The Industrial Revolution led to many inventions that changed manufacturing. Arkwright's water frame and Crompton's spinning mule automated thread production. Cartwright's power loom used steam power. These inventions required new factories and labor systems. The steam engine was also improved through the work of Savery, Newcomen, and Watt, allowing for coal mining and powering other machines. Henry Cort's puddling furnace produced stronger iron. These changes grew the population and led to urbanization. They also created new social classes as factory working conditions were difficult, especially for women and children.