that Mr. Newcomen was as early in his invention as Mr. Savery was in his, only the latter being nearer the court had obtained his patent before the author knew it; on which account Mr. Newcomen was glad to come in as a partner to it’ (System of Hydrostaticks and Hydraulics, 1729, ii. 342). Savery's patent bears date 25 June 1698, so that Newcomen must have been at work at least some time before. Writing in 1730, Dr. John Allen says: ‘It is now more than thirty years since the engine for raising water by fire was at first invented by the famous Captain Savery, and upwards of twenty years that it received its great improvement by my good friend the ever memorable Mr. Newcomen, whose death I very much regret’ (Specimina Ichnographia, 1730, art. 12). It is often asserted by writers on the steam-engine that Newcomen took out a patent, or that he applied for a patent, but was successfully opposed by Savery. After careful search through the documents of the period preserved at the Public Record Office, the writer has failed to find the slightest evidence in support of either of these assertions. There is, however, no sort of doubt that Savery and Newcomen entered into some kind of partnership, the terms of the patent being sufficiently wide to cover Newcomen's improvements as we now know them. It must, at the same time, be remembered that we have no contemporary evidence showing what Newcomen's original invention really was. On 25 April 1699 Savery obtained a special act of parliament prolonging his patent for twenty-one years beyond the original term of fourteen years, so that the patent would not expire until 1733. The business seems to have been eventually taken up by a committee, and in the appendix to Bald's ‘Coal Trade in Scotland’ there will be found a copy of articles of agreement for the construction of an undoubted Newcomen engine at Edmonstone Colliery, Midlothian, between Andrew Wauchope, the proprietor of the colliery, and certain persons living in London, described as ‘the committee authorised by the proprietors of the invention for raising water by fire.’ The agreement is dated 1725, one of the conditions being that Wauchope should pay to the committee a royalty of 80l. per annum ‘for, and during and until the full end and period of the said John Meres and proprietors aforesaid, their grant and license for the sole use of said engine, being eight years complete next following and ensuing,’ which brings matters to 1733, the very year in which Savery's act of parliament expired. The John Meres mentioned was in all probability Sir John Meres, F.R.S., at one time governor of the York Buildings Waterworks Company [see under Meres, Francis]. It seems then certain that Newcomen's engine was regarded as an improvement upon Savery's machine, and one which was covered by the original patent granted to Savery in 1698. Attention may also be directed to an advertisement in the ‘London Gazette’ for 11–14 Aug. 1716 as follows: ‘Whereas the invention for raising water by the impellant force of fire, authorised by parliament, is lately brought to the greatest perfection, and all sorts of mines, &c., may be thereby drained, and water raised to any height with more ease and less charge than by the other methods hitherto used, as is sufficiently demonstrated by diverse engines of this invention now at work in the several counties of Stafford, Warwick, Cornwall, and Flint. These are, therefore, to give notice that if any person shall be desirous to treat with the proprietors for such engines, attendance will be given for that purpose every Wednesday at the Sword Blade Coffee House in Birchin Lane, London …’
According to Desaguliers in his ‘Experimental Philosophy,’ the second volume of which appeared in 1744: ‘About the year 1710 Thomas Newcomen, ironmonger, and John Calley, glazier, of Dartmouth, in the county of Southampton [sic] (anabaptists) made then several experiments in private, and having brought [their engine] to work with a piston, &c., in the latter end of the year 1711 made proposals to draw the water at Griff, in Warwickshire; but their invention meeting not with reception, in March following, thro' the acquaintance of Mr. Potter of Bromsgrove, in Worcestershire, they bargain'd to draw water for Mr. Back of Wolverhampton, where, after a great many laborious attempts, they did make the engine work; but not being either philosophers to understand the reasons, or mathematicians enough to calculate the powers and to proportion the parts, very luckily by accident found what they sought for’ (Experimental Philosophy, ii. 532). He then proceeds to state that the condensation by injection of water inside the cylinder instead of outside, according to Savery's practice, was discovered accidentally, and that the engine was rendered self-acting by the ingenuity of Humphrey Potter, a boy employed to mind the engine, who contrived a series of catches and strings worked from the beam, by which the several valves were opened and closed in due order. He assigns to Henry Beighton [q. v.] in 1718 the invention of the ‘plug rod,’ as it was afterwards called, provided
