File:NewcomenSteamEngine.png

Summary

Newcomen steam engine, Fig.180 by ^[1]

Description

213. The invention of the steam engine. In our age no other machine is of such importance as the steam engine. It furnishes the driving power for running a countless number of machines in our shops and factories, as well as for transportation on land and sea.

Up to about two hundred years ago steam had been used only in various devices, called steam fountains, for raising water. In 1705 the first successful attempt to combine the ideas of these devices into an economical arid convenient machine was made by Thomas Newcomen (1663-1729), a blacksmith of Dartmouth, England. This machine was called an " atmospheric steam engine" (Fig. 180). It consisted of a boiler A, in which the steam was generated, and a cylinder B, in which a piston moved. When the valve V was opened, the steam pushed up the piston P. At the top of the stroke, the valve V was closed, the valve V' was opened, and a jet of cold water from the tank C was injected into the cylinder, thus condensing the steam and reducing the pressure under the piston. The atmospheric pressure above then pushed the piston down again. This machine was used to pump water from mines. It consumed a great deal of fuel, because the cold water cooled the cylinder walls so much that when the steam was turned in, much steam condensed before the piston was raised.

Historical context

Such an engine had been improved by James Watt.

Reference