Thomas Savery
Thomas Savery | |
|---|---|
 | |
| Born | c. 1650 |
| Died | 1715 |
| Nationality | English |
| Occupation | Engineer |
Thomas Savery (c. 1650–1715) was an English inventor, born at Shilstone, a manor house near Modbury, Devon, England.
Career
Savery became a military engineer, rising to the rank of Captain by 1702, and spent his free time performing experiments in mechanics. In 1696 he took out a patent for a machine for polishing glass or marble and another for "rowing of ships with greater ease and expedicion than hitherto beene done by any other" which involved paddle-wheels driven by a capstan and which was dismissed by the Admiralty following a negative report by the Surveyor of the Navy, Edmund Dummer.[1]
Savery also worked for the Sick and Hurt Commissioners, contracting the supply of medicines to the Navy Stock Company, which was connected with the Society of Apothecaries. His duties on their behalf took him to Dartmouth, which is probably how he came into contact with Thomas Newcomen.
First steam engine mechanism
On 2 July 1698 Savery patented an early steam engine, "A new invention for raiseing of water and occasioning motion to all sorts of mill work by the impellent force of fire, which will be of great use and advantage for drayning mines, serveing townes with water, and for the working of all sorts of mills where they have not the benefitt of water nor constant windes."[2] He demonstrated it to the Royal Society on 14 June 1699. The patent has no illustrations or even description, but in 1702 Savery described the machine in his book The Miner's Friend; or, An Engine to Raise Water by Fire[3], in which he claimed that it could pump water out of mines.
Savery's engine had no piston, and no moving parts except from the taps. It was operated by first raising steam in the boiler; the steam was then admitted to the working vessel, allowing it to blow out through a downpipe into the water that was to be raised. When the system was hot and therefore full of steam the tap between the boiler and the working vessel was shut, and if necessary the outside of the vessel was cooled. This made the steam inside it condense, creating a partial vacuum, and atmospheric pressure pushed water up the downpipe until the vessel was full. At this point the tap below the vessel was closed, and the tap between it and the up-pipe opened, and more steam was admitted from the boiler. As the steam pressure built up, it forced the water from the vessel up the up-pipe to the top of the mine.
Savery took great care to stress how powerful his engine was, and was the first to use the term "horsepower". However, his engine had four serious problems. First, every time water was admitted to the working vessel much of the heat was wasted in warming up the water that was being pumped. Secondly, the second stage of the process required high-pressure steam to force the water up, and the engine's soldered joints were barely capable of withstanding high pressure steam and needed frequent repair. Thirdly, although this engine used positive steam pressure to push water up out of the engine (with no theoretical limit to the height to which water could be lifted by a single high-pressure engine) practical and safety considerations meant that in practice, to clear water from a deep mine would have needed a series of moderate-pressure engines all the way from the bottom level to the surface. Fourthly, water was pushed up into the engine only by atmospheric pressure (working against a condensed-steam 'vacuum'), so the engine had to be no more than about 30 feet (9.1 m) above the water level – requiring it to be installed, operated, and maintained far down in the mine.
Rawruh
Application of the engine
A newspaper in March 1702 announced that Savery's engines were ready for use and might be seen on Wednesday and Saturday afternoons at his workhouse in Salisbury Court, London, over against the Old Playhouse.
One of his engines was set up at York Buildings in London. According to later descriptions this produced steam 'eight or ten times stronger than common air' (i.e. 8-10 atmospheres), but blew open the joints of the machine, forcing him to solder the joints with spelter.[4]
Another was built to control the water supply at Hampton Court, while another at Campden House in Kensington operated for 18 years.[5]
A few Savery engines were tried in mines, an unsuccessful attempt being made to use one to clear water from a pool called Broad Waters in Wednesbury (then in Staffordshire) and nearby coal mines. This had been covered by a sudden eruption of water some years before. However the engine could not be 'brought to answer'. The quantity of steam raised was so great as 'rent the whole machine to pieces'. The engine was laid aside, and the scheme for raising water was dropped as impracticable.[6][7] This may have been in about 1705.[7]
Another engine was proposed in 1706 by George Sparrow at Newbold near Chesterfield, where a landowner was having difficulty in obtaining the consent of his neighbours for a sough to drain his coal. Nothing came of this, perhaps due to the explosion of the Broad Waters engine.[7] It is also possible that an engine was tried at Wheal Vor, a copper mine in Cornwall.[8]
Inspiration for later work
Several later pumping systems may be based on Savery's pump. For example, the twin-chamber pulsometer steam pump was a successful development of it.[9]
See also
Further reading
- Savery, Thomas (1827). The Miner's Friend: Or, an Engine to Raise Water by Fire. S. Crouch.
{{cite book}}: Cite has empty unknown parameter:|coauthors=(help) - Smiles, Samuel (1865). Lives of Boulton and Watt. Lippincott.
- There are countless modern day reprints: Lives of Boulton and Watt. ISBN 1425560539., Lives of Boulton and Watt. ISBN 1406798630., Lives of Boulton and Watt. ISBN 1845883713..
- Reprinted in Appendix B of: Savary, A.W. (1893). A Genealogical and Biographical Record of the Savery Families and of the Severy Family. Lippincott.
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Notes
- ^ Fox, Celina (2007). "The Ingenious Mr Dummer: Rationalizing the Royal Navy in Late Seventeenth-Century England" (PDF). Electronic British Library Journal. p. 25. Retrieved 6 October 2009.
- ^ Jenkins, Rhys (1936). Links in the History of Engineering and Technology from Tudor Times. Ayer Publishing. p. 66. ISBN 0836921674.
{{cite book}}: Cite has empty unknown parameter:|coauthors=(help) - ^ Savery, Thomas (1827). The Miner's Friend: Or, an Engine to Raise Water by Fire. S. Crouch.
{{cite book}}: Cite has empty unknown parameter:|coauthors=(help) - ^ L.T.C. Rolt and J. S. Allen, The Steam Engine of Thomas Newcomen (Landmark Publihsing, Ashbourne 2007), pp. 27-28
- ^ E. I. Carlyle, 'Savery , Thomas (1650?–1715)', rev. Christopher F. Lindsey, Oxford Dictionary of National Biography, Oxford University Press, 2004, accessed 29 April 2006 URL
- ^ Richard Wilkes of Willenhall, quoted in S. Shaw, History and Antiquities of Staffordshire (1798-1801) II(1), 120
- ^ a b c P. W. King. 'Black Country Mining before the Industrial Revolution' Mining History: The Bulletin of the Peak District Mines History Society 16(6), 42-3.
- ^ Earl, Bryan (1994). Cornish Mining: The Techniques of Metal Mining in the West of England, Past and Present (2nd ed.). St Austell: Cornish Hillside Publications. p. 38. ISBN 0-9519419-3-3.
- ^ SPP Pumps