If you lay your left hand on a map of Tibet so that the part nearest the wrist touches the Pamir, the flat of the hand covers the region of central Tibet, where there is no drainage to the ocean, but where the country falls instead into a number of isolated lake basins. Your thumb will represent the Himalayas, the forefinger the Trans-Himalaya, the middle finger the Karakorum, the third finger the Arka-tagh, and the little finger the Kuen-lun. The highest mountain ranges of the world are under your fingers; and also, as the longest finger is the middle of the five, so the Karakorum is the central range of Tibetan mountains. Now let a little stream of water fall on the back of your hand as you hold it on a table with the fingers spread out. You will see that a tiny quantity remains on the back of the hand, but that the greater part runs away between the fingers. Thus it is in Tibet. The water poured on your hand represents the rain of the south-west monsoon, which falls more abundantly on the eastern part of the country than on the western. The water which stays on the back of the hand represents the small scattered salt lakes on the plateau country which has no drainage to the sea, while the large quantity which runs off between your fingers represents the large rivers which flow between the ranges. [Illustration: TIBET.] Of these rivers two stream eastwards: the Yellow River (the Hwang-ho), which falls into the Yellow Sea, and the Blue River (the Yang-tse-kiang), which empties its waters into the Eastern Sea. The others run southwards, the Mekong into the China Sea, the Salwin, Irawaddy, and Brahmaputra into the great inlet of the Indian Ocean which is called the Bay of Bengal. A large quantity of water runs off along the outer side of your thumb; this is the Ganges, which comes down from the upper valleys of the Himalayas. And, far to the west, nearest to the wrist, you find two rivers with which you are already acquainted: the Indus, which flows southwards into the Arabian Sea, and the Tarim, which runs north and east and falls into Lop-nor. The Himalayas are the loftiest range on earth, and among their crests rise the highest peaks in the world. Three of them should be remembered, for they are so well known: Mount Everest, which, with its 29,000 feet, is the very highest summit in the world; Kinchinjunga (28,200 feet), and Dhwalagiri (26,800 feet). Mount Godwin-Austen in the Karakorum is only about 650 feet lower than Mount Everest.