80 Professor Fournet’s [esearches on the 
especially when compared to the intense heat felt in the bay 
of All Saints, situated nearly in the same latitude, but at a 
distance from the high mountains of the Atlantic coasts of 
Brazil. This freshness, considered in a more general man- 
ner, seems, moreover, to be one of the causes of the removal 
of the zone of droughts towards the equator, so that it ac- 
quires an essentially inter-tropical development, contrary to 
what takes place in Africa and in Old California. By gene- 
ralizing still farther this indication, we may even say, that 
in all this aqueous hemisphere, which is colder than the 
other, the whole of the trade-winds, of the isothermal lines, 
and of the pluvial zones, tend to approach the North Pole, in 
such a manner, that the axis of the nearly perpetual rains is 
not exactly at the equator, but encroaches slightly to the 
north. 
If we penetrate from the coast into the interior of the con- 
tinent, we cannot expect to find deserts on a surface so greatly 
varied, nor on the flank of the Andes ; but it may neverthe- 
less be of some interest to investigate the distribution of 
rains over a portion of that region; and in doing this, we 
shall take advantage of the results obtained by Bouguer and 
Sobreviala, combined with those for which we have to thank 
the kindness of MM. D’Orbigny and Auguste de Saint Hi- 
laire. 
The clouds collected together by the north-east winds re- 
main, so to speak, stationary on a portion of the eastern 
flanks of the Andes, at an altitude of nearly 10,000 feet, 
where they cireumscribe the zone of ligneous vegetation ; 
but during the heaviest rains of the rainy season, they be- 
come more elevated, and attain a height of 13,000 feet, and 
give rise to rains, which are distributed in the following 
manner :— 
From Quito (lat. 0° 25’ S.) to Huanuco and Xeuxa (lat. 10’ 
to 12’ §.), the rains which, towards the equator, are pro- 
longed more or less during five or six months, from Novem- 
ber to May, become gradually rarer, so that, at the latter 
points, the air is dry during the months of December, January, 
and February; the climate likewise becomes agreeable, but 
it is accompanied by a want of pastures in the mountains. 
4 
