Dear Editor,
Regarding the interview with Andrew Wilson in the October issue of en, in the interests of accuracy, the steam engine was not invented in 1776. In that year the first Boulton and Watt pumping engine was built and operated. It was a development of the Newcomen pumping engine of 1712. It employed Watt’s patent separate condenser using atmospheric pressure rather than steam pressure. It was reciprocating, with no rotation. The crank and flywheel was patented in 1780 by Wasbrough, Steed and Pickard, so Watt patented his own sun and planet gear in 1781. Boulton and Watt were then able to build rotating engines using double-acting cylinders and governors.
The true steam engine using steam pressure was the work of Trevithick in 1800. Watt was not an enthusiast of high-pressure steam. All this development was dependent on Abraham Derby working out how to smelt iron using coke in 1709. Charcoal became scarce and expensive, and coke permitted larger blast furnaces. In 1783 Henry Cort developed puddling and rolling also using coke. The whole process depended on many people – notably Brindley, Bridgewater and Gilbert. Without Boulton and Murdoch, Watt would have made little progress – they needed each other. James Watt invented many things – it’s a pity that people attribute to him something he did not invent.
