790 



lowest, 71. Doctoi Heberden has seen differences 

 as far as fifteen feet in height. I remarked no 

 difference on the 28th September, and the 2d 

 of October, between the two stations of the om- 

 brometer. The rains of these countries are 

 electric, and are preceded by very sensible signs 

 of electricity on the electrometer of Volta, 

 armed with a burning wick. What struck me 

 above all at Cumana, was, that a few minutes 

 before the rain fell, the hair hygrometer conti- 

 nued not only to indicate 67° to 68°, which is a 

 considerable drought for that country, but that 

 (without any change of temperature) it retro- 

 grades one to two degrees towards drought, in 

 proportion as the sky becomes obscure, and 

 takes that intensity of dark blue which pre- 

 cedes the electric explosions. At Cumana, the 

 words thunder, winter, and rain ( trueno, invierno, 

 aguaseroj are synonimous. The thermometer, 

 while it rains, goes down from 24° R., at the 

 utmost to 19°. fc The sky, in darkening, re- 

 mains uniformly blue, displays no vapors di- 

 vided into groupes, and acquires an intensity 

 of colour that goes to 47° of the cyanometer. 

 The cocoa-trees, and all the plants with glossy 

 leaves, are detached in light on the azure vault, 

 and appear suddenly to draw nearer to the ob- 

 server : a perfect calm reigns in the air. The 

 atmospheric electricity, which I found gene- 

 nerally null at Cumana, from 7 h in the morning 



