STATUE OF MEMNON.

A precocious germ, without a tendency to progression, is characteristic of eastern art. Nations,

Hero, and found in his "Pneumatica." The subject has exercised the ingenuity of many writers. Among the moderns, Solomon Decaus gives a good diagram of a combination for this purpose: he places the figure on a well-closed base, or pedestal, exposed to the sun, and containing water. An organ pipe proceeds from the interior of the pedestal to the mouth of the statue. p. 23. Raisons des Forces Mouvantes, Paris, 1629. Kircher displays his usual ingenuity in discussing this topic. His first scheme would produce sounds according with the description of Philostratus. The water is placed in the lower division of the cavity of the pedestal, in a situation to be acted on by the sunbeams. A pipe forms a communication with the upper division, which contains a wheel with vanes, and which is also furnished with tappets; a series of harp wires are likewise placed in the upper ipart, which are so arranged, that when the vapour issues from the lower into the upper division of the pedestal, through the pipe, it strikes on the vanes; this gives motion to the wheel, and the tappets, as they revolve, are successively brought into contact with the wires. Edipus Ægyptiacus, cap. Mechanica Egyptorum.

His second scheme is an extension of Decaus's. The sunbeams are concentrated by a series of mirrors upon that part in which the water is concealed. He thinks five reflectors would do the business; but 100, or 1,000 placed in this manner,-" certum est calorem tam intensum fore ut omnia adurere possit et in cineros redigere." p. 886. Ars Magna Lucis et Umbra, Romæ, 1646.

The statue of Serapis moved its eyes and lips at the rising of the sun; and the bird of Memnon flapped his wings, and was accommodated with a voice, it is said, by means of air rarefied by the sun's heat. pp. 327, 328. Edip. Egypt.

Cribellus, adopting nearly the same arrangement as Kircher, wonderfully extends his idea; he displays a formidable array of wheels, pinions, cranks, and other things to give motion to a bellows for supplying wind to an organ almost large enough for the cathedral of St. Peter: the tones of numerous harpstrings are added to make up a harmony. He concentrates the sunbeams by "parabolas, hyperbolas, ellipses," and other figures, by which, he says, Conos even melted metals; and he doubts not but that the aromatics, (or resins,) which he places along with the water within the pedestal, would be easily inflamed. The rays "derigerent ad vasum et aërem rarefacerent, et aromatæ incenderant, et aquas cogerent subsilire, cum autem ex dictis minima vis sufficiat. Non est quod hinc detremen

PTOLEMY PHILADELPHUS.

almost at the instant of the foundation of their communities, are seen in possession of discoveries, and expert at their application, which are usually considered to be the portion of the most polished societies only, and the fruit of a long career in refinement. Unlike the European races, incessant in their attempts to enlarge the circle of their knowledge and improvement, the Orientals passively remained the willing slaves of first impressions, seldom exerting a power to give those inventions they had so admirably drawn into being, that perfection and extension of which they were so obviously susceptible.

But when, aided by the indolent effeminacy into which the successors of Sesostris had fallen, the enterprise of the Macedonians was crowned by the establishment of their rule over Egypt, the restless energy of these warriors being attempered by the monotonous refinement of its ancient inhabitants, a new and beneficial impulse was imparted to both. During the splendid dominion of her Grecian kings, the arts and sciences of Egypt reached a high degree of excellence; and under one of the Ptolemies, surnamed Philadelphus, and his successors Euergetes I. and II., the court of Alexandria was resorted to as a school of philosophy by the learned and ingenious of many countries. Mechanics, and the kindred sciences, were there held in great esteem; and eminence in

tum aliquod timeamus." He doubts the possibility of Kircher's getting as much vapour as he expected, and thinks his apparatus would give but weak Memnonic groans; but in his own "ut vulcaniam et æoliam obtineremus efficaciorem cujus vi noster Memnon non tenues philomelæ instar gracilescat in modus, sed tonare, effulminare cum pericle possit et mundi parem ditionis amplitudinem, ne dum exiguam Græciam orando valeat permiscere." p. 8. Machinosa Miracula Memnonis, Romæ, 1656

8

HERO OF ALEXANDRIA.

their acquirement being opened as a path to personal honour, the boundaries of knowledge were extended, through the exertions of its professors to deserve the countenance of their illustrious patrons.

