After travelling 1500 miles on camels and dromedaries, the whistle of an engine sounds like the sweetest music to the ear. At Nushki (see map, p. 132), the furthermost station of the Indian railway, I took leave of my Baluchi servants, stepped into a train, and was carried past the garrison town of Quetta south-eastwards to the Indus. Here we find that one branch of the railway follows the river closely on its western bank to Karachi, one of the principal seaports of British India. Our train, however, carries us northwards along the eastern bank to Rawalpindi, an important military station near the borders of Kashmir. [Illustration: MAP OF NORTHERN INDIA, SHOWING RIVERS AND MOUNTAIN RANGES.] In the large roomy compartment it is as warm as it was lately in Baluchistan, or nearly 107 deg. To shade the railway carriages from the burning sun overhead, they are provided with a kind of wooden cover with flaps falling down half over the windows. The glass is not white, as in European carriage windows, but dark blue or green, otherwise the reflexion of the sunlight from the ground would be too dazzling. On either side two windows have, instead of glass, a lattice of root fibres which are kept wet automatically night and day. Outside the window is a ventilator, which, set in action by the motion of the train, forces a rapid current of air through the wet network of fibres. Thereby the air is cooled some eighteen or twenty degrees, and it is pleasant to sit partly undressed in the draught. Look a moment at the map. South of the Himalayas the Indian peninsula forms an inverted triangle, the apex of which juts out into the Indian Ocean like a tooth, but the northern part, at the base, is broad. Here flow the three large rivers of India, the Indus, the Ganges, and the Bramaputra. The last mentioned waters the plains of Assam at the eastern angle of the triangle. On the banks of the Ganges stands a swarm of famous large towns, some of which we shall visit when we return from Tibet. The Ganges and Bramaputra have a delta in common, through which their waters pass by innumerable arms out into the Bay of Bengal. At the western angle of the triangle the Indus streams down to the Arabian Sea. The sources of the Indus and Bramaputra lie close to each other, up in Tibet, and the Himalayas are set like an immense jewel between the glistening silver threads of the two rivers. On the west the Indus cuts through a valley as much as 10,000 feet deep, and on the east the Bramaputra makes its way down to the lowlands through a deep-cut cleft not less wild and awesome.