Doubling the diameter of a pipe, increases its capacity four times.
One cubic foot of anthracite coal weighs about 53 lbs.
One cubic foot of bituminous coal weighs from 47 to 50 pounds.
A gallon of water (U. S. standard) weighs 8-1/3 pounds and contains 231 cubic inches.
A cubic foot of water contains 7-1/2 gallons, 1728 cubic inches and weighs 62-1/2 pounds.
To find the number of pounds of water a cylindrical tank contains, square the diameter, multiply by .785 and then by the height in feet. This gives the number of cubic feet which multiplied by 62-1/2 gives the capacity in pounds of water. Divide by 7-1/2 and this gives the capacity in gallons.
A horse-power is equivalent to raising 33,000 pounds 1 foot per minute, or 550 pounds 1 foot per second.
The friction of water in pipes is as the square of velocity. The capacity of pipes is as the square of their diameters; thus, doubling the diameter of a pipe increases its capacity four times.
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 the horse-power necessary to elevate water to a given height, multiply the weight of the water elevated per minute in pounds by the height in feet, and divide the product by 33,000 (an allowance should be added for water friction, and a further allowance for loss in steam cylinder, say from 20 to 30 per cent).