146 



traveller found by trigonometrical measurement the absolute 

 height to be 2213 toises. La Caille, speaking of this mea- 

 surement in the Memoirs of the Academy *, expressed his 

 doubts of the accuracy of the result. These doubts have 

 been revived by Bouguer • who, in fixing the limits of the 

 perpetual snows under different zones, has examined with 

 his usual sagacity P. FeuilleVs operations ; and he concludes, 

 that the height of the Peak does not exceed 2062 toises f. 



There exists also another measurement of this mountain, 

 made during the voyage of Pj Feuillee, by M. Verguin. 

 This measurement, merely barometrical, has been hitherto 

 neglected ; because, having been calculated according to the 

 method of Cassini, it had given the excessive height of 2624 

 toises J . This error, which exceeds two-fifths of the total 

 height of the volcano, will be reduced to one-twentieth, if 

 the method of Laplace, and the coefficient of Ramond, be ap- 

 plied to the observations of Mr. Verguin ; and if we suppose, 

 what is probable enough in a latitude so southerly, that the 

 pressure of the air did not very sensibly change in the space 

 of three days. On the 31st of July, 1724, P. Feuillee's 

 barometer, at the port of Orotava, stood at 27 inches 9*7 

 lines. On the 3d of August the same instrument was found 



* Mem. de l'Academie, 1746, p. 143. Voy. de la Flore, 

 t. i, p. 114. 



+ Fig. de la Terre, p. 48. Deluc, Rech. sur les Mod. de 

 1' Atmosphere, § 280 and 763. Notwithstanding the examina- 

 tion of Bouguer, and the well known measurement of Borda, 

 we still find, in several physical works, the height of the 

 Peak estimated at 2097, 2180, and 2270 toises. -Seethe 

 third edition of Marsden's valuable History of Sumatra, 

 published in 1811, p. 14 ; and Breislack's Geology, t. i. 

 p. 6, in which the table of heights swarms with typogra- 

 phical errors. 



+ Mem. de l'Academie, 1733, p. 45. 



