On the Cattfe of Earthqttahs. 341 



•45. All thefe warm bodies dilate the ambient air of the 

 atmofplicre bv which they are covered. 



■ 27. The vapours of the fea, beiiig attrafled around all the 

 coaits towards the centre of the ifland, according to the 20th, 

 21 ft, 22d, 23d, and 24th obfervations, produce an afccnt of 

 the clouds much 'more confiderable on land than at fea. This 

 elevation of the vapours appears in a very remarkable manner 

 in ail the iflands of the torrid zone, when one is^at the di- 

 ftance of fix or eight leagues from them, and even more. 

 Experienced mariners employ this indication fometimes to 

 determine the proximity of land. 



28. All the different breezes here mentioned change their 

 direftion in the night-time: they decreafe in velocity from 

 fun-fet to 9, 10, or IT at night. After which a calm takes 

 p'ace for fome moments ; the land wind then prevails during 

 the whole nicht, in confajuence of the condenfation of the 

 \'apours of the atmofphere, which being cooled, and acquir- 

 ing gravity by the abfence of the fim, in their defcent expel 

 the ambient air, which they prefs on all fides from the centre 

 towards the circumference, that is to fay, from the interior 

 of the ifland towards the fea: this is what is called the land 

 breeze. 



29. Of all the breezes here mentioned, the eaft and north 

 winds are more frequent in the countries of the torrid zone 

 than thofe of the weft and fouth, except in the diftrids men- 

 tioned in the 23d and 24th obfervations. 



30. The mountains form fo many dikes that oppofe the 

 courfe of the clouds which are there accumulated, and, be- 

 ing condenfcd, fall down in rain on the fides and at the bot- 

 tom of the mountains. 



3T. 'I'hc plains on the fide where the clouds are accumu- 

 lated are fertile, and thofe on the oppofite fide are dry. Thcfe 

 mountains therefore divide thefe countries intx) two different 

 climates. 



32. Earthquakes qre much niorefrcqnent in arid countries 

 than in diftrii^ts watered by rain ; becaufe, in all probability, 

 the vapours of the interior part of the country arc there col- 

 Jerted, and proceed thither more than to thofe where the rains 

 render the eartfi compact. 



33. The faces of mounlains wliich look towards the north 

 and the ealt, are more cooled by the rains than thofe which 

 look towards the foulh and weft. 



34. In the Spanidi plains, fitualcd in the centre of Saint 

 Domintro, there are feveral infulated mountains, which, nol- 

 withl^anding their finall extent, exhibit the diiferent tempe- 

 ratures indicated around their fules by fliades of verdure ana- 



^' ' Ioi!()US 



