INDQ-CHIKA- 



srs 



acivpl.M.1 .--i pr^l-id-ly nni. Ur (nun thfl truth. The constituent ele- 

 ments ore the Siamese proper in the southern provinces, the kindred 

 Shaim ciml Laos in the north -western ami north-eastern districts, 

 some Camliojans, half- assimilated to the Siamese type, toward* ih<: 

 Cambojiin frontier, and the Chinese, who are very numerous, especi- 

 ally in the capital) and about the lower Mertam valley- 



Physical Features. — Except in the central parts, watered 1>y 

 the middle and lowyr Meiiam, Siam i« esKeutfally an upland region, 

 everywhere diversified by Isolated hills, broken ridges, or long moun- 

 lain ranges A pMiuiwml fi-uture of this invgulur and little known 

 orographic system is the transverse Dong Phriya-fei chain, which 

 north of Siam proper rnns east and west, intersecting the course of 

 all the streams flowing southward* to the Men am. Here the Meping, 

 or Upper Menam iUelf, traverser a deep rocky channel, which in a 

 space of about 90 miles between Zimme (Xieny-uuii), and Habeug 

 is interrupted by over thirty rapids, mostly, however, accessible to 

 steamers at high water. The elevated land presents the general 

 aspect of plateaux all disposed north-east and south-west between 

 the river valley*, but nowhere exceeding 3Ti00 feet in height, except 

 close to the Yunnan frontier. From the lofty summit crowned by 

 the city of XJeng-tung the eye sweeps over a boundless prospect of 

 ])i-:ik> rind domes oivcring a great part of the Lao country* From 

 this point branch off two ranges,, one running at a height of about. 

 5000 feet between the Menam valley imd Bunuah southwards to 

 Tenasserim, the other towards the Battumbutig and Parsut highlands 

 Imtween Siam and Camboja, 



In the southern and eastern Lao country, along the course of the Me- 

 khong, the relief of tlio land Iiils been largely caused bv the upheaval or 

 the Devonian system HuW^iientLy to the development of the thick triaaric 

 deposits resting on tin: linicstoiic formations. Further modiuVationB are 

 due to the eruption of the porphyries cropping out here .11 id tlu-iv, t'i ]M>st- 

 trrasKic denudation, to the erosive action of running waturs, and to alluvial 

 deposits. 



The alluvial formation finds its widest development in the groat 

 central plain of ludo- China, which constitutes Siam proper, and 

 which is abundantly watered by the Mcnniu and its numerous 

 affluents from the east and west Rising in the SI inn country, near 

 the converging point of the ifalwin and Mekhong basins, at a beight 

 of soma 900 feet above sea level, the Meping, or western bnuacli, 

 usually but wrongly regarded as the true upper course of the 

 MeUJliu, How* mainly in a smithi-idy dir.vtiun 1u Ifuheh wl.erv h. 

 is joined by the Menatn-vang, a large alHuent from the north-east. 



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