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Chap. 6.] Piston Steam-Engine described by Worcester .

crown my labours, to re ward my expences, and make my thoughts acqui-esce in way of further inventions ; this making up the whole Century, andpreventing any further trouble to the reader for the present, meaning toleave to posterity a book, wherein, under each of these heads, the means toput in execution, and visible trial, all and every of these inventions, withthe shape and form of all things belonging to them, shall be printed bybrass plates.”

To an ordinary reader all this appears preposterous, nor without thekey can any satisfactory Interpretation be given. The first seems incre-dible, the second impossible, and the third a proof of mental aiienation.But in considering them it should be kept in mind, that Worcester ’s designwas to explain the effects and uses of the mechanism he here refers to,and at 1 the same time to conceal the moving principle. This he has accom-plished in the happiest manner; and in doing it, has furnished a specimenof ingenuity, and of the fertility of his genius, almost equal to the inven-tions themselves. The three problems certainly refer to a cylindricalsteam-engine raising water by means of a pump. In No. 98 he speaksof steam only : this was the primum mobile whose effect -was the same inwhatever direction it was conveyed to the piston ; i. e. whether throughascending, descending, curved, angular or straight tubes, or through anumber of them meeting in the cylinder from every imaginable direction ;the steam from one not interfering with, or being counteracted by, thatfrom others, but the whole “ unanimously and with harmony agreeing,they all augment and contribute strength unto the intended work andOperation,” viz. in pushing the piston along. It seems impossible forWorcester to have selected a feature of äeriform fluids better adaptedfor his purpose, or to have made use of it more skillfully. In concealinghis meaning by riddles, he seems to have equalled the most expert amongthe ancients. 1 In No. 99 he plays in a similar style upon the piston, andhas contrived with admirable tact to contradict (apparently) one of themost palpable maxims in mechanics, and thus to divert prying curiosityinto a wrong track. The piston was attached by its rod to one end of aworking-beam, and a loaded pump-rod to the other, so that when thesteam was turned on, the small piston (which he compares to one pound)was pushed down, and consequently the heavy pump-rod, or the waterraised by it, (compared to a hundred pounds) elevated “ as high as theone pound falleth.” In No. 100 he opens his views still further by statingit to be a water-work, for draining “ all sorts of mines, and furnishing citieswith abundance of water, though never so high seated,” and that its actiondepended upon the two last mentioned inventions (Nos. 98 and 99.) Inother words, he here contemplates the pump and steam-engine as a whole;but lest the device should be too easily apprehended, he throws in a dashof the enigmatical, declaring it was so contrived “ that a child’s forcebringeth up, an hundred foot high, an incredible quantity of water, even[a column] two foot diameter that is, a child could by a lever open andclose the cocks, or valves, by which steam was admitted into the cylinder.The uniformity of the movements of a steam-engine, and the little noiseattending them,—its working incessantly night and day, and the triflingexpense required to keep it in repair, are now well understood.

* Of aneient riddles, that of the Sphynx is one of the neatest. What animal is it thatwalks on four legs in the morning, on two at noon, and on three in the evening ? CEdipusexplained it. The animal, he said, was man, who in the morning of life (in infancy)crept on his hands and feet, at the noon of life walked erect, and in the evening of his4ays snpported himself with a stick.