32 



The National Geographic Magazine 



sand and thus render the San Juan use- 

 less for the purposes of a canal beyond 

 their junction. The canal route, there- 

 fore, is compelled here to leave the San 

 Juan, which can no longer be of service, 

 and find to the sea an independent way. 



Lake Nicaragua can furnish an. unlim- 

 ited supply of water to the canal. It is be- 

 lieved that it varies in its level as much 

 as thirteen feet. Such an extreme fluc- 

 tuation occurs, however, only at relatively 

 remote intervals. This fluctuation will be 

 reduced by the construction of the dam in 

 the San Juan River just above the San 

 Carlos, whose waters cannot be used be- 

 cause of the load of sediment they carry. 



To reach the summit level from the At- 

 lantic side five locks will be constructed, 

 the first having a lift of thirty-six and one- 

 half feet and the other four a uniform lift 

 of eighteen and one-half feet, except the 

 lock at the summit, the lift of which will 

 vary with the level of the lake. The locks 

 will be seven hundred and forty feet long 

 by eighty feet wide in the clear, with a 

 depth of thirty-five feet over the miter-sill. 



From the Pacific side the summit will be 

 reached by four locks of uniform lift of 

 twenty-eight and one-half feet. It is as- 

 sumed that the mean level of the two 

 oceans is about the same. The mean 

 range of tides on the east is about one foot 

 and that on the west side about eight feet. 

 The following table gives the distances 

 on the Nicaragua route : 



Number of miles of canal proper 67.33 



Number of miles of river improved... 27.96 

 Number of miles not requiring im- 

 provement 17.26 



Number of miles of lake channel 300 



feet wide 22 . 19 



Number of miles of lake not requiring 



improvement 48 . 74 



Number of miles of harbors and en- 

 trances to same 3 . 05 



Total number of miles from ocean to 

 ocean, measured from the 6-fathom 

 curves 186 . 53 



Time necessary to pass through the 

 canal, 33 hours. 



The Isthmian Commission believe that 

 it would take ten years to construct the 

 canal, and that the cost would be at least 

 $200,000,000. 



THE TSANGPO 



By James Mascarene Hubbard 



THE Tsangpo is in several re- 

 spects the most remarkable river 

 in the world. It is the highest 

 of all navigable streams, flowing for 

 nearly a thousand miles at an elevation 

 of from 11,000 feet to 14,000 feet. Dur- 

 ing the greater part of its course its 

 current is sluggish, but for a hundred 

 miles or more the mighty river, in its 

 descent to the coast plain, runs with the 

 speed of a mountain-torrent. Though 

 one of the largest of Central Asian 

 streams, it has never been followed from 

 its source to its mouth, and until recent- 

 ly it was doubtful of which of two well- 

 known rivers it was the head-waters. 



The attempts to solve its mysteries have 

 been attended with an almost unparal- 

 leled heroism, endurance, steadfastness, 

 and self-sacrifice. For the principal ex- 

 plorers of the Tsangpo have been ani- 

 mated, not as those who sought the 

 fountain-springs of the Nile, by the hope 

 of the world's applause at their success 

 — that was denied them — but for a sim- 

 ple daily wage and the consciousness of 

 loyalty to duty. 



The physical history of the Tsangpo 

 is briefly this : It rises in the extreme 

 southwestern corner of Tibet, close to. 

 the sources of the Ganges, the Indus, 

 and its great affluent, the Sutlej, at a 



