Railways in India serve different purposes--the ordinary purpose of trade and passenger communication, and also the special purposes pf the safeguarding the internal and external peace of the country, and of protecting special districts against famine by facilitating the movement of grain. For this reason the interest on capital expended on all the lines cannot be judged by a purely commercial standard. They are administered in three separate ways--as guaranteed, state or assisted lines. In the early days of railway enterprise the agency of private companies guaranteed by the state was exclusively employed, and nearly all the great trunk lines were made under this system, but the leases of the last three of these lines, the Great Indian Peninsula, the Bombay Baroda and Central India, and the Madras companies, fell in respectively in 1900, 1905 and 1907. In 1870 a new policy of railway development by the direct agency of the state was inaugurated; and in 1880 the system of encouraging private enterprise by state assistance was again resorted to. Both agencies are now employed side by side. The administration of railways was formerly under a secretary in the public works department; but since 1905 it has been placed in charge of a railway board, consisting of a president and two members, which is connected with, though not subordinate to, the department of commerce and industry. In 1908 the total length of railways open in India was 30,578, m., which carried 330 million passengers and 64 million tons of goods, and yielded a net profit exceeding 4%. Irrigation. Facilities for irrigation (q.v.) vary widely, and irrigation works differ both in extent and in character. The main distinction arises from the fact that the rivers of northern India are fed by the Himalayan snows, and, therefore, afford a supply of water which surpasses in constancy and volume any of the rivers of the south. In Bombay and Madras almost all the irrigation systems, except in the deltas of the chief rivers, are dependent on reservoirs or "tanks," which collect the rainfall of the adjacent hills. In Sind and the Punjab there are many canals which act merely as distributaries of the overflow of the great rivers at the time of inundation; but where the utility of the canals has been increased by permanent head-works the supply of water is perennial and practically inexhaustible, thus contrasting favourably with the less certain protection given by tanks. The Irrigation Commission of 1901 advised an expenditure of 30 millions sterling, spread over a term of twenty years, and irrigating 6½ million acres in addition to the 47 millions already irrigated at that time; but it was estimated that that programme would practically exhaust the irrigable land in India, and that some of the later works would be merely protective against the danger of famine, and would not be financially productive. Buildings and roads.