1 horsepower = 33,000 foot pounds/min. = 550 foot pounds/sec. = 0.746 kilowatt.
1 boiler horsepower = the work of converting 30 lbs. of water/hour from an initial temperature of 100°F to steam at 70 lbs. gauge pressure; or the evaporation of 34.5 lb of water/hour at 212°F into steam at 212°F.
1 watt = 0.00134 horsepower = 44.3 foot pounds/min.
1 kilowatt = 1000 watts = 1.34102 horsepower = 44253.6 foot pounds/min.
1 gram weight = 981 dynes (force) approximately.
Absolute Zero = –273.13°C. = –459.6°F. = 0°K
1 British thermal unit (BTU) = 252 calories (gram ) =778.57 foot pound.
1 gram calorie = 4.185 joules 3.968 x 10-3 BTU = 3.087 foot pounds.
Heat of fusion of ice = 144 BTU/pound.
Heat of vaporization of water = 996.6 BTU/pound.
1 gram-molecular volume of a gas at 760 mm pressure and 0°C. = 22.4 liters.
1 atmosphere = 14.7 lbs./sq. in.=1.0333 kilograms/sq. cm.=760 mm Hg.
1 kilogram/sq. cm. = 0.9677 atmosphere = 14.22 lbs./sq. in.
1 inch (pressure) of mercury = 13.6 inches of water.
Coefficient of expansion of gases = 0.003665/degree C.
Density of dry air at 0°C and 760 mm. = 0.001293 grams/cc.
Mean radius of the earth = 6371 kilometers = 3959 miles.
Mean density of the earth = 5.52 grams/cc.
Density of sea water = 1.025 grams/cc.
1 degree of latitude at 40°lat. = 69 miles.
Acceleration of gravity (sea level lat. 45°) = 980.60 centimeters/sec2 = 32.172 feet/sec2
1 gram/100 cc. = 0.0833 lbs/gallon.
1 Angstrom (Å) = 10-8 centimeter = 0.1 millimicron.
1 micron (µ) = one millionth meter = 0.001 millimeter.