But because there was all this incentive to get more coal out of the ground, steam engines were invented to pump water out of the mines. And because those early steam engines were super inefficient, they needed a cheap and abundant source of fuel in order to work, namely coal, which meant they were much more useful to the British than anyone else. So steam engines used cheap British coal to keep British coal cheap, and cheap British coal created the opportunity for everything from railroads to steel, which, like so much else in the Industrial Revolution, created a positive feedback loop. Because they run on rails, railroads need steel, and because it is rather heavy, steel needs railroads. Secondly, there were wages. Britain, and to a lesser extent the Low Countries, had the highest wages in the world at the beginning of the 18th century. In 1725, wages in London were the equivalent of 11 grams of silver per day.