The first of the three regions is the Himalaya (q.v.) mountains and their offshoots to the southward, comprising a system of stupendous ranges, the loftiest in the world. They are the _Emodus_ of Ptolemy (among other names), and extend in the shape of a scimitar, with its edge facing southwards, for a distance of 1500 m. along the northern frontier of India. At the north-eastern angle of that frontier, the Dihang river, the connecting link between the Tsanpo of Tibet and the Brahmaputra of Assam, bursts through the main axis of the range. At the opposite or north-western angle, the Indus in like manner pierces the Himalayas, and turns southwards on its course through the Punjab. This wild region is in many parts impenetrable to man, and nowhere yields a passage for a modern army. Ancient and well-known trade routes exist, by means of which merchandise from the Punjab finds its way over heights of 18,000 ft. into Eastern Turkestan and Tibet. The Muztagh (Snowy Mountain), the Karakoram (Black Mountain), and the Changchenmo are the most famous of these passes. The Himalayas not only form a double wall along the north of India, but at both their eastern and western extremities send out ranges to the south, which protect its north-eastern and north-western frontiers. On the north-east, those offshoots, under the name of the Naga and Patkoi mountains, &c., form a barrier between the civilized districts of Assam and the wild tribes of Upper Burma. On the opposite or north-western frontier of India, the mountainous offshoots run down the entire length of the British boundaries from the Himalayas to the sea. As they proceed southwards, their best marked ranges are in turn known as the Safed Koh, the Suliman and the Hala mountains. These massive barriers have peaks of great height, culminating in the Takht-i-Suliman or Throne of Solomon, 11,317 ft. above the level of the sea. But the mountain wall is pierced at the corner where it strikes southwards from the Himalayas by an opening through which the Kabul river flows into India. An adjacent opening, the Khyber Pass, the Kurram Pass to the south of it, the Gomal Pass near Dera Ismail Khan, the Tochi Pass between the two last-named, and the famous Bolan Pass still farther south, furnish the gateways between India and Afghanistan. The Hala, Brahui and Pab mountains, forming the southern hilly offshoots between India and Baluchistan, have a much less elevation. River plains.