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BULLETIN 186, UNITED STATES NATIONAL MUSEUM 



Nam ranges, and these by the Phetchabun mountains, which, in this 

 region, are the boundary hills between Thailand and the territories 

 of the French. 



Between each couple of these north-south ranges lies the valley of 

 a river that finally, after dropping through a constricted gorge to 

 the great plain of Central Thailand, unites its waters with those of 

 its sister streams and others to form the Mae Nam Chao Phaya, the 

 chief river of the Kingdom. The river flowing between the Thanon 



-Relationship of northern Thailand to neighboring regions: 



1. Northern Thailand. 7. Bas-Laos. 



2. Pegu. 8. Tongking. 



3. Karen-ni. 9. Annam. 



4. Kengtung. 10. Cambodia. 



5. Haut-Laos. 11. Cochin-China. 



6. Moyen-Laos 12. Tenasserim. 



