JAMES WATT'S role in the evolution of steam power is often misrepresented. He did not invent the steam engine, despite all that eighteenth-century propaganda about him watching a kettle boiling on the kitchen range and noticing how the steam raised the lid. Someone had noticed that a long time before him.
In fact, engines using steam were running well before Watt was born. The Scot's claim to fame is based on the radical improvements he made to Thomas Newcomen's atmospheric engine, which turned steam into the major power source of the Industrial Revolution. He truly introduced the Age of Steam.
Yet a closer look at his story suggests that Watt was by no means the great guiding light of the Industrial Revolution that so many people assume. His proprietorial attitude to steam power may well have delayed Britain's industrial progress for a decade or more, with far-reaching consequences.
Watt was born in Greenock on the River Clyde in Scotland in 1736, the son of a merchant. At 18, he went on horseback to London to train as a mathematical instrument maker. He returned to perform this job for Glasgow university for six years and still found time to supplement his income by carrying out surveys for the Forth and Clyde, Caledonian and other canals.
It was while repairing a model of a Newcomen engine for the university in 1763 that he noticed the deficiencies of the machine, and had the idea for a separate condenser.
Newcomen's engine had worked by using steam to create a vacuum beneath a piston inside a cylinder. The vacuum was formed by condensing the steam using a water spray inside the cylinder, allowing atmospheric pressure to force the piston downwards.
Watt realised that cooling the cylinder in this way on every stroke, then heating it again with the introduction of more steam, was a massive waste of energy. His solution was to divert the spent steam out of the cylinder and into a separate chamber, called a condenser, where it was cooled. This allowed the cylinder itself to remain hot and more efficient throughout the cycle.
Newcomen's cylinder had been open at the top, allowing the atmosphere to do the work - the steam he used was at little
A WATT engine of 1787, equipped with rotatory motion and the engineer's patent governor. The boiler is on the extreme left, supplying steam to the cylinder, whose piston raises and lowers the beam which turns the big wheel.But Watt decided to make the steam do all the work. He sealed the top of the cylinder, increased steam pressure and introduced it alternately to the top and bottom of the piston. The result was a huge increase in power and efficiency.
Watt was by no means a rich man, and he knew he needed money and facilities to develop his idea. His problem seemed to be solved when he went into partnership with Dr John Roebuck, proprietor of the Carron Ironworks near Falkirk.
