upplies the amphitheatre and city of Nimens. The bridge of Alcantara, upon the Tagus, is still a work fit to raise in us a great idea of the Roman magnificence: it is six hundred and seventy feet long. and contains six arches, each of which measure above a hundred feet from one pier to the other; and its height from the surface of the water is two hundred feet. The broken remains of Trajan's bridge over the Danube, are still to be seen; which had twenty piers of free stone, some of which are still standing, a hun. dred and fifty feet high, sixty in circumference, and distant one from another an hundred and seventy. I should never end, were I to enumerate all the admirable monuments left us by the anci ents; the slight sketch here given of them, will more than suffice to answer my purpose. As to the ornaments and conveniencies of their buildings, among many I shall mention but one, that of their using glass in their windows, and in the inside of their apartments, just in the same manner as we do. Seneca and Pliny inform us, that they decorated their rooms with glasses; and do not we the same in the use of mirrors and pier glasses? But what will more shock the general prejudices is, that they should know how to glaze their windows, so as to enjoy the benefit of light, without being injured by the air; yet this they did very early. Before they discovered this manner of applying glass, which is so delightful and so commodious, the rich made use of transparent stones in their windows such as the agat, the alabaster, the phengites, the talcum, &c. whilst the poor were under a necessity of being exposed to all the severities of wind and weather.

If we admire the ancients in those monuments which remain to us of the greatness of their undertakings, we shall have no less reason for wonder in contemplating the dexterity and skill of their artists, in works of a quite different kind. Their works in minia. ture are well deserving of notice. Archytas, who was contempo rary with Plato, is famous in antiquity, for the artful structure of his wooden pidgeon, which imitated the flight and motions of a living one. Cicero, according to Pliny's report, saw the whole Iliad of Homer, written in so fine a character that it could be contained in a nutshell: and Ælian speaks of one Myrmecides a Milesian, and of Callicrates a Lacedemonian, the first of whom made an ivory chariot, so small and so delicately framed, that a fly with its wiing could at the same time cover it, and a little ivory ship of the same dimensions; the second formed ants and other little ani

mals out of ivory, which were so extremely small, that their com. ponent parts were scarcely to be distinguished. He says also in the same place, that one of those artists wrote a distitch in golden letters, which he enclosed in the rind of a grain of corn.

It is natural here to enquire, whether in such undertakings as our best artists cannot accomplish without the assistance of microscopes, the ancients had no such aid; and the result of this research will be that they had several ways of helping the sight, of strengthening it, and of magnifying small objects. Jamblichus says of Pythagoras, that he applied himself to find out instruments as efficacious to aid the hearing, as a ruler, or a square, or even optic glasses, dorpa, were to the sight. Plutarch speaks of mathematical instruments which Archimedes made use of, to manifest to the eye the large. ness of the sun; which may be meant of Telescopes. Aulus Gellius having spoken of mirrors that multiplied objects, makes mention of those which inverted them; and these of course, must be concave or convex glasses. Pliny says, that in his time, artificers made use of emeralds to assist their sight, in works that require a nice eye; and to prevent us from thinking that it was on account of its green colour only that he had recourse to it, he adds, that they were made concave, the better to collect the visual rays; and that Nero made use of them in viewing the combats of the Gladiators. In short, Seneca is very full and clear upon this head, when he says, that the smallest characters in writing, even such as almost intirely escape the naked eye, may easily be brought to view by means of a little glass ball, filled with water, which had all the effect of a microscope, in rendering them large and clear; and indeed this was the very sort of microscope that Mr. Gray made use of in his observations. To all this add the burning glasses made mention of before, which were in reality magnifying glasses; nor could this property of them remain unobserved.

[Dutens.

SECTION 11.

Comparative View of the Architecture of different Ages.

THAT architecture is of great antiquity is undeniable. But the primitive buildings were very different from the specimens of architecture we now meet with in civilized countries. In those mild climates which seem to have been the first inhabited parts of

this globe, mankind stood more in need of shade from the sun than of shelter from the inclemency of the weather. A very small addition to the shade of the woods, served them for a dwelling. Sticks laid across from tree to tree, and covered with brushwood and leaves, formed the first houses in those delightful regions. As population and the arts improved, these huts were gradually refined into commodious dwellings. The materials were the same, but more artfully put together. At last agriculture led the inhabitants out of the woods into the open country. The connection between the inhabitant and the soil became more constant and more interesting. The wish to preserve this connection was natural, and fixed estab. lishments followed of course. Durable buildings were more desir. able than those temporary and perishable cottages, stone was substituted for timber. But as these improved habitations were gra. dual refinements on the primitive hut, traces of its construction remained, even when the choice of more durable materials made it in some measure inconvenient. Thus it happens that the trunks of trees, upright, represent columns; the girts or bands, which serve to keep the trunks from bursting, express bases and capi. tals; and the summers, laid across, gave a hint of entablatures; as the coverings, ending in points, did of pediments.

