square of the pump's diameter in inches; and again multiply by 2.046, dividing the product by 165,000, and the quotient will be the horse-power required.

Ex.-Required the power necessary to overcome the resistance and friction of a lift 20 inches diameter, 400 feet high, the water being delivered at the pump-head with a velocity of 100 feet per miunte.

400 x 100 × 202 × 2.046
165,000

198 horse-power.

To find the quantity and weight of water in a lift of pumps, or pressure column:

Multiply the area of the pump or pressure column by the height of the column in inches, divide the product by 277-27, and the quotient will be the number of gallons; then multiply by 10, which will give the weight in pounds.

Ex.-Required the number of gallons and weight contained in a column 20 inches diameter, and 400 feet high.

of

202 x 7854 314·16 = area pump. Then (314 16 × 400 × 12 = 1,507,968) 277·27 = 5,438 galls. x 10 = 54,380 lbs. as weight of column.

To find the quantity and weight of water which can be delivered by a given plunger or bucket at each stroke :

Ascertain the area of the plunger or bucket, multiply by the length of the stroke in inches, divide by 277 27, the quotient will give the number of gallons discharged per stroke; multiply by 10, and the product is the weight of water in pounds delivered.

Ex.-Required the number of gallons of water discharged by a 20-inch plunger, 9 feet stroke, and weight of the same.

202 x 7854 = 314-16, area of plunger; Then 314-16 × (9 feet x 12 in.) 108 277-27 = 122.3 gallons per stroke: 122.3 x 10 = 1223 lbs. delivered per stroke.

Approximative Rules for determining the weight and quantity of water contained in pipes.

1. Square the diameter of the pump in inches, and multiply by length in feet; the product, multiplied by 34, will be the weight in pounds of water contained in the column, nearly.

2. Multiply the square of the diameter, in inches, by the length also in inches, and by 00283; the product will be the contents in gallons, nearly.

TABLE SHOWING THE WEIGHT OF WATER PER LINEAL FOOT, AND PER FATHOM, IN PUMPS FROM 4 INCHES TO 33 INCHES DIAMETER.

14.18

36.7

111

103.86

44.95

269.7

276.11

119.50

717.00

530.93

229-77

1378.62

15.90

6.88

41.2 11

108.43

46.92

281.5

19 283.53

122.70

736.20

26

541-19

234.21

1405.26

NOTE.-Two Flanges are generally reckoned to be equal to one foot of pump.

238.0

269.0

300.5

247.9

STEAM MACHINERY.

THE history of the steam-engine as applied to mining is comparatively brief. Savery, about the year 1696, was probably the first who employed steam power to raising water. In Savery's engine a vacuum was formed in the receiver by the condensation of steam; water was then forced into it by the pressure of the atmosphere, and elevated to any required height by the direct action of steam. Several of these engines were erected in different parts of England, and some idea of the inventor's opinion of them may be gathered from the following statement:"I will raise your water 500 or 1,000 feet high, could you find us a way to procure strength enough for such an immense weight as a pillar of water that height; but my engine at 60, 70, or 80 feet, raises a full bore of water with much ease." This inventor introduced the term horse-power. Savery's engine was ultimately superseded by Newcomen's atmospheric engine, introduced about the year 1705. The construction of this machine differed widely from that of Savery's arrangement, inasmuch as the steam exerted no direct action upon the surface of the water to be elevated, but was employed as the means of forming a speedy vacuum beneath a piston attached to one end of a lever, the pump rod being in connexion with the other extremity. In this way atmospheric pres sure performed the principal duty, whilst steam was merely used as a means of removing the air from beneath the piston. To this inventor belongs the credit of introducing the beam or balance lever, and the method of condensing steam and forming a vacuum by immediate contact with cold water.

The various cocks and valves were opened and closed by hand, until a boy, named Humphrey Potter, ingeniously connected them with the beam by means of strings and catches. This contrivance not only gave greater regularity to the movements of the engine,

NOTE.-Two Flanges are generally reckoned to be equal to one foot of pump.