CLIMATIC CONDITIONS. —With the exception of the last-mentioned region the climate of Siam is monsoonal in character, and there are three seasons, a cool, a hot, and a rainy. The mean temperature is high throughout the year, and in the lowlands does not fall below 70°F. even during the cool season. The rainfall is least along the south coast and in the valley of the Lower Menam, where it does not exceed 60 inches. On the more elevated lands to the north and east it ranges from 60 to 80 inches, while in the Malay Peninsula, where precipitation occurs practically at all seasons, it exceeds the latter amount.
UPPER SIAM.—The mountain ranges of this region are covered with forests, while in the intervening valleys there are considerable areas of fertile soil. Teak, which is the principal product of the forests, is floated down to the coast either at Bangkok by way of the Menam, or at Moulmein by way of the Salwen. Within recent years some attempts have been made to protect these forests from the reckless destruction to which they have for long been subject. Other valuable timber trees are known to exist in Upper Siam, but they are too heavy to be floated down the rivers, and their exploitation must await the development of the railway system. In the valleys rice is the principal crop, but, as it is unsuitable for export, the bulk of it is consumed at home. Tobacco is
also grown, mainly for domestic use, and among other crops are cotton, tea, and betel-nut. The chief commercial town of the region is Chieng-mai, which is situated on the Meping and is engaged in trade with the Shan states.
LOWER SIAM.—The alluvial soil, monsoonal rainfall, and high temperature of the lowlands of Siam are peculiarly favourable to the cultivation of rice, which is the chief product of the region, and not only provides the staple food for man and beast within it, but forms the basis of the greater part of its foreign trade. Market gardening gives employment to large numbers of Chinese, especially in the vicinity of the towns. Various attempts have been made to grow cotton, but so far without much success. Other crops include maize, sugar-cane, sesamum, and coconuts.
The lowlands contain the greater part of the population of Siam and its chief towns. Bangkok, the capital, which is situated on the Menam about twenty-five miles from its mouth, is the great port of the country, though it has a very indifferent harbour. It is engaged in the preparation of rice and teak for export, in shipbuilding, and in engineering.