When Scottish inventor James Watt received a patent on his steam engine in 1755, horses were being used to draw coal to a mine’s surface.
After calculating that one horse had the power to haul 330 pounds 100 feet in one minute, he proved that one steam engine could replace an entire herd of horses.
This made Watt wealthy and gave us a formula to interpret engine capacity in horsepower.
The energy from a car’s engine is referred to as “horsepower”.
