26 



The National Geographic Magazine 



line than a natural one. The idea of a 

 bank is of water limited by dry land with 

 some elements of permanency about it. 

 Even during the brief period when the 

 line is uncovered, the idea of it is sugges- 

 tive far more of mud and aquatic growths 

 than of dry land and forest growths. 



" To my mind, the natural, simple and 

 obvious idea of the bank of a lake, in this 

 climate, is presented only by the line of 

 mean high water. Here we would first 

 find permanent dry ground every day of 

 an average year. Here an observer, dur- 

 ing every annual round of ordinary sea- 

 sons, would see the water advance to his 

 very feet and then recede, as if some 

 power had drawn the line and said to the 

 waters, ' hitherto shalt thou come but no 

 further.' Here the struggle between for- 

 est growths and aquatic vegetation be- 

 gins to change the landscape. Here lines 

 of drift, the flotsam and jetsam of the 

 waves naturally suggest the limits of the 

 ' bed of the lake.' 



" Without doubt, then, I conclude that 

 mean-high-water mark determines the 

 shore of the lake ; and it now remains to 

 designate that level, and how it shall be 

 found. 



" Several surveys of the proposed Nica- 

 raguan Canal route, beside that of Com- 

 mander Lull above quoted, have been 

 made within the last fifty years. Each 

 found a certain mean high level of the 

 lake, and it might seem a simple solution 

 to take an average of them all. But, as 

 each adopted its own bench-mark on the 

 ocean, and ran its own line of levels to 

 the lake, I have no means of bringing their 

 figures to a common standard. It seems 

 best, therefore, to adopt the figures of that 

 one which is at once the latest and most 

 thorough, which has enjoyed the benefit 

 of all of the investigations of all of its 

 predecessors, and whose bench-marks on 

 the lake are known and can be referred to. 

 That is the survey, still in progress, under 

 the direction of the United States Canal 

 Commission. Its results have not yet 

 been made public, but, by the courtesy of 



Rear- Admiral J. G. Walker, President of 

 the Commission, I am informed of them 

 in a letter dated July lo, 1899, from which 

 I quote: 



" ' In reply I am cabling you to-day, as 

 follows : ' Alexander, Greytown, Six ; ' 

 the six meaning, as per your letter, 106.0 

 as mean high level of lake. This eleva- 

 tion of 106.0 is, to the best of our knowl- 

 edge (Mr. Davis, our hydrographer), the 

 mean high water for a number of 

 years. . . •. 



" ' The highest level of the lake in 1898 

 was 106.7, l^st of November. The eleva- 

 tion of our bench mark on inshore end of 

 boiler at San Carlos is 109.37. • • •' 



" ' A complete copy of this letter will be 

 handed you, and also blue-prints of the 

 maps made by the Commission of the 

 lower end of the lake, which may facili- 

 tate your work.' 



" As this Commission is the highest ex- 

 isting authority, I adopt its finding, and 

 announce my award as follows : 



" The shore line of Lake Nicaragua, 

 at the level of 106.0 feet, by the bench 

 marks of the United States Nicaragua 

 Canal Commission, shall be taken as the 

 bank of said lake referred to in the treaty 

 of 1858." 



The location of the line around the 

 southern margin of the lake was the most 

 difficult part of the whole survey. The 

 country here is a vast morass, densely 

 covered with tropical vegetation, even the 

 sluggish streams being mostly choked 

 with aquatic plants. The high water line 

 was defined as 106 feet, while the level 

 of the lake at the time of the survey was 

 about 102. It became necessary, there- 

 fore, to determine an elevation four feet 

 higher, which was usually several miles- 

 from the water's edge. 



By means of levelling, it was ascer- 

 tained that the swamps had a mean slope 

 toward the lakes of about one foot per 

 mile, and this was made the basis of most 

 of the agreements. A few points on 

 streams were located, the area of Nica- 

 ragua's two-mile zone was calculated, and 



