The term "horsepower" was created by James Watt, an engineer
who lived from 1736-1819, famous for his work on improving the performance
of steam engines.
Watt was working
with ponies lifting coal out of a coal mine, and he decided to come
up with a measurement that would describe the amount of power that one
animal could pull.
He found that an average mine pony could do 22,000 foot-pounds of work
a minute. He then increased it by 50% and called that one horsepower:
33,000 foot-pounds of work in one minute.
Basically, a horsepower
means this: According to Watt a horse can do 33,000 foot-pounds of work
every minute. A horse pulling coal out of a mine, exerting 1 horsepower,
will raise 330 pounds of coal 100 feet in one minute, or 33 pounds of
coal 1,000 feet in one minute.
Fun fact: A horse
producing 1 horsepower would burn 641 calories in an hour if it were
Today we see the
horsepower measurement used in vehicles, lawn mowers, chainsaws, and
other motors. It's another example of how the horse has influenced our
way of life.