The Cambridge History of India, Vol. I: Ancient India v1.c15.151

v1.c15.151

The Indian heights proper are so relatively low, attaining to eight or nine thousand feet only in the far south, that the whole geography of India seems to be dominated by the Himālayas. We recover our sense of the true proportions only when we reflect that even the Himālayas are only five or six miles high, and that India is two thousand miles long. None the less the Himālayas and Tibet are in a very real sense the controlling fact of Indian geography. They pierce upward through more than half the atmosphere into highland climates, and therefore constitute for man a mighty natural boundary. They also guide and limit the winds of the lower air, and thus govern the Indian climate. India is an agricultural land, whose tillage is everywhere dependent, either directly or indirectly, upon the moisture brought from the southern ocean by the great wind swirl of the summer and autumn monsoon. That swirl strikes the Malabar coast as a south-west wind, sweeps over Bengal as a south wind, and drives up the Ganges plains as a south-east wind. The whole movement is induced by suction to where the air is rising over the hot plains of the Middle Indus. There in the summer is one of the hottest places, if not the hottest place in the world. The winds which come down to it off the Irānian plateau, thus completing the swirl stream off a dry land, and bring no moisture. In the winter a dry, bright wind, the north-east monsoon, descends from Tibet over all India. Only in the Punjab and in the far south are there considerable winter rains. The Punjab is in Mediterranean latitudes, where it rains in the winter.