to treat equally of the past and the present; and his geographical descriptions are introduced by an accurate history of the particular country under view, while, at the same time, they are enriched by observations on the phenomena of nature, as exhibited in different climates and regions, extending to the determination of the maximum of atmospheric heat under the tropics and the equator, the comparison of the longer or shorter passages of the sun across the zenith, the various influences which produce changes in the earth's surface, the Archimidean doctrine of the general level of the sea, the origin and character of seas, rivers, and currents, the operation of volcanoes and earthquakes on the earth's crust, and the nature of petrifactions and marine impressions. The religion and manners, the social habits, the institutions, superstitions, and traditional customs of each tribe or people are separately delineated; and, by marking their diversity of physique, an attempt is made to indicate the primary types of race. The author's profound research is evinced by a prophetic hypothesis, based on a supposed prolongation of the Tauric chain, that between the eastern shores of Asia and the west of Europe, near the parallel of Athens, which

traverses the Atlantic Ocean, there may be, in addition to the world we inhabit, one or more other worlds inhabited by races different from ourselves.' 35 Here we have the first conjecture of a western continent.

The petrified fish and shells observed Strabo in different parts of the earth had not escaped the notice of earlier travellers; and, from a very remote period, they were recognised as indubitable evidence of great terrestrial convulsions. So far back as B.C. 880, we trace the faint outline of a geological theory in the Ordinances of Menu, the great teacher of the Hindoos. Menu, after stating that the past has been a succession of periods, each comprising an infinite number of ages, affirms that there are creations also and destructions of worlds innumerable.' 36 Herodotus records the opinion of the Egyptian priests that their native country, as far as the mountains beyond Memphis, was originally a bay of the sea;37 and adds from his own observation, I I myself give credit to these things concerning Egypt, and am myself convinced of their truth, when I see that Egypt projects beyond

35 Lib. i. and ii.

36 Sir W. Jones's 'Institutes of Hindoo Law, or, the Ordinances of Menu.' 37 Herod. ii. 10.

the adjacent land; that shells are found on the mountains; that a saline humour forms on the surface even to corrode the pyramids; and that this mountain which is above Memphis is the only one one in Egypt that abounds in sand.' 38 Such a passage claims to be quoted, as it shows how closely the configuration and constituent structure of the earth were now observed, B.c. 455. Plato 39 has preserved to us the Egyptian myth, taught by the priests, that the world was subject to periodic deluges and conflagrations, entailed upon it by the wickedness of its inhabitants; and, according to Cassander, these visitations occurred at the conclusion of a great cycle of 360,000 years, when the sun, moon, and planets simultaneously completed their revolutions in the same sign of the zodiac. The world was said to be reproduced from an egg, by a spiritual Being, uniting both sexes; and, as the same process is adopted by Menu, the myth may possibly veil some tradition of Noah and the Deluge, so obscured by time as to be unintelligible.

Pythagoras, who visited both Egypt and India, caught the speculative, while he repudiated the fabulous tenets of primeval

38 Lib. ii. 12.

39 Pl. Ti.

geology. His structural theory of the earth is coloured by his doctrine of the transmigration of souls, which may, in the first place, have been deduced, either by himself or his Hindoo teachers, from the phenomena exhibited by the operations of nature. He taught 40 that matter was imperishable, though, by an immutable universal law, it was ever in motion, ever changing, taking some new form, posture, quality, or condition. Transmutation was effected by particles, while the mass appeared to be always the same. Thus the sea, as was proved by shells and other marine remains found in elevated plains and on the summits of mountains, was converted into dry land, and, on the other hand, land sank beneath the waves; swamps were drained by streams, which, in their course, wore away hills and excavated valleys, depositing the drift in the bed of the sea, where it formed peninsulas or islands. Other changes were accomplished by volcanoes and earthquakes, which absorbed lakes, upheaved mountains, and opened thermal springs, endued with different mineral and medicinal qualities. All these facts are based on observed phenomena; they were more firmly established

40 Ovid's Met.' xv.

by the investigations of Aristotle;11 and, recovered from the gulf of the dark ages, they now form the basis of modern geology.

Strabo has embodied in his Geography most of the geological principles of Pythagoras, as facts confirmed by personal observation; but his celebrated work, though composed at the beginning of the Christian era, was but little read by the ancients. Even a century later, geographical science was chiefly known from the work of Ptolemy Claudius, who flourished in the reigns of Adrian and Antoninus Pius A.D. 120-160; and this continued to hold the highest place for many ages. It occupies in geography the same relation to the more elaborate writings of Strabo, that, in modern times, those of Linnæus present in natural history to the researches of Buffon; and, while naked in description, astonishes us by its methodical classification, its apt nomenclature, its accuracy, expansion, and grasp. Still it was more an itinerary than a geography, a massive and compact scaffolding rather than the edifice itself; and its geographical notices are like the inscriptions on an ancient monument, giving a history in an epigram. Though void 41 Meteorics, c. 12.