One of the best varnishes for smoke stacks or steam pipes is good asphaltum dissolved in oil of turpentine.
Iron or steel immersed warm in a solution of carbonate of soda (washing soda) for a few minutes will not rust.
Cement to fasten iron to stone.—Take 10 parts of fine iron filings, 30 parts of plaster of Paris, and ½ part of sal ammoniac; mix with weak vinegar to a fluid paste and apply at once.
Cement for joints.—Paris white, ground, 4 lbs.; litharge, ground, 10 lbs.; yellow ochre, fine, ½ lb.; ½ oz. of hemp, cut short; mix well together with linseed oil to a stiff putty. This cement is good for joints on steam or water pipes; it will set under water.
The average consumption of coal for steam boilers is 12 pounds per hour for each square foot of grate surface.
One ton of coal is equivalent to two cords of wood for steam purposes.
Doubling the diameter of a pipe increases its capacity four times.
A cubic foot of water contains 7½ gallons.
A gallon weighs 8⅓ pounds.
Water expands ¹/₉ of its bulk in freezing.