So you’ve just bought yourself a brand new sportscar with a 655 horsepower engine (you probably robbed a bank or something). But what does it all mean?The term horsepower dates back to James Watt, of Industrial Revolution fame. He figured out that the average horse could turn a mill wheel of 12 foot radius 144 times in an hour, so 1hp = pulling 180 pounds for 180 feet for 1 minute.
Ordinary humans can produce 1 hp very briefly, and sustain 0.1hp for a few minutes. Trained athletes can manage up to 2.5hp briefly, and can sustain about 0.3hp. So a steam engine with 5hp could do as much work as 50 human employees in a given time. No-brainer, really.
Nowadays it just seems mean to continue comparing our machines to horses. It takes about 1/10 of a horse to run your television set, and about 40 to run your kettle. We don’t need to keep rubbing it in...
