Dimensions of a barrel-Diameter of head, 17 in.; bung, 19 in.; length, 28 in.; volume, 7,680 cubic in.

Dimensions of billiard tables (Collender)-4 ft. by 8 ft.; 4 ft. 2 in. by 9 ft.; and 5 ft. by 10 ft. Size of room required respectively, 13 by 17; 14 by 18; 15 by 20.

Horse-stalls-Width, 3 ft. 10 in. to 4 ft., or else 5 ft. or over in width-nine feet long. Width should never be between 4 and 5 ft., as in that case the horse is liable to cast himself.

HORSE POWER OF STEAM ENGINES, ETC.

The unit of nominal power for steam engines, or the usual estimate of dynamical effect per minute of a horse, called by engineers a "horse power," is 33,000 pounds at a velocity of 1 foot per minute, or, the effect of a load of 200 pounds raised by a horse for 8 hours a day, at the rate of 21⁄2 miles per hour, or 150 pounds at the rate of 220 feet per minute.

RULE.-Multiply the area of the piston in square inches by the average force of the steam in pounds and by the velocity of the piston in feet per minute; divide the product by 33,000, and of the quotient equal the effective power.

ANOTHER RULE.-The diameter of the piston in inches, multiplied by itself, multiplied by the stroke in inches, multiplied by the revolutions per minute (not the strokes), multiplied by the mean effective (average pressure per square inch on piston), multiplied by .00000397, gives the gross or indicated horse power.

For the net effective horse power, deduct from the above about 14 for friction of the working parts.

The mean effective pressure can be accurately determined only by the aid of an indicator. When the indicator is not used, and in the calculation the boiler pressure is substituted for the mean effective pressure, deduct from the result obtained from 40 to 60 per cent. for loss by condensation and friction of steam pipes and passages, decrease of pressure in cylinder due to expansion, back pressure of exhaust, and friction of the working parts.

For engines from 20 to 60 horse power, an average of 50 per cent. may be deducted; for smaller engines, more.

The mean pressure in the cylinder when cutting off at
14 stroke equals boiler pressure multiplied by .597

66

66

66

66

66 .670

Best designed boilers, well set, with good draft and skillful firing, will evaporate from 7 to 10 lbs. of water per pound of first

class coal. The average result is from 30 to 60 per cent. below this.

In calculating horse power of Tubular or Flue boilers, con sider 15 square feet of heating surface equivalent to one nomina horse power.

One square foot of grate will consume on an average 12 lbs of coal per hour.

Steam engines, in economy, vary from 30 to 60 lbs. of fer water and from 2 to 7 lbs. of coal per hour per indicated H. P. HORSE POWER OF BELTING.

A simple rule for ascertaining transmitting power of belting without first computing speed per minute that it travels, is as follows: Multiply diameter of pulley in inches by its number of revolutions per minute, and this product by width of the belt in inches; divide the product by 3,300 for single belting, or by 2,100 for double belting, and the quotient will be the amount of horse power that can be safely transmitted.

Table for Single Leather, Four Ply Rubber and Four Ply Cotton Belting, Belts not Overloaded.

1 INCH WIDe, 800 feet PER MINUTE=1 Horse POWER.

Double leather, six-ply rubber or six-ply cotton belting will transmit 50 to 75 per cent. more power than is shown in this table. (One inch wide, 550 feet per minute=one horse power.)

A gallon of water (U. S. standard) weighs 8 pounds and contains 231 cubic inches. A cubic foot of water weighs 622 pounds, and contains 1,728 cubic inches or 71⁄2 gallons.

Doubling the diameter of a pipe increases its capacity four times. Friction of liquids in pipes increases as the square of the velocity.

The mean pressure of the atmosphere is usually estimated at 14.7 pounds per square inch, so that with a perfect vacuum it will sustain a column of mercury 29.9 inches or a column of water 33.9 feet high.

To find the pressure in pounds per square inch of a column of water, multiply the height of the column in feet by .434. Approximately we say that every foot elevation is equal to 2 pound pressure per square inch; this allows for ordinary fric

tion.

To find the diameter of a pump cylinder to move a given quantity of water per minute (100 feet of piston being the standard of speed), divide the number of gallons by 4, then extract the square root, and the product will be the diameter in inches of the pump cylinder.

To find quantity of water elevated in one minute running at 100 feet of piston speed per minute: Square the diameter of the water cylinder in inches and multiply by 4. Example: Capacity of a 5-inch cylinder is desired. The square of the diameter (5 inches) is 25, which, multiplied by 4, gives 100, the number of gallons per minute (approximately).

To find the horse power necessary to elevate water to a given height, multiply the total weight of the water in lbs. by the height in feet and divide the product by 33,000 (an allowance of 25 per cent. should be added for water friction, and a further allowance of 25 per cent. for loss in steam cylinder).

The area of the steam piston, multiplied by the steam pressure, gives the total amount of pressure that can be exerted. The area of the water piston multiplied by the pressure of water per square inch gives the resistance. A margin must be made between the power and the resistance to move the pistons at the required speed--say from 20 to 40 per cent., according to speed and other conditions.

To find the capacity of a cylinder in gallons. Multiplying the area in inches by the length of stroke in inches, will give the total number of cubic inches; divide this amount by 231 (which is the cubical contents of a U. S. gallon in inches), and the product is the capacity in gallons.

With the efficient working of pumps certain precautions are necessary. Following are a few hints that will be of service to persons interested in the subject:

Care should be exercised to prevent foreign substances from entering the suction

py. In case of such danger a strainer should be used and the total area of the strain holes should be from two to five times the area of the pipe.

It is of great advantage to have the suction pipe as straight and free as possible. Elbows and valves obstruct the flow of water much more than usually supposed.

Above all other things, the suction pipe should be perfectly air-tight, as a very small leak will supply the pump with so much air that little or no water will be obtained.

It is advantageous, and, when high speed is desired, becomes a necessity, to connect a vacuum chamber to the suction pipe near the pump.

A foot-valve should be used on long or high suctions. Its area should be at least as much as the pipe.

If in an exposed position, the pump should be thoroughly drained after stopping, to prevent injury by frost, by means of the drain-cocks provided for the purpose. When a pump is to remain idle for some time the steam cylinder should be well oiled before stopping.

The stuffing-boxes should be carefully packed so as not to necessitate them being screwed down too tight.

The most economical speed to run a pump is 100 feet per minute.

The friction of liquids in pipes increases as the square of the velocity.

To find the capacity of a Double-Acting Pump in U. S. gallons per minute, multiply together: the area of the water cylinder in inches; the length of the stroke in inches; the number of single strokes per minute. Divide the product by 231. For a Single-Acting Pump take half the number of single strokes. For domestic use water should be kept in wooden or iron tanks. Zinc can be used to advantage. The use of lead-lined tanks is exceedingly dangerous, especially for keeping rain

water.

CAPACITY OF CYLINDRICAL CISTERNS OR TANKS FOR EACH FCOT OF DEPTH (U. S. GALLONS).

THE great philosopher, Plato, defined man as a featherless biped. Thereupon the shrewd old cynic, Diogenese, plucked the feathers from a goose, and, having labeled it "Plato's man,' ," threw it over into the philosopher's class-room.