74 



A VOYAGE TO 



Boojc VII, 



perfes them, it proceeds from the increafe of the 

 force of the winds during the winter, in a region 

 Bearer the earth than in fummer and the nearer the 

 lower part of this region is to the fiirface of the 

 earth, the nearer alfo will be the upper part^ while, 

 0n the contrary, in the fummer, the higher the lower 

 part of this current of air is, the higher will be alfp 

 its upper part ; and, as we muft fuppofe, with all 

 philolophers, that the vapours of the earth can afcend 

 jonly to that height, where the gravity of the parti- 

 cles of the vapours are equal to thofe of the air ; and 

 the rapidity of the wind extending in fummer to 

 |:hefe limits, they are conTequently involved in its 

 iriolent impulfe and thence there cannot be fuch a 

 multitude of conglomerations as to form the mift 

 fo common in winter for the winds in this feafon 

 ftrongly blov/ing through a region nearer the earth, 

 the agitatioi) in the upper parts is proportionally lefs. 

 And diis current of air being below the region to 

 which vapours can afcend, the fpace intercepted be- 

 tween the upper part of this current, and the part 

 to which vapours rife, becomes filled with them. 

 All this feems natural, and is confirmed l>y expe- 

 rience 'y for in winter the fouth winds are ftronger on 

 the land than in fummer. But as a further proof 

 may be thought necelTary, I haye ^dded th,e fol- 

 lowing. 



It has been faid that in the town of Chocope, 

 two very hard and cqntinual rains have happenned ; 

 ^nd'that the fame thing is more frequently feen at 

 f umbez, and other towns of thofe parts, after fome 

 years of continual drought, which feems ftrange ^ 

 far that being in the country of Valles, and not 

 at all different from Lima, no rain would naturally 

 be expeded there. Two catifes for this, however, 

 have occurred to me, one of them flowing from the 

 other. I lhall begin with the firfl as prodndive of 

 t|ie fecond. ' . 



