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As before stated in our introductory remarks, the ancients are known to have had an acquaintance with the utility of the power of steam and heated air, and had devised certain contrivances in which this power was developed These contrivances were, as may be supposed, applied to no purpose of utility, but served more as the means of exciting the wonder of the populace, as the miraculous production of their priesthood, and as forming part of the mysteries of their worship. Thus, one of the contrivances of the well-known Hero of Alexandria, who flourished 130 years before Christ,—the first personage who figures in the stereotyped history of the steam-engine,—was for the purpose of causing wine to flow from the hands of images placed beside the altar; and was effected as follows: “A steam-tight vessel or vase containing wine is placed within each image, the altar being made hollow, and partially filled with water; bent tubes reaching from the space in the altar above the water to the space in the vases above the wine; and other tubes are taken from the vases, below the level of the wine, to the hands of the images. Matters being thus prepared, when you are about to sacrifice," says Hero, you must pour into the tubes a few drops lest they should be injured by heat, and attend to every joint lest it leak; and so the heat of the fire mingling with the water will pass in an aërial state through these tubes to the vases, and pressing on the wine, make it pass through the bent syphons until, as it flows from the hands of the living creatures, they will appear to sacrifice, as the altar continues to burn. In another contrivance, the force of the vapour of water was perhaps more obviously shown. In fig. 1, a caldron or vase a has a pipe c fitted to it, terminated by a small cup d. On the caldron being partially filled with water, and fire applied beneath it, the steam, issuing from the jet with considerable velocity, raises and supports the ball e so long as the steam is kept up. But the principal contrivance

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for which Hero is famed, and one which in itself comprises nearly all the requisites of a complete prime-mover, is that known as the “ Æloipile."

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This invention is, moreover, all the more remarkable and worthy of notice, from the fact that in recent times it has been introduced into practice as an efficient and economical steam-engine. Fig. 2 will explain the arrangement of its parts, and its operations. Let a be a caldron or vessel partially filled with water and placed on a fire; two pipes b'b.communicate with the interior of this, and are bent at the top at right angles; a hollow ball c revolves on the arms bb, and has two pipes e d placed at the opposite ends of its diameter; the ends of these pipes are made up, but apertures are made in the opposite sides of each. The steam rising through the tubes bb, passing into the hollow ball c, is ejected through the apertures in ed; the reaction of the opposite jets of steam on the surrounding air causes the globe c to rotate with rapidity on its axis, “as if it were animated from

within by a living spirit.” In fig. 3 the relative arrangements of the jets from the tubes bc is shewn; the globe a revolving in the direction of the arrows. In these contrivances the properties of steam expansion and contraction are made known. It is somewhat remarkable — as taking the era of the introduction of steam and heated air as a motive-power much further back than is generally supposed — that Hero states that he made himself acquainted with the labours of his predecessors and contemporaries in connexion

with pneumatical contrivances, and that many fig. 3.

of those which he describes in his Spiritalia

seu Pneumatica were not of his own invention; thus inducing the belief that this power was known for ages previously, although its operation, doubtless, was only known to the priests. All authorities agree in thinking that the knowledge of the power of steam was more widely disseminated than is generally believed. That this power was applied chiefly, if not exclusively, by the priesthood, for the purpose of exciting a belief in their worshippers of the supernatural intervention


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which at times they could command, is also pretty conclusively ascertained. What schoolboy has not read of the mysterious Memnon, whose mystic utterance of sounds has even yet, in these utilitarian days, tinct and mysterious interest, for no myth of the most graceful mythology is so significant as its story.” Yet the “ seven mystic vowels, which are the

very heart of mysteries to us,” are said to have been produced by some of those pneumatic contrivauces which Hero describes. “When the secrets of the waning faith,” says an elegant writer, “ were revealed by the votaries of a rival belief, the celestial harmony was then said to be produced by vapour, rising from water concealed in a cavity of the statue, being made to pass through a tube having a small orifice fashioned in a manner similar to that of an organ. As long as the fluid was heated by the rays of the sun, mysterious sounds were heard by the assembled worshippers, which died gradually away as the solar influence was withdrawn from the gigantic idol."

At this stage of our progress an inquiry will naturally arise—how is it, that with all the ingenuity of the ancients, so fertile and so suggestive a power should have been allowed to remain developed only in the devices of priestcraft, and not adapted to the purposes of a more varied and general utility? The cause of this apparent neglect may be traced to the same sources which influenced the obscurity which has hid from later times the arts of antiquity. Another cause may be in the following, so well put by an able writer : “ The ancient philosophers esteemed it an essential part of learning, to be able to conceal their knowledge from the uninitiated. And a consequence of their opinion that its dignity was lessened by its being shared with common minds, was their considering the introduction of mechanical subjects into the regions of philosophy a degradation of its noble profession; somuch that ose very authors among them who were most eminent for their invention, and were willing by their own practice to manifest unto the world their artificial wonders, were notwithstanding, so infected by this blind superstition, as not to leave any thing in writing concerning the grounds and manner of these operations; by which means it is that posterity hath unhappily lost, not only the benefit of those particular discoveries, but also the proficiency of those arts in general. For when once learned men did forbid the reducing of them to vulgar use and vulgar experiment, others did thereupon refuse these studies, as being but empty and idle speculations; and the divine Plato would rather choose to deprive mankind of these useful and excellent inventions, than expose

the profession to the vulgar ignorant.” For centuries no attention seems to have been paid to the development of the power of steam; at least, history is a blank as to any notices thereof. Nevertheless, there are sufficient indications of the fact that its power was not altogether unobserved by philosophers and men attached to science; many in their writings hinting at the power to be derived from “ vapour,” and alluding confidently as to the capability of huge "engines" being forced into motion by the power of this agent. About the year 1121, according to William of Malmesbury," there were extant in a church at Rheims, as proofs of the knowledge of Gerbert, a public professor in the schools, a clock constructed on mechanical prin. ciples, and a hydraulic organ in which the air, escaping in a wonderful manner by the force of heated water, fills the cavity of the instrument, and the brazen pipes emit modulated tones through multifarious apertures.”



