Boulton to Watt, 21 June 1781
Matthew Boulton and James Watt’s main business was building steam pumping engines (‘fire engines’) to keep mines free of water. However, Boulton saw it was necessary to find a new innovation for sale in new areas. He knew that mill owners were very keen to be able to use steam power to drive their machinery and this encouraged James Watt to come up with a successful design. Watt had made an experimental ‘rotary engine’ or ‘steam wheel’ in 1769, but it had not been a practical success. Now with Boulton’s stimulus, Watt adapted his pumping engine to produce rotary power, and the first of these machines was set to work in 1782. Improvements such as the double-acting piston and parallel motion soon followed. Boulton was correct in his forecast of the demand for rotary power. Of the 500 or so engines the firm built until 1800, over 300 were rotative engines.
The success of the steam engine for driving machinery was soon recognised as a significant source of the wealth that was flowing into Britain. One reason for this was an article on the history of the steam engine that appeared in the third edition of the Encyclopaedia Britannica in 1797. Written by John Robison, a great friend of Watt, the piece gave Watt almost exclusive credit for the invention of the steam engine and high praise. An obituary for Watt, written in 1819 by Francis Jeffrey (later to be Lord Advocate of Scotland), eulogised the steam engine and said of Watt: ‘It is to the genius of one man, too, that all this is mainly owing; and certainly no man ever before bestowed such a gift on his kind.’ This obituary was widely read and frequently reprinted. James Watt's importance in national life was even compared to that of Shakespeare and a large statue of him was installed in St Paul’s Cathedral in 1834.