These things, he says, were observed by himself and by others on their journey into India from the Paropamisadæ. This was after the setting of the Pleiades,[340] and during their stay in the mountainous country in the territory of the Hypasii, and in that of Assacanus during the winter. At the beginning of spring they descended into the plains to a large city called Taxila,[341] thence they proceeded to the Hydaspes and the country of Porus. During the winter they saw no rain, but only snow. The first rain which fell was at Taxila. After their descent to the Hydaspes and the conquest of Porus, their progress was eastwards to the Hypanis, and thence again to the Hydaspes. At this time it rained continually, and particularly during the blowing of the Etesian winds, but at the rising of Arcturus the rains ceased. They remained at the Hydaspes while the ships were constructing, and began their voyage not many days before the setting of the Pleiades, and were occupied during the whole autumn, winter, and the ensuing spring and summer, in sailing down the river, and arrived at Patalene[342] about the rising of the Dog-Star;[343] during the passage down the river, which lasted ten months, they did not experience rain at any place, not even when the Etesian winds were at their height, when the rivers were full and the plains overflowed; the sea could not be navigated on account of the blowing of contrary winds, but no land breezes succeeded. 18. Nearchus gives the same account, but does not agree with Aristobulus respecting the rains in summer, but says that the plains are watered by rain in the summer, and that they are without rain in winter. Both writers, however, speak of the rise of the rivers. Nearchus says, that the men encamped upon the Acesines[344] were obliged to change their situation for another more elevated, and that this was at the time of the rise of the river, and of the summer solstice. Aristobulus gives even the measure of the height to which the river rises, namely, forty cubits, of which twenty would fill the channel beyond its previous depth up to the margin, and the other twenty are the measure of the water when it overflows the plains.