705 



Cassan loses its importance, when we recollect 

 how little precision this naturalist generally 

 observes in his labors. He does not admit that 

 the movements of the mercury, even in their ir- 

 regularity, correspond perfectly with the move- 

 ments of the Ocean on the western coast of 

 Saint Lucia ; he pretends also ■ 4 that the baro- 

 metric formula used in Europe cannot be ap- 

 plied to the measure of the height of the moun- 

 tains situated in the tropics." The few obser- 

 vations that have hitherto been published on 

 the horary variations in the island of Saint 

 Domingo * might lead us to suspect inequali- 

 ties which would only disappear by employing 

 the mean ; but it is to be feared that travellers, 

 by not observing from hour to hour, have con- 

 founded either the different epochas of the sta- 

 tionary state of the barometer, or the effects of 

 the rainy season, and of that of drought. An 

 observer in India, who merits the highest confi- 

 dence, M. Horsburgh, has made very curious 

 remarks on the climateric and local circum- 

 stances, which sometimes mask, or alter the 

 type of the amospheric tides, even in the torrid 

 zone. He saw that the rains at Bombay inter- 

 rupted the period altogether; but that a tendency 



* Chanvalon gives for the limit-hours -f- 22 ; — 6 j -f- 10 ; 

 Moreau de Saint Mery : +23; — 3 j M. Moreau de Jon- 

 nes, + 21 ; — 2 j -f 7 ; — 13. {Hist Phys. des Ant. Franc, 

 Tom. i, p. 417.) 



VOL. VI. 3 A 



