COAL MINING. 331 
The money invested for such purposes will surely find its way back into 
the pocket of the owner of the mines. The hoisting arrangements of 
slope mines differ somewhat from those of shaft mines; in the former 
the track is nearly always single, and only one rope is needed, while in 
shafts the hoist is double. At many slopes a chain is often preferred to 
a wire rope, but the rope is preferable. 
The pit head-frame of shaft mines is made 35 to 40 feet in height ; 
the upper landing, where the coal is delivered, is 22 to 25 feet above 
the mouth of the pit, and two screens are used in sorting the coal into 
lump, nut and pea, as it goes from the tipple into the hoppers below. 
All mines have water in them. In many drift mines, particularly 
in those in which the workings extend to the verge of the strata, the 
water is discharged by gravitation. In slopes and shafts, natural drain- 
age is impossible, and the waters of the mine must be pumped or lifted 
out by steam power. A number of first class coal pumps are in use in 
coal mines, Cooper’s and Blake’s being generally preferred to others. 
The size of the pump is governed by the amount of water. Some 
mines discharge much more water than others, and the mines of some 
districts are wetter than those of others. Inthe Mahoning Valley more 
water is met with than elsewhere in the State; this is due to the open 
character of the coal—the joints of which serve as reservoirs. A 
favorite pump in this valley, and one still largely in use, is the Buffalo, 
which has wooden pitmen, which run down the side of the slope. One 
of the first things necessary after coal has been struck in a slope or 
shaft mine, is to sink a water lodgme=t or sump. ‘This is cut in the 
floor of the coal, and is sunk to a depth of 8 or 10 feet, and made of 
sufficient diameter to hold several hours’ supply of water. A number 
six steam pump of the Cameron, Cooper, or Blake manufacture will 
discharge 500 gallons of water per minute, while 200 gallons per minute 
is a good flow ina mine. ‘The quantity of water in mines varies greatly ; 
frequently ,two pumps are necessary, sometimes three, and in the Lead- 
ville shaft in the Mahoning Valley, six No. 6 steam Cameron pumps 
were unable to keep down the water, even while the shaft was going 
down. So great was the flow of water in this shaft that special pumps 
had to be manufactured expressly for the occasion, and a special shaft 
sunk along side of the main shaft in order to control the water. More 
than 3,000 gallons per minute were pumped out of the mine. The 
history of this shaft is so remarkable that in the description of the 
