512 



MINmG INDUSTEY. 



In the pumping compartment there is an excellent ladder-way, with plat- 

 forms about 15 feet apart. The pump consists of an 8-inch plunger, placed 

 at 230 feet below the surface, with a 9-inch column of casii-iron pipe above 

 it, reaching to the surface. Below it is a lifting pump, reaching to the bot- 

 tom of the mine; the latter consisting of the working barrel, with the wind- 

 bore attached below, and sufficient length of pipe above to reach the cistern 

 of the standing pump, higher up, is suspended in the shaft by means of a 

 chain, that is attached to a stout screw, six or eight feet long. The screw 

 passes through a nut, which rests on a stout and firmly-secured timber. By 

 turning the screw, the whole of the sinking pump apparatus may be lowered 

 as the sinking of the shaft proceeds, and the wind-bore thus kept at the very 

 bottom, additional pipe being added at the top as it becomes necessary in the 

 progress of the work. 



The wind-bore is a very heavy casting, two inches thick, perforated with 

 inch holes, and is sufficiently strong to stand the blows of the rock that may 

 be thrown against it during blasting, without any protection. The working 

 of the pumps is effected by means of a pump-rod, operated in the usual way 

 by machinery at the surface. The rod is an 8-inch square timber, joined by 

 bringing the squared ends together, without splice or scarf, and secured by 

 straps of iron on two sides, eight feet long, four and a half inches wide, and 

 five-eighths of an inch thick, and bolted through with inch bolts. The en- 

 gine at the surface, used for pumping at this shaft and for hoisting at both 

 shafts, is a plain horizontal cylinder, 14 inches in diameter by 26 inches 

 stroke, supplied with steam by one flue boiler. 



Hoisting is done with a bucket. The winding apparatus is driven by 

 belting. As this method of hoisting is in general use in Colorado a some- 

 what detailed description of it here may serve as an example. The contriv- 

 ance is very simple, and, though not well adapted to deep shafts or heavy 

 work, it answers its purpose very well in shallow mines, and gives much 

 satisfaction. The general method of arrangement is indicated in Figs. 1 and 

 2, on Plate XXXL 



The drum, or spool, A, on which the rope is wound, is placed near the 

 mine shaft, so that the rope passes from it over a pulley, b, and thence down 

 the shaft. This spool, about 4 feet in diameter, is fixed on an iron shaft, c, 