On the revival of learning throughout Europe, the dissemination of the writings of the ancient philosophers doubtless attracted attention to many of these contrivances. There is some probability attached to the supposition that the invention of Blasco de Garay, a sea-captain, introduced into notice in 1543, was founded upon or derived from one of these. His invention was designed for the propulsion of vessels, and appears to have been very efficient. Unfortunately no record is known to exist from which a knowledge of its parts can be ascertained. The following is the only account extant: “ Commissioners were appointed by the Emperor Charles the Fifth to test the invention at Barcelona, on the 17th June, 1543; and the result was, that a ship of 200 tons burden was propelled by the machine at a rate of three miles an hour.” The moving force was obtained from a boiler containing water, liable, as was said, to explosion; and paddle-wheels were the propelling power. Strange as it may appear, no further result was obtained from this trial, and the invention was lost sight of. Towards the close of the sixteenth century numerous expedients and mechanical contrivances for raising water were described in published works; these being based in principle on the contrivances detailed by Hero. Baptista Porta, in 1606, the well-known inventor of the camera-obscura, published a commentary on Hero's Pneumatica, in which he describes the

arrangement which is illustrated in fig. 4. Let a be a furnace, and b a small boiler or receptacle for the water to be heated; on the steam rising up the tube c, which is continued nearly up to the top of the air-tight box dd containing water, it presses on the surface of the water and forces it out through the tube


which is continued down nearly to the bottom of the box d d. This contrivance, although the author made no application of it for the purpose of raising water, is worthy of notice, if only for containing within itself the first known germ of an important distinction in steam-mechanism, namely, the adaptation of a separate vessel for containing the water to be raised, from that in which the steam or vapour was generated. Baptista Porta gives this arrangement merely as carried out in an experiment on the relative

bulks of water and steam.
Solomon de Caus, in

a work dated Heidelberg, in 1615, entitled, fig. 4.

Les Raisons des Forces mouvantes

avec diverses Machines tant utiles que plaisantes, amongst a variety of insignificant and fanciful theories and descriptions, gives an arrangement by which water is raised above its level.

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fig. 5.

In fig. 5 we give an illustration of De Caus' theorem on this point. Let a a be a ball of copper, having a pipe c by which to partially fill a a with water; another pipe bb reaching nearly to the bottom of the globe is also provided. On placing the globe on a fire and carefully stopping up the vent c, the steam or vapour pressing on the water in a a presses it up the tube 66. He also details the following illustration of the force of steam. “Take a ball of copper of one or two feet diameter and one inch thick, which being filled with water by a small hole, subsequently stopped by a peg so that neither air nor water can escape, it is certain that if the said ball be put over a great fire so that it may become very hot, it will cause so violent a compression that the ball will be shattered in pieces. It, however, required no experiment of this stamp to prove the force of steam; the ancients were by no means ignorant of this; indeed they went so far as to attribute earıhquakes to the force of pentup vapours derived from subterranean heat. And Alberti, in 1412, notices the effects of pent-up vapour -dreaded by the lime-burners of that period—on the stones: “ for when they come to be touched by the fire, and the store grows hot, it turns to vapour, and bursting the prison in which it is confined with a tremendous noise, blows up the whole kiln with a force altogether irresistible.”

M. Arago, in his anxiety, we presume, to claim the merit of the discovery of the invention of the steam-engine to a countryman of his own, attributes to De Caus a higher and more philosophical knowledge of the capabilities of steam than one would suppose he was in possession of, merely from his recital of the above experiment; and states that the ideas of the ancients respecting the force of steam had never reached any thing like the numerical appreciation realised by such experiments as those of De Caus. On this point we cannot do better than quote from the able treatise on the steam engine edited by John Bourne, Esq., C.E.: “We confess that we are at a loss to understand wherein this numerical appreciation can consist; for although De Caus or Rivault may have ascertained that steam will burst a cannon-ball or bomb, they never ascertained what sort of ball or bomb steam will not burst; so that they did not establish any limit to the power of steam, but only showed that it is capable of very powerful effects.”

In 1629, in a work published by Giovanni Branca, a description is given of a contrivance in which the force of steam was used as the actuating power. The water is heated in a vessel the upper part of which is fashioned like a head; from the lips of this a pipe or tube issues, which directs the steam against the vanes or boards of a wheel, made somewhat like an undershot wheel; this is made, by the impinging of the steam on the floats or vanes, to rotate rapidly. The wheel is placed horizontally, as b, fig. 6; in the vertical axis of this a small trundle is placed, which actuates the face-wheel d, and gives motion ultimately to stampers for compounding drugs in mortars. It is believed by some writers that this machine was actually in use for the above purpose; by others, however, this

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