Historic images from the Welcome Collection. This is a Newcomen Engine, the first useful steam engines, mainly used to pump water out of mines.
The Boulton-Watt engine, which added a condenser and other improvements. Circa 1770. Boulton and Watt did not sell these; instead they installed them to replace Newcomen engines and asked the factory owners to rent them for half what they had been paying for coal. They were so much more efficient that Boulton and Watt got vastly rich off the difference.