SAO FRANCISCO, a river of eastern Brazil rising in the south-west part of the state of Minas Geraes, about 20° 3o' S., 40' W., near the narrow valley of the Rio Grande, a tribu tary of the Parana., and within 24o m. of the coast west of Rio de Janeiro. It flows in a general north-north-east direction across the great central plateau of Brazil to about lat. 9° 3o' S., long. W., where it turns north-east and then south-east in a great bend, entering the Atlantic in lat. ro° 29' S. It has a total length of about 1,800 m. and a fall of 2,700-2,800 ft. It is navigable from the Atlantic to Piranhas (148 m.) and is nearly r m. wide at Penedo, 2 2 m. from the sea. Above Piranhas, about 193 m. from its mouth, are the falls of Paulo Affonso, where the river plunges through a narrow gorge—in one place only 51 ft. wide— and over three successive falls, altogether 265 ft. The obstructed part of the river is about 190 m. long, and consists of a series of rapids above the falls and a deep canon with whirlpools for some distance below. The Brazilian Government has built a railway around these falls from Piranhas (151 ft. elevation) to Jatoba. (978 ft.) with an extension of 71 m.
Above Jatoba there is another series of rapids, called the Sobradinho, nearly 90 m. above the lower rapids, which are navigable at high water, and above these an unobstructed channel for light-draught river boats up to Pirapora, a little above the mouth of the Rio das Velhas, a distance of 984 m. Here the
river runs through a barren, semi-arid region, sparsely settled. The rapids of Pirapora are 17 miles above the mouth of the Rio das Velhas, and this point, the head of navigation on the river, and 1,742 ft. above sea-level, is the objective-point of the Central do Brazil railway, the purpose being to create by rail and river a central route from Rio de Janeiro to the northern ports of Bahia and Recife.
The principal tributaries of the S5,o Francisco are: on the right, the Path, Paraopeba, Velhas and Verde-Grande; on the left, the Indaya, Abaete, Paracatu, Urucuya, Carinhanha, Cor rente and Grande. Several of these tributaries are navigable for long distances by small boats—the aggregate being a little over r,000 m. Some authorities give the aggregate navigable channels of the Sao Francisco as 4,350 m. The upper valley of the Sao Francisco is partly forested, has a temperate climate, with a mean annual temperature of 85° F and a rainfall of 1,637 milli metres. The rainy season is from December to March, but on the lower river there are sometimes droughts covering several years.
An admirable description of this great river is given by Richard Burton in The Highlands of Brazil (1869), and a more technical description by E. Liais in Hydrographie du Haut San-Francisco et du Rio das Velhas (Rio de Janeiro, 1865).