Other rivers flow directly into the Atlantic, several of some importance. North of the Amazon a few small rivers are called auriferous, the Araguary of considerable length. South of the Amazon Delta, some rivers flow north and northeast among the mountain ridges, others directly to the ocean. Of the former the most important are the Parnahyba, 900 miles long, navigable in sections, and farther south the São Francisco, the largest river of the coastal region, navigable 192 miles from the coast to the fine Paulo Affonso Falls, and above these for a much greater distance. The Jequitinhonha, 500 miles long, has 84 miles navigable. The most important river south of the São Francisco is the Parahyba do Sul, 658 miles long, rising in the State of São Paulo and flowing across Rio. It is navigable from its mouth a distance of 57 miles and 90 in its upper course.
The Ribeira de Iguapé. The only coast river of economic importance south of Cape Frio is the Ribeira de Iguapé which rises on the table-land of Paraná and after receiving several affluents breaks through the mountains near the boundary of São Paulo. Besides a navigable channel of 118 miles it communicates with an inland waterway called the Iguapé or Mar Pequeno, extending many miles along the coast. In Rio Grande do Sul, where the coastal plain extends half across the State, several rivers partly navigable flow into the important Lagôa dos Patos, with which is connected by a navigable channel, 61 miles long, the Lagôa Mirím.
Lakes. The Lakes of Brazil are few in comparison with the rivers. Those in the Amazon Basin are reservoirs from the overflow of the rivers and rise and fall with these. The coastal section has lagoons and inland channels formed by uplifted beaches; they are usually shallow and some, as in Bahia, are associated with swamps; but on the Alagôas coast the lakes are long, narrow, and deep. The largest coastal lakes are the two in Rio Grande do Sul already mentioned, separated by broad sand beaches from the ocean, with which they communicate by a channel 42 miles long at the south end of the Lagôa dos Patos. This lake is 140 miles long and 30 wide; the Mirím is 78 miles long and at the most 25 wide. Both are navigable, though shallow and with many sand bars.
Climate
This great country of Brazil presents considerable diversity of climate, as already observed. The forest covered Amazon Basin is hot, with slight variation throughout the year, and with heavy rainfalls; but while the average temperature is over 80°, ranging from 65° to 95°, some locations are decidedly preferable to others. The regular rainy season is from November to March, a second of less degree from August to October; also the rainy season is said to last nine months. On the upper Amazon there is a short dry season in January and February. There is a flood time November, December, and higher water from March to June. The average rainfall is about 78 inches, the rise of the river 45 feet. There are east winds, warm and moisture laden, the deflected trades, and colder winds from the west and southwest.
The coast region as far south as Santos is generally warm and humid (except for a stretch at the northeast), with a wet and dry season, though it rains also in the latter, except on the arid northeast coast. A variation occurs in Pernambuco where it rains from March to August, the dry and cooler season in Rio. Here on the edge of the tropics the annual temperature is 5° lower than on the Amazon. At Santos rainfall is heavy and the place is hot, but farther south it is cooler with a wider range of temperature and a more even distribution of rain. In Rio Grande do Sul the mercury ranges from 20° to 80°. Cold southwest storms from the Argentine pampa, occasionally as far as Rio, create discomfort for two or three days at a time. The highest temperature in Rio is 98.7°.
The Brazilian plateau is very different. As a rule the days are hotter and the nights cooler, the air drier, than on the coast at the same latitude. With mean temperature 68° there is occasional frost. Brazilian Guiana is hot and arid, though with more rain at the east and west than in the centre. South of the Amazon from Piauhy to southern Bahia is another semi-arid section with a rainless season from June to December, when streams are dry and fields are burned bare. With heavy rains from January to May, the country is covered with verdure; when these fail, sometimes for successive years, the droughts are destructive to agriculture and cattle. The plateaus of Minas, São Paulo, and Rio have a climate which is modified by luxuriant vegetation, south winds, and their altitude; though Minas Geraes, having forests only along the rivers and at the south, is hotter by day, but with always cool nights. The open lands of São Paulo also have higher daily temperature; the annual mean is 68°-77°. In south Minas and São Paulo frosts occasionally occur. In the State of Rio there is a delightful climate in the high valleys of the Serra do Mar, temperature 45°-90°. The table-lands farther south, Paraná, Santa Catharina, and Rio Grande do Sul enjoy a temperate climate with abundant rain, occasional frost, but no snow. The northern valleys of the Paraná River are sub-tropical, the mean annual temperature of Goyaz City being 77°.
The country over a large extent may be considered healthful; the yellow fever which once afflicted Rio and some other cities has been exterminated by rigid sanitary measures, and the conditions of life on the eastern plateau and in the temperate south are agreeable. The Amazon Valley is of course malarial, though some sections are far better than others. It would seem that the lower parts which are subject to inundation can hardly be made suitable for residence whatever precautions are taken; but the higher lands may be to some extent free of malarial poison, and certain parts have a climate which some Europeans, even Englishmen enjoy.