463 APPENDIX. 



mountains, is too small to be the channel of such a stream. The first part of this objec- 

 tion has been answered in a foregoing note, but much more might be adduced to prove that 

 a river having its rise in and flowing through that arid and elevated tract, must be very 

 inferior in comparison with one draining a country with a moist climate ; but, indeed, the 

 Sanpo, up to the ninety-seventh degree of longitude, drains a smaller space than the Ganges 

 to Benares, the former being 33-8 degrees* and the latter 37*0 degrees, yet it is consider- 

 ably larger. The second objection has also been met in a note to a former part of this paper. 

 True, the Dihong was but one hundred yardsf wide, yet the steep slope of the mountain's 

 sides induced an impression that the bed must possess immense depth : but pursue the 

 question to calculation, and all appearance of difficulty vanishes. Suppose the discharge 

 still fifty thousand feet per second, and the mean velocity of the current at that spot three 

 miles per hour, the mean depth required to give that discharge is but thirty-seven feet- — 

 the mean depth in the dry season at Goalpara, where the breadth is twelve hundred 

 yards, is twenty-one feet, and the depth of the principal channel there thirty-three 

 feet. And supposing the discharge the same, and the velocity no more than two miles 

 an hour, the mean depth required is but fifty-five feet: also, I conceive, far within the 

 bounds of possibility. 



It must not be forgotten, that to connect the Sanpo with the Irawadi, according to 

 M. Klaproth's view, not less than four hundred and fifty miles (by the most direct 

 possible route) must be added to the course of the Sanpo, over and above what is 

 necessary to connect it with the Dihong. This is not his only difficulty : in addition to 

 those I have already stated ; his second map still requires considerable alterations in 

 longitude to bring in my Surveys, cramping still more the crowded streams, which, with 

 most unnatural parallelism, crawl in nearer contiguity than is known in any other part of 

 the world, through his map, between the sources of the Brahmaputra and China. 



Notice has already been taken, in an excellent article J on the subject, in the Oriental 

 Quarterly Magazine, thatM. Klaproth was entirely mistaken in supposing that Turner 



* Including from the highest ridge of the Himalaya to the thirty-first degree of latitude, sometimes a little 

 more. IM. Klaproth's map would give it less space. 



t The breadth is said to be greater further within the hills. I have seen a cane bridge, of eighty yards length, 

 over the Brahmaputra. The Ahors declare that the Dihong is always too wide to admit of a bridge being thrown over. 



+ Memoir on the Course of the Great River of Thibet. 



