The line is said to be paying its way, but its success depends very largely upon the fate of Amazonian rubber in world markets. With the price of “hard fine” reduced by the competition of the rubber of Eastern plantations, it is difficult to see how freight rates over the railroad can be maintained at the present very high scale, necessary in order to give a return on cost; and, rich as the tributary country is in drugs, dyes and hardwoods there would have to be a great deal of development in production before the place of rubber could be filled. It will be extremely regrettable if this remarkable line, a band of steel in the middle of a country of deep wild forests cannot succeed financially: it is one of the world lines which are life as well as time savers, for before its inauguration the annual loss in the falls of both freight and men was twenty-six per cent.[10] [Illustration: Porto Velho, Madeira River, in construction period of Madeira-Mamoré Railway. Igarapé of S. Vicente, Manáos. ] Another line whose _raison d’être_ is the necessity for avoiding falls on a river is the Estrada de Ferro Paulo Affonso, on the S. Francisco river, extending from the port of Piranhas in Alagôas State to Jatobá, in Pernambuco territory; the line is one hundred and fifteen kilometers long, runs on the left bank of the river, and serves as a carrier for the raw material and output of the big cotton-spinning mill (_Fabrica da Pedra_) recently established. The factory obtains power from the tremendous Paulo Affonso Falls, about thirty miles distant, and several plans have been made to convey force to Bahia city, dependent upon imported fuels for generating motive power. The third interior, river-serving little strip of railroad is in the State of Maranhão, running from Therezina on the Parnahyba river, boundary with Piauhy State, to Caxias; the fourth is a line in the interior of Pará, and is still under construction although about fifty kilometers are in operation. It runs from Alcobaça on the Tocantins river past a series of troublesome runs and cascades to the Praia da Rainha, near the junction of the Tocantins with the greater Araguaya.