3. The publication of the fact that water may be raised by the force of steam, coming from boiling water, and confined: and construction and description of an apparatus by which this would be effected on the small scale.

4. The publication of the fact that if a space to which water has free access be filled with steam, and the steam be then condensed, the water will rush into that space.

5. The proposal to apply the power of steam as in No. 3. (though in a much less perfect mode) to use for raising water on the large scale.*

6. The suggestions to procure a power or force by the pressure of the air on a piston in a cylinder, a vacuum being made below the piston; and to raise the piston by gunpowder. j

7. The directing public attention forcibly to the application of steam for raising water, and actually raising large masses of water great heights by steam power, with obscure hints as to the plan.†

PORTA, 1606.

PORTA, 1606.

DE CAUS, 1615.

GUERICKE, 1672. HAUTEFEUILLE, 1678.

WORCESTER, 1663.
MORLAND, 1683.

property, is an essential element in the application of steam as a moving force. It includes No. 1-but is something additional. No. 1 does not include it-may exist without it; as in RIVAULT'S Experiment, &c. *The apparatus of DE CAUS, containing nothing beyond PORTA's— indeed, inferior to it in a most important point,-is not mentioned. The idea of use on the large scale is all that is DE CAUS'S.

Few, I suppose, will dispute, that it lends some aid to the progress

8. Suggesting to procure a vacuum below a piston by boiling water under it, and then condensing the steam, instead of by the air-pump; the air's pressure then pushing down the piston.*

9. Planning, constructing, and bringing into operation an Engine, to raise water great heights, partly by the ascent of the liquid into a vacuum formed by condensing steam, and partly by the force of the steam directly applied; and requiring a great number of different parts and different principles, ingeniously adjusted-in short, the first steam-engine that ever did work.

any

10. The planning, constructing, and bringing into operation an efficient engine, requiring a great number of different parts, ingeniously adjusted to work a common pump-by means of a CYLINDER, with a PISTON moved by atmospheric pressure, a vacuum being procured below the piston by condensing steam, and the motion being transmitted by a BEAM.

PAPIN, 1690.

SAVERY, 1698.

NEWCOMEN and
CAWLEY, 1705.

of an invention, to have it proclaimed as possible and done, even though the manner of doing it be not explained precisely.

Besides this, there is some reason to believe that PAPIN also raised the piston by the force of the steam coming from the water boiling under it.

11. The planning, constructing, and bringing into operation a steam

engine for raising water, embracing JAMES WATT, several important new inventions, and

far more efficient and economical than Newcomen's.

12. The planning, constructing, and bringing into operation a steamengine, with several new inventions, and some new applications, and adapted for the great end of impelling machinery.

1769.

JAMES WATT,
1784.

178. When steam about or near the ordinary pressure of the atmosphere is used, the engine is called a low pressure, or condensing engine. It can have no motive power if resisted by the air's pressure. To give such steam an impelling force, the space towards which it acts must be a vacuum, or nearly so. The vacuum being procured by the condensation of steam-hence the name

66

condensing engine." Where there is not a vacuum made, the steam having to balance the air's pressure, besides exerting a motive power, must be of a very high pressure. Such engines are called high pressure, or non-condensing.

SECTION I.

EOLIPILE OF HERO.-ORGAN OF GERBERT.-GARAY'S STEAM BOAT.-FOUNTAIN OF PORTA AND KIRCHER.-RIVAULT'S BOMB.-ENGINES OF DE CAUS, BRANCA, WORCESTER, AND MORLAND.-PAPIN'S FIRST ENGINE.-130 B.C. TO 1690 A.D.

179. In many ancient records we find faint glimmerings of a knowledge of the power of steam. Earthquakes and volcanic eruptions were attributed to the sudden vaporization of water; and it is related of an architect of the time of Justinian, that by means of steampipes issuing from a boiler, and opening in the partition between his own house and that of a neighbour who had given him some offence, he produced artificial earthquakes in his neighbour's mansion, and succeeded in creating great alarm, and rendering him very uncomfortable. The sounds emitted at sunrise from the famous statue of Memnon, in Egypt, have been attributed to the movement of the vapour raised by the action of the sun's rays from water concealed within and the sudden escape of pent-up steam was said to have been employed by the Teutonic priests as a means of awing their followers, by loud explosions accompanied by clouds of vapour made to issue from the heads of their images.

ÆOLIPILE.-B.C. 130.

180. The first instance on record of the force of steam being applied to produce continuous motion, is that of the Eolipile, a philosophical toy, described in the writings of Hero of Alexandria, who flourished

during the reign of Ptolemy Philadelphus, about 130 years before the birth of Christ. This writer was distinguished for his mechanical knowledge. Besides the Æolipile, described in the next paragraph, he also was acquainted with the forcing-pump for raising water (the invention of Ctesibius); the beautiful contrivance for an artificial fountain, still called Hero's fountain; a machine for producing a rotatory motion by a jet of heated air; and many other curious mechanical inventions.* The following cut will explain the action of the Æolipile.

181. The boiler, a, is covered with a lid, into one side of which the pipe b is inserted, which, after rising vertically, is bent at right

angles, and transmits the steam into the globe g, the globe revolving round the arm d. From the other side of the boiler rises a support, c, which is bent at right angles, and terminates in a pivot, on which the globe revolves. The globe has two small tubes issuing from it, opposite to each other, and at right angles to the line of the bent

FIG. 8.

parts, de. These tubes are bent close to their open ends, m n, at right angles, and in opposite directions;

Many of which, there is reason to believe, were used by the ancient priests to awe the people by exhibiting apparently miraculous power, as causing blood (in reality wine) to flow from figures or statues, &c.