James Watt


The idea of using steam to drive a piston in order to do mechanical work was attempted many years before James Watt was even born. The "Newcomen" engine was first built in 1712, and was used for tasks such as pumping water out of mines. They were large and inefficient, however, and expensive to build and operate. In 1754 James Watt, who worked in a machine shop at Glasgow University, made an important improvement to a Newcomen engine, by adding dual chambers, one where the "work" of the engine was done by the steam, and the other where the steam was cooled to prevent the engine from over-heating.

James Watt's novel idea is usually illustrated by a tea-kettle. A kettle with no lid may take a long time to heat, but it will never explode. A kettle with a tightly closed lid will heat up very efficiently, but will ultimately explode. A tea-kettle on the other hand, is covered, but allows enough steam to escape to avoid catastrophe. In Watt's engine, the chamber where the work was done, was separated from the chamber where the steam was cooled by a similar mechanism. Watt's engine, therefore, was both efficient and safe.

Although Watt's his original idea was sound, and he was able to obtain a patent for it, many years elapsed before it could be successfully manufactured, and during this time Watt developed partnerships with several other engineers, iron workers, and businessmen, and had to solve a variety of difficult problems. Watt's most important long-term partner was Boulton, who had the business sense that Watt lacked. In addition to helping manufacture the first mass producible Watt Steam Engines in 1776 (eight years after Watt completed his prototype), Boulton assisted with several other innovations. In 1781 they patented a steam driven rotational motor which was more portable than their piston driven reciprocal (up-down) engine, and later they developed a governor that helped control the speed at which their engines ran. Both of these inventions made their engine much more practical for manufacturing tasks.

Boulton and Watt were granted numerous patents for these inventions but instead of licensing them, they incorporated and began to mass produce steam engines, and the industrial revolution swung into high gear.

Key events during the life of James Watt:

James Watt born in Scotland to a shipwright.
Set up an instrument shop at Glasgow University.
Began studying steam engines.
Repaired a "Newcomen" engine owned by the University.
Married Margaret Miller.
Produced first working model of the 'Watt' engine (with separate chambers for piston and steam).
Difficult manufacturing problems were finally solved. First commercial engines produced.
Rotational motor driven by steam power introduced.
Boulton and Watt incorporated to mass produce steam engines.
Retired and passed business on to sons.
Death of Watt.

Other Resources

Story Links
Book Links
James Watt and the Invention of the Steam Engine  in  Great Inventors and Their Inventions  by  Frank P. Bachman
James Watt and the Teakettle  in  Thirty More Famous Stories Retold  by  James Baldwin
Story of the Steam-Engine  in  The Struggle for Sea Power  by  M. B. Synge

Image Links

James Watt
 in Great Inventors and Their Inventions

Watt and the Teakettle
 in Great Inventors and Their Inventions

Watt's Workroom at Hearthfield
 in Great Inventors and Their Inventions

Watt and the Teakettle
 in Thirty More Famous Stories Retold

Short Biography
Joseph Black Glasgow Chemist who befriended Watt and help him with his engine.
John Roebuck First financial backer of Watt's engine. Went bankrupt.
Matthew Boulton Long term business partner of James Watt.