Situation of Zones without Rain, and of Deserts. 81 
To this region rapidly succeed the great elevations and the 
variable climate of Cusco and of Arequipa (lat. 13° to 16° S.), 
where rains and storms are of daily occurrence. Towards 
Chuquisaca and Cochabamba (about latitude 19°), at a height 
of nearly 10,000 feet, Mr Pentland was exposed to constant 
rains during his excursions, from the month of January to 
the 1st of April. Lastly, in the central portion of Chili 
(lat. 33° S.), the air again becomes very dry, and the sky is 
constantly free from clouds during our winter ; that region, 
like Valparaiso and Sant-Yago, being situated in the zone of 
summer rains from May to September, a period of the year 
which in that hemisphere corresponds to winter. 
Descending from these great heights to the lower regions 
of the eastern base of the Andes, we find (between lat. 0° and 
13° S.) rains which last during the whole year, so that this 
band ought to be regarded as forming a lateral appendage to 
the perpetual rains of the virgin forests of Rio Negro and of 
the Amazon; hence it results, that from one side to the 
other, and between the tropic and the equator, we have, ac- 
cording to the parallels and the heights, stations at which it 
never rains (environs of Lima); others where the rains con- 
tinue about three months; and, lastly, where they are of 
daily occurrence. 
In this central portion of the continent, the vast regions of 
La Plata, Buenos Ayres, of Uruguay, and of Paraguay, are 
eyerywhere subject to falls of water, which are variable in 
their duration, in the epoch of their occurrence, and in their 
abundance. Thus, commencing from Patagonia, and on the 
Pampas (lat. 35° S.), they take place regularly, but are not 
abundant, and they only occur during the months of June, 
July, and August, which there constitute the winter. In 
Corrientes, and especially at Assumption, in Paraguay (lat. 
30° to 25° S.), they are more or less abundant at all seasons. 
Lastly, in the warm region, commencing from 20° S. as far as 
the line of Moxos and Chiquitos (Brazil), it rains during the 
six months comprised between October and March. This 
regularity subsists on the plateau of Brazil, in the districts 
of St Paul, of Minas Geraes, and of Goyaz, where the rains 
VOL, XXXVIII. NO. LXXV.—JAN. 1845. F 
