The season of the year was then unfit for voyaging; for the periodical winds prevailed, which at that season do not blow there from the north, as with us, but from the Great Sea, in the direction of the south wind.[781] Moreover it was reported that there the sea was fit for navigation after the beginning of winter, from the setting of the Pleiades[782] until the winter solstice; for at that season mild breezes usually blow from the land, drenched as it has been with great rains; and these winds are convenient on a coasting voyage both for oars and sails. Nearchus, who had been placed in command of the fleet, waited for the coasting season; but Alexander, starting from Patala, advanced with all his army as far as the river Arabius.[783] He then took half of the shield-bearing guards and archers, the infantry regiments called foot Companions, the guard of the Companion cavalry, a squadron of each of the other cavalry regiments, and all the horse-bowmen, and turned away thence on the left towards the sea to dig wells, so that there might be abundance of them for the fleet sailing along on the coasting voyage; and at the same time to make an unexpected attack upon the Oritians,[784] a tribe of the Indians in this region, which had long been independent. This he meditated doing because they had performed no friendly act either to himself or his army. He placed Hephaestion in command of the forces left behind. The Arabitians,[785] another independent tribe dwelling near the river Arabius, thinking that they could not cope with Alexander in battle, and yet being unwilling to submit to him, fled into the desert when they heard that he was approaching. But crossing the river Arabius, which was both narrow and shallow, and travelling by night through the greater part of the desert, he came near the inhabited country at daybreak. Then ordering the infantry to follow him in regular line, he took the cavalry with him, dividing it into squadrons, that it might occupy a very large part of the plain, and thus marched into the land of the Oritians. All those who turned to defend themselves were cut to pieces by the cavalry, and many of the others were taken prisoners. He then encamped near a small piece of water; but when Hephaestion formed a junction with him, he advanced farther. Arriving at the largest village of the tribe of the Oritians, which was called Rhambacia,[786] he commended the place and thought that if he colonized a city there it would become great and prosperous. He therefore left Hephaestion behind to carry out this project.[787] CHAPTER XXII. MARCH THROUGH THE DESERT OF GADROSIA.