Southward from the bases of the Himalaya and the Sulaiman mountains the great plain of northern India spreads out, reaching across the whole breadth of Hindustan from the Arabian Sea to the Gulf of Bengal.
Southward of the great plain the land begins to rise again. The first elevations reached in this direction are those of the long range of the Aravali hills, which extend for four hundred miles from northeast to southwest, marking the edge of the western section of the great plain. It is bold and precipitous on that side which falls toward the Indian desert, but less so on the southeast; its average height is about three thousand feet, Mount Abu, being the highest point.
Behind the Aravali hills lie the plateaus of Malwa and Bundelkhand, extending over the country generally termed central India; These are fertile tablelands of uneven surface elevated from one thousand five hundred to two thousand feet above the sea level, and traversed by a number of minor hill ridges.
The greater part of south India is occupied by the wide tableland of the Deccan. The name ghat was originally applied by the natives to the passes in the outer slopes of the ranges which run parallel with the two coasts of the southern portion of the great promontory of India enclosing the Deccan, and which had to be ascended to reach the high interior country from the coast; but this name Ghat has been transferred to these ranges or outer edges of the tableland themselves.
The western Ghats, about eight hundred miles in length, clothed with magnificent teak forests, form by far the boldest and most continuous escarpment of the Deccan plateau, ascending abruptly from a low base, generally at a distance of about thirty miles from the sea.
The eastern Ghats differ from the western in being much lower, in rising at a much greater distance from the coast of the Bay of Bengal, and with a gentle slope, giving access by wide openings to the interior. Their average height is about fifteen hundred feet, the highest point, near Madras, only about three thousand feet above the sea. The Deccan plateau between these supporting buttresses has thus a gradual eastward slope, and is characterized by undulating treeless plains, ridges and isolated flat-topped hills capped with basalt. Large portions of it are also covered with jungle, often overgrowing the ruins of former towns and temples, but there is no extent of forest.
Between the eastern Ghats and the sea lies the extensive maritime plain generally named the Karnatic, reaching back from the Coromandel coast for about fifty miles. The soil of this plain proves abundantly fertile when it is watered, but there are few streams, and a supply of water for irrigation has to be stored in reservoirs.
Rivers.—The river system of India consists of three great rivers: the Indus, the Ganges, the Bramaputra.
The Indus rises on the northern slopes of the Himalayas, sweeps round and enters at the western extremity of the range, and waters the Punjab.