797 



temperature of Cumana ; but the difference 

 of the coldest month in these two places is 5°. 

 (See above, Vol. iii, p. 386 and 463.) 



ADDITIONAL NOTE ON THE HEIGHT OF THE LAKE OF 

 NICARAGUA ABOVE THE LEVEL OF THE SEA. 



In discussing above, the obstacles which may 

 prevent the possibility, and even the utility of 

 an oceanic canal, (similar to the Caledonian ca- 

 nal, and the canal recently completed in North 

 Holland,) between the eastern and western 

 coasts of America, I spoke of the great height of 

 the basin of Nicaragua. I regretted at the 

 same time, that since my return to Europe, no 

 precise measurement has been made in the isth- 

 mus of Huasacualco, Nicaragua, Panama, and 

 the Atrato. (Vol. vi, p. 241, 253, 269, 281.) 

 It is only at the moment when these sheets are 

 about to appear, that I have had a communica- 

 tion of a very important document, which 

 proves that, " by order of the court of Madrid, 

 addressed to the captain-general of Guatimala, 

 Don Matis de Galvez, the engineer Don Manuel 

 Galisteo executed a survey, in 1781, by means 

 of a water level, from the gulph of Papa- 

 gayo, on the coast of the South-Sea, as far as 

 the Laguna de Nicaragua ; and that, by three 

 hundred and thirty-six stations of ascent, and 

 three hundred and thirty-nine stations of des- 



