Thus by the exploits and far-sighted policy of Alexander the Great were the then civilized nations of Europe made practically acquainted with calicoes, muslins, and other piece-goods--clothing materials which they had never previously seen, although probably for more than two thousand years these had been woven in the simple looms of India from the soft, white, “vegetable-lamb’s wool that grew on trees”; and had during that long period supplied the principal raiment of a population of many millions. As the Persians had an unconquerable dislike of the sea, the seat of intercourse with India was the more easily established in Egypt, and it is remarkable how soon and how regularly the commerce with the East came to be carried on by the channel in which the sagacity of Alexander had destined it to flow. The Egyptian merchants took on board their cargoes of Indian produce at Patala (now Tatta) on the lower Delta of the Indus, at Barygaza (now Baroche, on the Nerbuddah) and in the Gulf of Cambay, and probably also at Kurrachee and Surat. As their vessels were of small burden, and as they, themselves, though sufficiently acquainted with astronomy to make some use of the stars, had no knowledge of the mariner’s compass, the prudent merchantmen crept timidly along within sight of land, following the outline of every bay, and skirting the shores of Persia and Arabia and the western coast of Lower Egypt to Berenice. Though the course was tedious and the voyage prolonged, the traffic prospered, and was thus carried on for more than three centuries. When Egypt was conquered by Julius Cæsar, B.C. 30, and, after the battle of Actium, became a Roman province under Augustus, it continued undisturbed. The taste for luxury at Rome gave a new impetus to commerce with India, and at this time four hundred sailing craft were engaged in the trade. About A.D. 50, an important discovery was made which greatly facilitated intercourse between Egypt and the East, and diminished the time occupied by the voyage. Hippalus, the commander of a vessel trading with India, noticed the periodical winds called the “monsoons,” or “trade-winds,” and how steadily they blew during one part of the year from the east, and during the other from the west. Having observed this to occur regularly every year, he ventured to relinquish the slow and circuitous coasting route, and stretched boldly from the mouth of the Arabian Gulf across the ocean, and was carried by the western monsoon to Musiris, on the Malabar coast. This was one of the greatest achievements in navigation in ancient history, and opened the best communication between East and West that was known for fourteen hundred years afterwards. Arrian (who wrote A.D. 131) says that at that date Indian cottons of large width, fine cottons, muslins, plain and figured, and cotton for stuffing couches and beds, were landed at Aduli (the present Massowah), and that Barygaza was the port from which they were chiefly shipped.