In use, the top of the piston was connected by a rod to an oscillating beam, the other end of which operated a pump.
Newcomen's engines were in use for more than a century, employed mainly in draining mines where, of course, coal to fire the boilers was free and plentiful, so the deficiencies of the machine could be overlooked. But in truth it was an inefficient device, because the cold water introduced to the cylinder on each cycle meant the cylinder was being alternately heated and cooled, at a heavy cost in fuel.
It was now that James Watt arrived on the scene. He immediately saw the problem when he was asked to repair a model of the Newcomen engine. His solution was to exhaust the steam from the cylinder into a separate chamber, which he called a condenser, where it would be turned back into water.
Not only could the cylinder now be kept at its operating temperature, but it could also be closed to the atmosphere, with steam being introduced at either end alternately, providing two power strokes per cycle instead of one. In fact, it was no longer an 'atmospheric' engine, but a true steam engine which could be used to drain deep mines all over the country.
The savings in fuel were enormous, and when Watt also designed a rotary motion to replace Newcomen's up-and-down beam action, the way was open for the steam engine to power the factories full of spinning mules that were springing up all over Lancashire.
However, it could be argued that Watt's success actually held back development of the steam engine. His partnership with Matthew Boulton in Birmingham produced a stranglehold on the business - Watt's patents were so worded that it was practically impossible for anyone to produce engines without infringing them, and the partners were ruthless in protecting their rights.
Throughout the 1780s and 90s, they stamped down hard on anyone who tried to get involved, so those who had ideas to take steam-engine development forward were forced to experiment in secret and kick their heels. Watt and Boulton themselves never saw the need to go beyond what they had already achieved.
WATT steam engines proliferated in Cornwall in the 18th and 19th centuries, occupying engine houses such as this one, preserved near Redruth. In this case, the later engine turned a wheel that raised or lowered a rope to the pit bottom.The expiration of Watt's patents in 1800 was the signal for a massive leap forward, with Cornishman Richard Trevithick, in particular, taking development onto a new plane with his high-pressure engines which exhausted their spent steam straight into the atmosphere, instead of using a condenser.
It was a short step from there to making the steam engine mobile, but Watt himself was not interested. He left it to men like Trevithick, George Stephenson and Isambard Kingdom Brunel to put the steam engine on wheels and into ships, thereby revolutionising the world of transport.
