# Why is the engine power measured in horsepower?

"While our cosmic ships are furious to the universe ..." We continue to measure the engine power in horsepower. Where did these "horsepower" come from and why in the century of high technologies, wireless information and conquering of the cosmos, we continue to use this unit of measurement?

The term "Horse Power" (horsepower) came up in 1789, Scotlandz James Watt. In those days to raise water, which accumulated at the bottom of the mines, was used either traditional horsepower, or a vapor Machine Newkumn. James Watta managed to construct the car, which in its effectiveness significantly exceeded the brainchild of Newkom and consumed 70% less fuel.

Despite the obvious advantages, the conservative owners of the mines were in no hurry to acquire the development of the Watt. In order to sell your car, it was necessary to describe its advantages. And it means, compare it with the fact that most of the owners of the mines used - with a horse.

Before the weak, the task was to measure, with what force the horse can perform any job. For this, they were invented by the term Horse Power. It is still unknown, as it was that the WATT experiments conducted his experiments, but perhaps he watched how horses pulled out a barrel from the mine. After conducting many observations, James found that the average rate of pulling the horses of the barrel with a volume of 160 l (≈1 barrel) is 3, 6 km / h (≈2 miles / h). Multiplying 2 miles / h per ½ barrel (we consider the power of one horse), we get the result of 1 mile / h × 1 barrel, which in smaller measurements is 33, 000 ftou-pounds *. If you translate the resulting value in watts (which, by the way, was called in honor of James Watt), then find out that one horsepower equals ≈745, 699 W. This value was called "Mechanical Horsepower" and used in the United States and UK. In Russia and Europe, they use a metric horsepower, which determines the power that must be spent on the rise of cargo at 75 kg per 1 meter. Its value is ≈735, 49 watts.

Calculations of computing, and what was with James Watt? With the help of the new term, he could visually show the owners of the mines, how many horses will be able to replace his wonder cars. The result was not forced to wait: the engineer gained popularity and laid the beginning of the industrial revolution in England, and the term "horse forces" introduced by him became so lucky that the centuries were rooted in languages ​​around the world.

* Energy that needs to be expensive to lift the body weighing 1 pound (453, 6 g) to height 1 foot