We shall not enter minutely into a history of the progress of ar, chitecture; but shall shew that the above view of ornamental archi. tecture will go far in accounting for some of the more general differences of national style which may be observed in different parts of the world. The Greeks borrowed many of their arts from their Asiatic neighbours, who had cultivated them long before. It is highly probable that architecture travelled from Persia into Greece. In the ruins of Shushan, Persepolis, or Tehiminar, are to be seen the first models of every thing that distinguishes the Grecian archi. tecture. There is no doubt, we suppose, among the learned, as to the great priority of these great monuments to any thing that remains in Greece; especially if we take into account the tombs of the mountains, which have every appearance of greater antiquity than the remains of Persepolis. In those tombs we see the whole ordonnance of column and entablature, just as they began to de. viate from their first and necessary forms in the wooden buildings. We have the architrave, frize, and corniche; the far-projecting mutules of the Tuscan and Doric orders; the modillions no less distinct; the rudiments of the Ionic capital; the Corinthian capi

tal in perfection, pointing out the very origin of this ornament, viz. a number of long graceful leaves tied round the head of the column with a fillet; a custom which we know was common in their temples and banqueting rooms. Where the distance between the columns is great, so that each had to support a weight too great for one tree, we see the columns clustered or fluted, &c. In short, we see every thing of the Grecian architecture, but the sloped roof or pediment; a thing not wanted in a country where it hardly ever rains. In the stone-buildings of the Greeks, the roofs were imitations of the wooden ones; hence the lintels, flying corniches, ceilings in compartments, &c.

The ancient Egyptian architecture seems to be a refinement on the hut built of clay, or unburnt bricks mixed with straw: every thing is massive, clumsy, and timid; small intercolumniations, and hardly any projections.

The Arabian architecture seem a refinement on the tent. A mosque is like a little camp, consisting of a number of little bell tents, stuck close together round a great one. A caravansary is a court surrounded by a row of such tents, each having its own dome. The Greek church of St. Sophia at Constantinople has imitated this in some degree; and the copies from it, which have been multiplied in Russia as the sacred form of a Christian church, have adhered to the original model of clustered tents in the strictest manner. We are sometimes disposed to think that the painted glass (a fashion brought from the east) was an imitation of the painted hangings of the Arabs.

The Chinese architecture is an evident imitation of a wooden building. Sir George Staunton says, that the singular form of their roofs is a professed imitation of the cover of a square tent.

The great incorporation of architects who built most of the ca. thedrals of Europe departed entirely from the styles of ancient Greece and Rome, and introduced another in which arcades made the principal part. Not finding in every place quarries from which blocks could be raised, in abundance, of sufficient size for forming the far-projecting corniches of the Greek orders, they relinquished those proportions, and adopted a style of ornament which required no such projections: and having substituted arches for the hori zontal architrave or lintel, they were able to erect buildings of vast extent with spacious openings, and all this with very small pieces

of stone. The form which had been adopted for a Christian tem. ple occasioned many intersections of vaultings, and multiplied the arches exceedingly. Constant practice afforded opportunities of giving all possible varieties of these intersections, and taught the art of balancing arch against arch in every variety of situation. In a little time arches became their principal ornament, and a wall or ceiling was not thought properly decorated till it was filled full of mock arches, crossing and butting on each other in every direction. In this process in their ceilings these architects found that the projecting mouldings, which we now call the Gothic tracery, formed the chief support of the roofs. The plane surfaces included between those ribs were commonly vaulted with very small stones, seldom excceding six or eight inches in thickness. This tracery, therefore, was not a random ornament. Every rib had a position and direction that was not only proper, but even necessary. Ha. bituated to this scientific arrangement of the mouldings, they did not deviate from it when they ornamented a smooth surface with mock arches; and in none of the highly ornamented ancient buildings shall we find any false positions. This is far from being the case in most of the modern imitations of this species of architecture.

We call the middle ages rude and barbarous, and give to their architecture the appellation Gothic; but there was surely much knowledge in those who could execute such magnificent and difficult works. The more appropriate terms, we conceive, would be those of Saxon and Norman architecture, at least, so far as relates to such works in Britain; giving the first term to that kind distin. guished by the circular arch, and the latter to that distinguished by the pointed arch: for under the guidance of these respective nations did each kind principally display its grandeur and peculiarities.

The architects of whom we now speak do not appear to have studied the theory of equlibrated arches: but, for a long period, they adopted an arch which was very strong, and permitted considerable irregularities of pressure; we mean, the pointed arch. The very deep mouldings with which it was ornamented, made the arch-stones very long in proportion to the span of the arch. They had, however, with great care, studied the mutual dependence of arches on each other; and they contrived to make every invention for this purpose become an ornament, so that the eye required it as a