APPENDIX. 469 



did not take any astronomical observations for the position of Shigatze or Teshu Lombu, 

 and of the consequent error which he has probably committed in altering the latitude of 

 Lassa one degree*. The whole of the lower part of the Sanpo, from Lassa eastward, suffers 

 a similar alteration in his map, which has given room (in space) for the formation of a con- 

 siderable river, called by M. Klaproth, Mon Chu, evidently the Om Chu of Rennell, 

 and our Subanshiri, though M. Klaproth iioav considers it to be our Dihong. This 

 river has not, however, so much as six square degrees allotted to it; but if the course of 

 the Sanpo be restored to its former parallel of latitude, and the Subanshiri introduced — 

 no insignificant river, since it discharges, in the dry season, sixteen thousand feet per 

 second — tbe space for the growth of the Dihong will be, in M. Klaproth's map, most 

 sadly curtailed — reduced, indeed, to nothing. 



I think that I have hinted at the probable cause of all the discussion which we have 

 had on this subject in the early part of this Memoir. The Brahmaputra was described to 

 us as a diminished stream, " little more than a hill torrent," and it " seemed very improba- 

 ble, that such a small body of water could run the distance it is represented or supposed 

 to do." The Dihong, in which alone we could look for a continuation of the Sanpo,f was 

 totally lost sight of, J and long remained forgotten. Time was given to originate Theories, § 

 and to search for Geographical anecdotes amongst antiquated Chinese documents, and 

 the delay which occurred in furnishing information from hence, (from the spot) allowed 

 conjecture to grow into certainty. 



* The Lamas who were sent to survey Thibet, were mathematicians, instructed for the purpose: It is hardly 

 possible that they can have erred one degree of latitude in their survey of the short distance between Lassa and 

 Teshu Lombu, (about one hundred and fifty miles) aud their position of the latter agrees closely with that given 

 by Turner, from observation. I would not contend for their extreme accuracy, or even for an approximation to 

 accuracy, excepting in the position of places actually in their route. They seem to have possessed very little 

 judgment. 



t This would have appeared from the first, had Lieutenant Buri.ton's account of the discharge of the rivers 

 been published. 



t It was never adverted to as a river of great importance, till a letter of mine to the Editor, appeared iu the 

 Government Gazette, about January 1826. 



§ Captain McLachlan's " Theory" appeared in the Edinburgh Philosophical Journal. 



z 3 



