Silver and Gold: an Account of the Mining and Metallurgical Industry of the United States: With Reference Chiefly to the Precious MetalsJ.B. Ford, 1873 - 566 من الصفحات |
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الصفحة 35
... engine attached to a grip- pulley . The function of the grip - pulleys is to hold the rope so as to prevent its slipping in the groove . In general , the difference in altitude between the mill and the mine is sufficient to obtain by ...
... engine attached to a grip- pulley . The function of the grip - pulleys is to hold the rope so as to prevent its slipping in the groove . In general , the difference in altitude between the mill and the mine is sufficient to obtain by ...
الصفحة 36
... engine at one end by means of the grip - pulley ; in the first case , often no extra power will be needed , the gravity of the descending loads being sufficient to keep the rope in motion . Similar inventions have been made before , and ...
... engine at one end by means of the grip - pulley ; in the first case , often no extra power will be needed , the gravity of the descending loads being sufficient to keep the rope in motion . Similar inventions have been made before , and ...
الصفحة 43
... engines attached to the drill with delicate parts and nice adjustments to be destroyed by the concus- sion and recoil of the blow . The construction is such that the connec- tions between the drill and the driving machinery cease at the ...
... engines attached to the drill with delicate parts and nice adjustments to be destroyed by the concus- sion and recoil of the blow . The construction is such that the connec- tions between the drill and the driving machinery cease at the ...
الصفحة 44
... engine is at the surface , power can be taken from it to operate in the deepest and most extensive mine . Where a high fall of water can be obtained , a small wheel attached to the drill gives a very convenient power . This machine has ...
... engine is at the surface , power can be taken from it to operate in the deepest and most extensive mine . Where a high fall of water can be obtained , a small wheel attached to the drill gives a very convenient power . This machine has ...
الصفحة 62
... engine of 25 horse - power . The Knox mine , one - half mile from the Heslep , is 1,200 feet in length , with a vein 10 to 20 inches in width . It is owned by Preston & Co. They have hoisting - works run by a 30 horse - power engine ...
... engine of 25 horse - power . The Knox mine , one - half mile from the Heslep , is 1,200 feet in length , with a vein 10 to 20 inches in width . It is owned by Preston & Co. They have hoisting - works run by a 30 horse - power engine ...
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