Situation of Zones without Rain, and of Deserts. 83 
Rio Janeiro for several days in succession, and are followed 
by perfect calms; the land breezes only blow in steady, fine 
weather, and the smallest atmospheric disturbances are suffi- 
cient to put an end to them; lastly, a vast number of local 
winds occur during the day, often in very violent gusts, at the 
mouth of all the creeks, and near all the projecting capes of 
the bay. Now, it is to be observed, that the sierra of Espin- 
haco commands all that part of the coast; its vicinity, there- 
fore, individualises in some measure its meteorology, and it 
is thus that this local exception, by which the first navigators 
were so much struck, is explained, if not altogether removed. 
But between Cape Blanco and Cape de Norte, at the extre- 
mity of the Cordillera of the Guyanas, is situated the open- 
ing of the basin of the Amazon, opposite to which the general 
laws follow their course ; that is to say, the rains prevail in 
winter from October till April, conformably to what takes 
place in the whole of the intertropical region of the southern 
hemisphere, and these are followed by the equatorial rains of 
Guyana, at seasons more distinctly marked than they are at 
Choco and on the banks of the Rio Negro ; four annual epochs 
being distinguished, two of droughts, and two of rains. 
The numerous details into which we have entered, indicat- 
ing for this eastern portion of the South American continent 
encroachments analogous to those which have been pointed 
out in the North American continent, render the existence 
of deserts, properly so called, altogether impossible. If de- 
serts were formed according to the same laws which regulate 
those of Africa, or of the western coasts of the New World, 
we ought to find traces of them in the latitudes of Paraguay ; 
but rains are abundant there. It is necessary to ascend the 
ridge of the Andes between 15° and 5° S. lat., in the parallels 
of Pisco and of Payta, to find the less considerable rains of 
Huanuco, and of Xeuxa; then we have, at the line of sepa- 
ration of the waters of the Amazon and of the Paraguay, the 
famous Campos Pariecys, a vast sandy plateau, almost devoid 
of vegetation, and which may be compared to the Chamo or 
Gobi of Mongolia ; lastly, still further to the east, the basins 
of San Francisco, the provinces of Goyaz, of Pernambuco, 
and of Bahiaqui, exhibit here and there in their Sertwos, hills 
