USEFUL CONSTANTS, ETC.
Reading edition
1 pint of water weighs a pound and a quarter.
1 gal. of water = .1605 cu. ft. = 10 lb. of water at 62° F.
1 knot = 6080 ft. = 1.15 statute miles.
1 lb. (avoirdupois) = 7,000 grains = 453.6 grammes.
1 lb. (Troy) = 5,760 grains.
1 English h. p. = 33,000 ft. lbs. of work done per min. = 746 watts.
1 French h. p. or force de cheval = 4,500 kilogram metres per min. = .9863 English h. p.
1 English h. p. = 1.01385 French force de cheval.
1 board of trade electrical unit = 1,000 watts per hour.
Volts X amperes = watts.
The pressure of one atmosphere = 14.7 lbs. per sq. in. = 2,116 lbs. per sq. ft. = a column of mercury 760 m/m high.
A column of water 2.3 ft. high corresponds to a pressure of 1 lb. per sq. in.
Cubic inches of cast iron X 0.26 = lbs. avoirdupois.
Cubic inches of wrought iron X 0.28 = lbs. avoirdupois.
Thickness of wrought iron plate in inches X 40 = lbs. per sq. ft.
Sectional area of wrought iron in inches X 3.34 = lbs. per lineal ft.
Dia. of wrought iron in inches squared X 2.64 = lbs. per lineal ft.