.B. Lardner :
have a cubic-foot capacity of 7300 cubic feet urder 100 pounds
pressure. Forty-five miles of underground workings is now
the record. Car men under ground are helped on long hauls by
twenty-eight mules and two storage-battery electric locomotives,
The top plant consists of an eighty-stamp mill of 1750 pounds
California.
California, Twelve tons of drill steel are sharpened each
twenty-four hours in their modern machine shop.
Thirteen acres of park, containing nearly all California
trees and shrubs, form a background of beauty for this largest
and deepest, and most productive quartz mine in the State.
The Golden Center Mine was started in the center of Grass
Valley in 1916. They have developed ore bodies from the 500foot level to the 1000-foot level with good success, Their present equipment consists of a twenty-stamp mill fully equipped.
This, with a modern electric hoist, gives the company ample
machinery for all present purposes,
5 EET a ce