a wall:  its extent 400 days’ journey from east to west, and half as much from north to south.  On the wall which bounded the earth, the firmament was supported.  The succession of day and night is occasioned by an immense mountain on the north of the earth, intercepting the light of the sun.  In order to account for the course of the rivers, he supposed that the plane of the earth declined from north to south:  hence the Euphrates, Tigris, &c. running to the south, were rapid streams; whereas the Nile, running in a contrary direction, was slow and sluggish.  The prejudices of a monk, are sufficiently evident in these opinions; but, in justice to Cosmas, it must be remarked, that he labours hard, and not unsuccessfully, to prove that his notions were all the same as those of the most ancient Greek philosophers; and, indeed, his system differs from that of Homer, principally in his assigning a square instead of a round figure to the plane surface, which they both supposed to belong to the earth.  The cosmography of Homer, thus adopted by Cosmas and most Christian writers, modified in some respects by the cosmography they drew from the Scriptures, is a strong proof, as Malte Brun observes, of the powerful influence which the poetical geography of Homer possessed over the opinions even of very distant ages.

Having thus briefly detailed those parts of Cosmas’s work, which are merely curious as letting us into the prevalent cosmography of his time, we shall now proceed to those parts which, as Gibbon remarks, display the knowledge of a merchant.

We have already noticed the inscription at Aduli for which we are indebted to this author, and the light which it throws on the commercial enterprise of the Egyptian sovereigns.  According to Cosmas, the oriental commerce of the Red Sea, in his time, had entirely left the Roman dominions, and settled at Aduli:  this place was regularly visited by merchants from Alexandria and Aela, an Arabian port, at the head of the eastern branch of the Red Sea.  From Aduli, vessels regularly sailed to the East:  here were collected the aromatics, spices, ivory, emeralds, &c. of Ethiopia, and shipped by the merchants of the place in their own vessels to India, Persia, South Arabia, and through Egypt and the north of Arabia, for Rome.

Cosmas was evidently personally acquainted with the west coast of the Indian peninsula.  He enumerates the principal ports, especially those from which pepper was shipped.  This article he describes as a source of great traffic and wealth.  The great island of Sielidiba, or Ceylon, was the mart of the commerce of the Indian ocean.  Its ports were visited by vessels from Persia, India, Ethiopia, South Arabia, and Tzinitza.  If the last country is China, of which there can be little doubt, as he mentions that the Tzinitzae brought to Ceylon silk, aloes, cloves, and sandal-wood, and expressly adds that their country produced silk,—­Cosmas is the first author who fully asserts the intercourse by sea between India