[Sidenote: 53. The Rungeet Gorge.] [Sidenote: 54. The same.] [Sidenote: 55. The Rungeet Bridge, Sikkim.] [Sidenote: 56. A Himalayan Glacier.] [Sidenote: 57. Glacier-fed Torrent in the Himalaya.] [Sidenote: 58. Cane Bridge in the Himalaya.] Finally we have two views in the gorge of the Rungeet river, between Darjeeling and Sikkim, with precipitous sides, and then a glimpse of the Rungeet bridge. The Rungeet drains from the hills of Darjeeling, and from the snow mountains beyond, into a tributary of the Ganges. Several hundred such torrents burst in long succession through deep portals in the Himalayan foot hills and feed the great rivers of the plain, the Brahmaputra and the Ganges. They are perennial rivers, for they originate in the melting of the glaciers, and the Himalayan glaciers cover a vast area, being fed by the monsoon snows. Nearly all the agricultural wealth of Northern India owes its origin to the summer monsoon. [Sidenote: 59. Map of the Himalayan River System.] To understand the fundamental conditions governing the Indian climate let us examine the two concluding maps of this lecture. On the first of them all the country with an elevation of more than fifteen hundred feet is coloured with a dark brown, and that with a lower elevation is coloured a light brown. A great angle of the Indian lowland is seen to project northward into the Asiatic upland. For fifteen hundred miles the Himalaya limits the lowland with a gracefully curving mountain edge, and from this edge there flow the series of tributaries which gather to the rivers Indus, Ganges, and Brahmaputra. Beyond, to the south, are seen in dark brown the higher portions of the Deccan plateau.