[_A Fire Water-work._] This is that great invention which has popularized and preserved the fame of the Marquis of Worcester in the public mind. Had the whole of the Century been destroyed, with the exception of this 68th article, enough would have remained to satisfy any engineer, that the Marquis had achieved a grand discovery. We shall proceed to notice what information books and the patent records would afford, to stimulate his inquiries into the possible practical application of the effects, resulting from the action of fire on water in close vessels. The work which has, from being often quoted, acquired especial notice on this subject is, “Les Raisons des forces Mouvantes avec diverses Machines. Par Salomon de Caus,” folio, published at Frankfort, 1615, in which, at page 4, theorem V, under the title, “_L’eau montera par aide du feu, plus haut que son niveau_,” it is illustrated and described as follows:--“Le troisiesme moyen de faire monter, est par l’aide du feu, dont il se peut faire diverses machines, i’en donneray icy la demonstration d’une. Soit une balle de cuiure marquee A. bien soudee tout a lentour, à laquelle il y aura un souspiral marqué D, par ou lon mettra leau, et aussi un tuyau marqué B, C, qui sera soudé en haut de la balle, et le bout C, aprochera pres du fond, sans y toucher, apres faut emplir ladite balle d’eau par le souspiral, puis le bien reboucher et le mettre sur le feu, alors la chaleur donnant contre ladite balle, fera monter toute leau, par le tuyau B, C.” See also Figuier’s “Exposition et Histoire des principales découvertes Scientifiques Modernes.” Tome premier. Paris, 1862, p. 25. [Illustration: De Caus’ Fountain.] The adjoining engraving is exactly traced from the original, of which it is, in every respect, a faithful copy. It represents a globular metallic vessel A, with a jet and stop-cock at B, and another stop-cock at D, through which water can be injected by means of a syringe. The jet B, is the top end of a pipe C, which nearly touches the bottom of the inside of the hollow sphere. Supposing the globe to be half or two thirds full of water, and placed on a fire, the heat will presently raise a quantity of steam, which, as it increases in quantity, will occupy the upper empty space of the sphere, and by its pressure on the surface of the boiling water, cause the same to rise rapidly up the vertical pipe C, and produce the jet-d’eau above B, the instant the stop-cock is opened. And this operation will continue so long as any water remains for the bottom end of the pipe C, to dip into; after which it can only be renewed by refilling the vessel, and re-boiling the fresh supply of water.