The first thing that strikes you is the presence of a white horse right at the start of the guided tour. Is this presence insignificant? That's what we'll try to determine throughout this article. At the end of the 18th century, horses were the most common way to move loads. They were also used to power machines, for example, to draw water from wells. With the invention of the steam engine, it became necessary to establish a conversion between their power and that which can be obtained from a horse. For example, questions like: what power must a steam engine have to replace a horse drawing water from a well? The great British scientist James Watt tackled this problem and found a solution. He used as a reference the power a horse develops when it is made to lift a certain weight from a certain height for a certain time. Thus was born "horsepower," the power required to lift a 55-pound weight 10 feet in 1 second. The rest of the world, using the metric system, defined "horsepower" as the power developed by a horse to lift a 1 kg mass 1 meter in 1 second. A mass of 1 kg weighs 9.81 newtons, because the value of the newton is given by the acceleration due to gravity (Earth's gravity) and is conventionally (it's an average) 9.81 m/s². One horsepower in the metric system, or hp, is therefore equal to 1 × 75 kg × 9.81 m/s², or 735.49875 W. When steam engines began to replace horses, their power was expressed in horsepower. This practice persists, and we still use hp and hp. PS: To write this article, we were inspired by an article published on Futura Planet. If you liked it, click "like" or share it. www.kasparts.com
