Editing Newcomen atmospheric engine (section)

===Savery's "Miner's Friend"===
In 1698 [[Thomas Savery]] patented a steam-powered pump he called the "Miner's Friend",<ref>[http://www.history.rochester.edu/steam/savery/ The Miners Friend] {{webarchive|url=https://web.archive.org/web/20090511121051/http://www.history.rochester.edu/steam/savery |date=11 May 2009 }}</ref> essentially identical to Somerset's design and almost certainly a direct copy.{{citation needed|date=December 2022}}<ref>{{Cite web |title=Thomas Savery and the Beginning of the Steam Engine |url=https://www.thoughtco.com/thomas-savery-steam-engine-4070969 |access-date=2024-11-06 |website=ThoughtCo |language=en}}</ref> The process of cooling and creating the vacuum was fairly slow, so Savery later added an external cold water spray to quickly cool the steam.

Savery's invention cannot be strictly regarded as the first steam "engine" since it had no moving parts and could not transmit its power to any external device. There were evidently high hopes for the Miner's Friend, which led Parliament to extend the life of the patent by 21&nbsp;years, so that the 1699 patent would not expire until 1733. Unfortunately, Savery's device proved much less successful than had been hoped.

A theoretical problem with Savery's device stemmed from the fact that a vacuum could only raise water to a maximum height of about {{convert|30|ft|m|0|abbr=on}}; to this could be added another {{convert|40|ft|m|0|abbr=on}}, or so, raised by steam pressure. This was insufficient to pump water out of a mine. In Savery's pamphlet, he suggests setting the boiler and containers on a ledge in the mineshaft and even a series of two or more pumps for deeper levels. Obviously these were inconvenient solutions and some sort of mechanical pump working at surface level – one that lifted the water directly instead of "sucking" it up – was desirable. Such pumps were common already, powered by horses, but required a vertical reciprocating drive that Savery's system did not provide.  The more practical problem concerned having a boiler operating under pressure, as demonstrated when [[Thomas Savery#Application of the steam pump|the boiler of an engine at Wednesbury exploded]], perhaps in 1705.