Here is information about non-metric units of power.
Horsepower: A workhorse can lift 550 pounds 1 foot in the air in 1 second; that is 1 horsepower. Engines are measured in horsepower. A 10-horsepower engine can do the work of ten horses.
Manpower: An average man lifts 55 pounds 1 foot high in 1 second.
Candlepower: The amount of light given off by a candle of a specific size, shape, type of tallow, and type of wick. The brightness of an electric light is measured in candlepower.
Megaton: A megaton is the blasting power of a hydrogen bomb. One megaton has the power of 1 million tons of TNT.