The second machine is constructed on a similar principle;—a globe moved on a pivot, by means of steam conducted into it from a boiling caldron. The caldron or heated vase, p, in the Second Figure, is to be closely covered with a lid; into which a pipe, o, is inserted at one side of its circumference. This pipe, after rising vertically for a short distance, is bent at right angles. On its horizontal end is placed a small globe, x, kept in its position by a pipe, s, also bent at right angles and fixed to the lid opposite to o, but terminating in a pivot, q, on which the little globe revolves. This globe is furnished with two small pipes, z, w, bent at their extremities and open. The steam from the boiling water in p, rising through the pipe o, is admitted at s into the globe; and issuing through the bent tubes z, w, causes the sphere to revolve as if it were "actuated from within by a spirit. This simple and effective apparatus, though described but as a philosophical toy, is curious, as being the primitive mode in which steam was applied to produce motion, and as conferring on Hero the honour of having invented and constructed the FIRST STEAM ENGINE. † * The Spiritalia was first edited by Commandine, in 1571. It is also printed in the splendid folio collection of the works of the Ancient Mathematicians, published at Paris in 1693. The Greek text is accompanied with a Latin translation. The descriptions of the two machines, we have described, are in page 202 of that edition. It is a remarkable circumstance, too, that this Greek scheme should be revived as an improvement upon the almost No other notice of Steam as a first mover occurs in the works of ancient authors; nor in modern writers until about the year 1563; when one Mathesius, in a volume of sermons, entitled Sarepta, hints at the possibility of constructing an apparatus similar in its operation and properties to those of the modern Steam Engine.* About thirty years after this period, what is called a " Whirling Oelipile" (shewn in the Third Figure,) is described in a book printed at Leipsigt, wherein it is stated to be exceedingly well adapted to the purpose of turning the spit for the cook. And among other economical reasons urged for its adoption, is that "it eats nothing, and gives withal an assurance to those partaking of the feast, whose suspicious natures nurse queasy appetites, that the haunch has not been pawed by the turnspit (in the absence of the housewife's eye), for the pleasure of licking his unclean fingers." A small quantity of water is introduced into the globe, x, (in the Third Figure,) which is rarefied into steam by a fire made under it. The vapour issues at the necks a and b, and by its reaction a continuous motion is generated. Solomon De Caus‡, an eminent French engineer perfect modern mechanism; first by Kempel, a German, about 1785; and by a Mr. Sadler of Oxford in 1791, at which time he obtained a patent for his invention. * Young's Catal. Nat. Philos. p. 263. + In 1597. Les Raisons des Force mouvantes avec divers Desseins de Fontaines, folio, Paris 1624. Dr. Brewster gives the date of 1615 to De Caus's book; if correct, it is probably that of an earlier edition, which we have not seen. |