In this day and age of powerful machines, there is a big chance you’ve heard about horsepower. From heavy machinery, to cars, to air conditioners, to lawnmowers, the term horsepower is used to describe an engine’s power. But have you ever wondered why of all animals the horse was chosen as the benchmark for power?
The reason is pretty literal, actually.
In the early 1780s, Scottish engineer James Watt was looking for a compelling way to market his new invention – a steam engine superior to the then classic Newcomen steam engine. Many of his prospective customers at that time used horses to power their operation, so Watt had to come up with a new unit of measurement that he could use to illustrate the advantage of using his steam engine as opposed to horses. Hence, horsepower.
The way Watt came up with the numbers he did is still up for discussion, but after doing the experiments that he did, he figured out that a typical draft horse could do about 32,400 foot-pounds of work in 60 seconds, and maintain that power rate for the entire work day.
That means that, by Watt’s approximation, a draft horse could lift 32,400 pounds of material one foot in one minute. After doing some rounding up, Watt settled for 33,000 foot-pounds per minute for one horsepower (hp).
[youtube https://www.youtube.com/watch?v=_L_AUeM0Y48]
Video Source: TheShootingstar31
Of course, Watt’s estimates were very generous, as the horses involved in his experiments were far from mutants! But that wasn’t Watt’s original intention anyway. By overestimating what a typical horse could do, Watt made sure that his product would always perform better than the real horses.
The unit of measure horsepower became popular thanks to the invaluable contribution of Watt’s engine during the industrial revolution. Today, however, the SI unit of power, the Watt, which was named in tribute to James Watt, is progressively replacing horsepower in most applications.
