452
fcTKAM-ENGINES.
most useful of purposes, al9o his ideas for short-hand tele-graphs, floating-baths, escutcheons for locks, moulds for can-dles, and a mode to disengage horses from a carriage, afterthey have taken fright; -which, with several others, pro-claim the originality and ingenuity of his mind.
Since his time, another design upon the same principle,has been projected by Captain Thomas Savery, a commis-sioner of sick and wounded, who, in the year 1698, obtaineda patent for “ a new invention for raising water, and occa-sioning motion to all sorts of mill-work, by the impellentforce of fire.” This patent bears date the 25th Jnly, 16 ofWilliam III . anno 1698. The patent states, that the inven-tion will be of great use for drawing of mines, serving townswith water, and working all sorts of mills. “ Mr. Savery,June 14th, 1699, entertained the Royal Society with show-ing a model of his engine for raising water by help of fire,which he set to work before them; the experiment succeededaccording to expectation.” 1
The above memoir is accompanied with a copper-platefigure, with references by way of description; from whence,it appears, that the engine then shown by Captain Savery,was for raising water, not only by the expansive force ofsteam, like the Marquis of Worcester’s, but also by thecondensation of steam, the water being first raised by thepressure of a rarefied atmosphere to a given height, by theexpansive force of steam, in the same manner as the Marquisproposed. This action was performed alternately in tworeceivers, so that while the vacuum formed in one wasdrawing up water from the well, the pressure of steam in theother was forcing up water into the reservoir; but bothreceivers being supplied by one suction-pipe and one forcing-pipe, the engine could be made to keep a continual stream,so as to suffer very little interruption. This engine of Cap-tain Savery’s displays much ingenuity, and is almost as per-fect in its contrivance as the same engine hath been madesince his time. We regret, that without a figure we cannotsupply a perfect description of it.
However, it appears, that it was necessary to have twoboilers, or vessels of copper, one large and the other smaller;those hoilers have a gauge-pipe inserted into the smallerboiler, within eight inches of its bottom, and about thecentre of the side of the larger boiler; the small boiler mustbe filled quite full of water, and the larger one only abouttwo-thirds full. The fire is then to be lighted beneath the