The History of Steam Engines

James Watt - inventor of steam engine
James Watt the inventor of the modern steam engine.

Thomas Savery (1650-1715)

Thomas Savery was an English military engineer and inventor. In 1698, he patented the first crude steam engine, based on Denis Papin's Digester or pressure cooker of 1679.

Savery had been working on solving the problem of pumping water out of coal mines when he came up an idea for an engine powered by steam. His machine consisted of a closed vessel filled with water in which steam under pressure was introduced.

This forced the water upwards and out of the mine shaft. A cold water sprinkler was then used to condense the steam. This created a vacuum which sucked more water out of the mine shaft through a bottom valve.

Thomas Savery later worked with Thomas Newcomen on the atmospheric steam engine. Among Savery's other inventions was an odometer for ships, a device that measured distance traveled.

To learn more about Thomas Savery the inventor, check out his biography here. Savery’s description of his crude steam engine can be found here.

Thomas Newcomen (1663-1729)

Thomas Newcomen was an English blacksmith who invented the atmospheric steam engine. The invention was an improvement over Thomas Slavery's previous design.

The Newcomen steam engine used the force of atmospheric pressure to do the work. This process begins with the engine pumping steam into a cylinder. The steam was then condensed by cold water, which created a vacuum on the inside of the cylinder.

The resulting atmospheric pressure operated a piston, creating downward strokes. With Newcomen's enginee, the intensity of pressure was not limited by the pressure of the steam, a departure from what Thomas Savery had patented in 1698.

In 1712, Thomas Newcomen, together with John Calley, built their first engine on top of a water filled mine shaft and used it to pump water out of the mine.

The Newcomen engine was the predecessor to the Watt engine and it was one of the most interesting pieces of technology developed during the 1700's.

To learn more about Thomas Newcomen and his steam engine check out this biography here. Photos and a diagram of Newcomen’s steam engine can be found at Niagara college’s professor Mark Csele’s website.

James Watt (1736-1819)

Born in Greenock, James Watt was a Scottish inventor and mechanical engineer who was renowned for the improvements he made to the steam engine. While working for the University of Glasgow in 1765, Watt was assigned the task of repairing a Newcomen engine that was deemed inefficient but the best steam engine of its time. That started the inventor working on several improvements to Newcomen's design.

Most notable was Watt's 1769 patent for a separate condenser connected to a cylinder by a valve. Unlike Newcomen's engine, Watt's design had a condenser that could be cool while the cylinder was hot. Eventually Watt's engine would become the dominant design for all modern steam engines and helped bring about the industrial revolution.

A unit of power called the Watt was named after James Watt. the Watt symbol is W, and it is equal to 1/746 of a horsepower, or one volt times one amp.