era, and was eminently distinguished for his learning and for the number and ingenuity of his mechanical inventions, is the first who gives any account of the application of the vapour of water. In his work, entitled Spiritalia, or Pneumatica, he describes, amongst many others, two machines which operate by the force of steam. The first (figure 1) is a caldron or vase C, containing boiling water, with a pipe P reaching nearly to its bottom. As the steam accumulates in the top of the vessel, it presses on the surface of the water, and will force it in a continued jet through the pipe, till the whole is ejected or converted into steam. A fountain may thus be formed capable of supporting the ball B.

FIG. II.

B

B

The second (fig. 2) consists of a similar vessel C, which is closely covered with a lid, having two pipes A A, which after rising vertically for a short distance, are bent towards each other, and serve as pivots to support the hollow arms B B, in which are openings corresponding to those in the pipes. These arms are furnished with two open tubes, and placed diametrically opposite to each other, and bent at their extremities in contrary directions, and at right angles to the axis of the globe. The stream from the water in the vessel rises through the pipes into the globe, and issuing through the tubes causes the globe

to revolve, in the same manner as water produces the rotary motion of Barker's mill. Though this apparatus is described as a mere philosophical toy, and not the slightest hint is given that the invention was capable of any useful application; it is curious, as being the earliest instance we are acquainted with, of the employment of steam to produce motion; thus conferring on Hero the honour of having invented and constructed the first steam engine. Hero also expressly ascribes the sounds which issued from the statue of Memnon to the action of steam. If this be correct, we have an instance of the application of steam to (we will not say a useful, but to) a specific purpose, as early as 1600 years before Christ. But we are of opinion with Professor Renwick, "that this is rather an ingenious explanation by the philosopher himself, of the mode in which he could have effected the same object, than an account of what was really performed by the Egyptian priests."

The description of these machines sufficiently establishes the fact, that the ancients were acquainted with both the expansive and impulsive force of steam. Our information from other sources is exceedingly scanty and imperfect, and is chiefly incidental. The Oelipile appears to be the only instrument used by them to display its power, and that was applied to only one object to excite combustion. How it was used for that purpose is not explained, and, as steam itself will not support combustion, remains a matter of conjecture. Vitruvius, in his treatise on Architecture, Lib. 1. Cap. VI. refers to the clipile as an illustration of the causes of winds.

Fig. 3 is a representation of this instrument; which consists of merely a globe or other hollow vessel A, containing a smal quantity of water, and having spouts or tubes, B B. The vessel being placed over a fire, the water is converted into steam and will issue forcibly from the tubes. If the clipile be placed on wheels, it will recoil by the reaction of the steam, as it escapes; and a rotary motion may be obtained by employing two tubes, as in the machine of Hero. In this form it is called the whirling œlipile.

FIG. III.

B

We find no further notice of steam being applied to any purpose, either of use or amusement, till after the revival of learning; and the earliest modern writers we meet with who speak of its mechanical properties, are Cardan and Mathesius. The latter, in a volume of sermons, published about 1760-'63, hints at the possibility of constructing an apparatus similar in its operation and properties to the modern steam engine, and “displayed almost as much ingenuity in contriving to introduce so untoward a subject into a sermon as would be required to invent the machine itself, and which he gives as an illustration of what mighty effects could be produced by the volcanic force of a little imprisoned vapour."

age

Cardan, who (to quote Renwick) "united all the learning of his to even more than all its superstition," is the first among the modern writers who mentions the clipiles, and seems to have been acquainted, not only with the expansive force of steam, but also the fact that a vacuum could be produced by its condensation. About thirty years after this period, the “whirling œlipile" is proposed to supersede the turnspit dog in the honorable discharge of his culinary duties. Whether this substitution of machinery for manual labour was prevented by remonstrance or petition on the part of the domestics whom it would so cruelly turn out of employment, is not on record; but, from one of the reasons urged for its adoption, it appears that in this, as in other cases, the bad conduct and dereliction from honesty of some of these useful laborers, endangered the subsistence of the whole. The projector states that his machine

"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."

The next we find worthy of notice is Baptista Porta, a Neapolitan. He describes his apparatus in an Italian translation of Hero's work, published 1606. It is remarkable as being the first in which the steam is applied to force up cold water from a separate vessel, instead of driving up the hot water, from which it is produced. The boiler A (fig. 4) has a neck or tube B, through which the steam passes to the upper part of the close cistern C, and, passing on the surface of the water it contains, forces it up the pipe or syphon D. The contrivance in this respect is similar to, and would seem to be the germ of, that

of the Marquis of Worcester, from which it differs but little, except in the extent of its power.

FIG. V.

A

In 1615, Solomon De Caus, a native of Normandy, eminent as an engineer and mathematician, published a work on Moving Forces and Machines, in which is to be found the following contrivance for applying the expansive force of steam. He says: "Let there be a globe A, (fig. 5) having a valve B to introduce water, and a tube C soldered into the upper part of the ball, and descending nearly to the bottom. After having filled the ball with water, and well closed the valve, place it on the fire; then the heat acting on the ball will cause the water to ascend through the tube." This apparatus (on which M. Arago claims for the French the honor of inventing the steam engine) is not only inferior to that of Porta, but had been anticipated in all but the valve by Hero.

De Caus was also acquainted with the fact that steam could be condensed into its own weight of water; but he appears to have known no mode of applying this property to aid the effect of his fountain.

The machine of Giovanni Brancas, an eminent Italian mathematician, who lived at Rome in the commencement of the seventeenth century, next claims our attention, being the first in which the power of steam was proposed to be used for any