Illustration of Newcomen's steam engine taken from page 112 of "George Square, Glasgow; and the lives of those whom its statues commemorate, etc" by Thomas (of Glascow) Somerville, 1891. The atmospheric engine invented by Thomas Newcomen in 1712, often referred to simply as a Newcomen engine, was the first practical device to harness the power of steam to produce mechanical work. Newcomen engines were used throughout Britain and Europe, principally to pump water out of mines, starting in the early 18th century. James Watt's later Watt steam engine was an improved version of the Newcomen engine. As a result, Watt is today better known than Newcomen in relation to the origin of the steam engine. Thomas Newcomen (February 1664 - August 5, 1729) was an English inventor, ironmonger by trade and a Baptist lay preacher by calling.