Some of the railways in the Chaco end at the rivers, where the logs are loaded on boats and taken down to Rosario or Buenos Aires. Small sawmills are now found way out in the Chaco far from civilization. Other companies have their factories in the Chaco district, where the whole work is done and the extract prepared for shipment. This substance is known in the markets as “Quebracho Extract.” It is easily manufactured where the proper machinery has been installed. The wood is passed through a machine which cuts it into shavings and the smallest possible chips. These are collected into immense kettles, where it is treated by chemical processes until all the tannin has been removed. After this the fluid is reduced by evaporation to a thick, jelly-like mass which is poured into sacks, where it is finally dried into the substance sold in commerce. Some of the companies engaged in this business have been capitalized for very large sums, and considerable towns have grown up around their establishments. Civilization and development have followed the construction of the railroads here as everywhere. [Illustration: AN INDIAN WOMAN OF THE GRAN CHACO] In 1895 the first exportation of quebracho extract is recorded from the River Plate. In that year it was four hundred tons only. By 1902 it had reached nine thousand tons, and now the annual export exceeds thirty thousand tons. Of this enormous export the United States takes fully sixty-five per cent. There are several thousand Indians who live in the Gran Chaco, and they comprise a number of tribes, all of whom, however, have the same general characteristics. These Indians are absolutely unlettered, and they have developed no civilization or institution of their own. Furthermore, they have the reputation of being treacherous and cruel, and many small parties of whites have been treacherously murdered. They are perhaps the most barbarous of any Indians in South America. Others of the same tribes inhabit the Chaco of Paraguay. It is said by those who have made a study of them that these Chaco aborigines are more ignorant and much less tractable than any of the natives of Patagonia.