H is for Horsepower

 Romania, 2011

It excites me that no matter how much machinery replaces the horse, the work it can do is still measured in horsepower.....even in this space age.  And although a riding horse often weighs half a ton, and a big drafter a full ton, either can be led about by a piece of string if he has been wisely trained. This to me is a constant source of wonder, and challenge.

     ~ Marguret Henry, American author (1902-1997)

 

A new morning... a new hard day for beasts of burden. For both man and his horse. And so it has been since the New Stone Age, roughly 10,000 years ago, when man transformed from forager to farmer.

[all photos can be enlarged with a click]

Then came the Industrial Revolution with its machinery. Since these new inventions often replaced the work of horses, it was considered useful to compare the output of machines with the power of draft horses.

Did you know that one horsepower equals 33,000 foot-pounds per minute? So it was determined by James Watt of the unit of power fame.

The story goes that Watt was working with ponies lifting coal at a coal mine, and he wanted a way to talk about the power available from one of these animals. He found that, on average, a mine pony could do 22,000 foot-pounds of work in a minute. He then increased that number by 50 percent and pegged the measurement of horsepower at 33,000 foot-pounds of work in one minute. It is that arbitrary unit of measure that has made its way down through the centuries and now appears on your car, your lawn mower, your chain saw and even in some cases your vacuum cleaner. [source: How Stuff Works]

To learn what other units horsepower are converted to, read here.

The letter of the week is H and this is my link for ABC Wednesday.