AN ASSUMED INCONSTANCY IN THE LEVEL OF LAKE 



NICARAGUA; A QUESTION OF PERMANENCY 



OF THE NICARAGUA CANAL 



By C. WiLLAHD Hayes, 

 U. S. Geological Survey 



A i)a])er under the aljove heading ])\' Prof. Angelo Heilprin ai)i)ears 

 in the Scientific American of February 24, 1900. To one not familiar 

 witli the investigations which have l)een carried on in this portion of 

 the isthmian region, the conclusions reached l)_y Professor Heili)rin 

 ap|)ear to have some foundation ; and since they cast a doubt upon 

 the feasibilit}' of the proposed Nicaragua Canal and on its })erma- 

 nence after construction, the questions raised are of sufficient impor- 

 tance to be answered somewhat fully. 



Stated very briefly, Professor Heili>rin's ])remises and conclusion 

 are as follows : In 1781 the S{)anish engineer Galisteo determined 

 the altitude of Lake Nicaragua to be 133.11 feet above low water in 

 the Pacific. Later, in 1838, Lieutenant Bail}' ran a line of levels from 

 the Pacific and made the altitude of the lake surface 128.3 feet above 

 low water at San Juan del Sur on the Pacific. In 1852 Colonel Childs 

 surveyed a route for an isthmian canal and determined the elevation 

 of the lake to be about 108 feet above mean sea-level. Subsequent 

 determinations by Lull in 1873, Menocal in 1885, the Maritime Canal 

 Company in 1890. and the Nicaragua Canal Commission in 1898 have 

 reached substantial agreement as to.the elevation of the lake, making 

 its mean about 104 feet above mean tide in the Pacific. This dis- 

 crepancy of 20 to 25 feet between the earlier and later determina- 

 tions of the lake level has generally been ascribed to the inaccuracy 

 of the earlier surveys. Professor Heilprin, however, concludes that 

 the earlier determinations were correct, and that the level of the lake 

 has subsided that amount between the dates of the earlier and the later 

 8urve3's. It will readily be seen that a region subject to a change in 

 elevation of 20 feet in a period of 14 years (between 1838 and 1852) 

 would offer serious obstacles to the construction of a canal of the mag- 

 nitude of the one jtroposed or to its permanency after construction. 



Three causes, singl}' or in combination, might bring al)out a change 

 in altitude of the lake surface: (1) .\ depression of the whole of tliis 



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