Among the men of genius who enjoyed the patronage of these munificent princes, one of the most distinguished was Hero the elder, the son of a Greek who had settled at Alexandria. At an early age, the strong bent of his mind towards mechanical pursuits attracted the notice of the celebrated Ctesibius; and the after friendship of that philosopher was the reward of his application and merit. Under his guidance, Hero aspired to celebrity as a follower of Democritus in philosophy; and some beautiful discoveries in mechanics recompensed the study of a long life, assiduously devoted to their cultivation.

The experience of a later time, it is true, has been triumphantly urged as ranking Hero's among other ancient inventions, which may serve as curiosities to amuse our leisure, rather than objects inviting study by a display of useful ingenuity. A candid estimate of a mechanical effort may not, however, be made, by marking its absolute height above every production of a similar kind, but by measuring its elevation above those only placed in its peculiar region. An eminence, conspicuous among the gentle undulations of a champaign country, would be altogether unobserved at the base of a range of mountains. Yet, nevertheless, tried by the high standard of even modern attainment, several of the machines described by Hero* may be compared with the most

Gli artificiose et curiosi moti Spiritalia de Herone, tradotti de M. Gio. Bapt. Aleotti. Bologna, 1547, reprinted Ferrara, 1589. The figures are beautiful, and were copied from the Greek

SPIRITALIA.

useful, or the most ingenious, of those which have been appealed to as proud monuments, placing our own age at an immense distance beyond every other in mechanical invention. The fountain for raising water by the compression of air remains as he left it. The mode of forming a vacuum, by sucking the air from a vessel, and producing a blast by a fall of water, are to be found in the Spiritalia;" and the construction of the fireengine was first learnt from his descriptions.

66

And if the numerous devices in his" Pneumatica" do not all possess the same originality and practical merit, this inequality, objected to as a blemish, will be found to have arisen from a circumstance which adds a grace even to his genius-from his enlightened mind appreciating with a generous liberality the value of the labours of others. Hero, in his introduction, professes to have made himself acquainted with the works of his prede

MS. All the subsequent translators, except Bapt. Porta, (and his diagrams are in a very vulgar taste,) have copied Aleotti's illustrations. The Bologna edition is very rare.

Heronis Alexandrini Spiritalium liber a Federico Commandino ex Græco in Latinum conversus, 1575. Printed after Commandine's death, with the addition of Aleotti's four theorems on automata, rendered into Latin: this edition was reprinted in an elegant style, at Amsterdam, 1680. Spiritali de Herone Alessandrino ridotti in lingua volgare da Alessandro Giorgi. Urbino, 1592. De Herone Alessandrino de gli automati overo machine moventi libri due: tradotto dal Græco Bernardino Baldi. Venetia, 1601. I Tri Libri de' Spiritali de Giovan Batista della Porta, Napolitano, cive d'inalzar acqua per forza dell aria. Napoli, 1606. In the collection, "Veteres Mathematici," Paris, 1693, folio, the Greek text of the Spiritalia is given with a new translation into the Latin, accompanied with Aleotti's theorems on automata. This is a good edition, and common.

Schmidt's Vitam Heronis, Helmstadt, 1714, contains some biographical notices from Baldi and others, and a classification and a summary of his inventions: see also Frobisii's Rudimenta Biographia Mathematica. Leipsig, 1757.

cessors and contemporaries, to have greatly admired their simple ingenuity, and to have been unwilling that such fine inventions should be overlooked or perish; he described them, therefore, that they might be better understood; and, by placing them among his own contrivances, he not only ensured their being more widely known, but that the knowledge of them would descend to posterity. Having done this, his aim appears to have been accomplished; for, apparently, considering them but as brilliant first thoughts only, they were flung together, and left in a kind of affluent neglect, to be arranged or applied by those who had more leisure and less exuberance of original conception.

In thirteen problems, Hero operates by the action of heat on air or water. In two, the doors of a temple are opened and shut by means of the rarefaction of air, produced by its coming into contact with the heated hearth of an altar; in another, water or wine is raised by the same means, and made to flow on the sacrifice, to assist in its combustion; this is combined with the hissing of a dragon in a fourth; and a rotary motion is imparted to a small stage, on which automata are placed in a fifth. In some of these, however, from the construction of the apparatus, steam of low temperature would be produced, and assist in the action. But throughout, it is not quite obvious that Hero had a notion of the distinction between the heated air and the vapour; or rather, he considered that the vapour owed its power to the heated air with which it was combined or mixed. He describes three modes in which steam is used directly as a mechanical power: to raise water by its elasticity; to elevate a weight by its expansive power; and to produce a rotary motion by its reaction on the atmosphere.