This chemical product, which we call Chilean saltpetre, and which is locally known as _salitre_, is found over hundreds of square miles of territory. The only visible boundaries between the different owners are marked by white posts at the corners of the different properties. With this exception there are no marks whatever on the landscape, and no signs of life except the factories, known as _oficinas_, the numerous homes of the employees made of corrugated iron, and the workmen who are engaged in blasting and hauling away this mineral. The nitrate beds follow the coast line at a distance of from fifteen to a hundred miles from the sea, generally at an elevation of from four thousand to five thousand feet, and in deposits which vary from one to four miles in width. They reach from near Antofagasta to a point some distance north of Iquique. In some places the deposits play out, but they reappear again a little farther on. The fields that have been exploited look as though they had been ploughed over by gigantic ploughs, for immense clods are scattered here and there wherever the work has been carried on. On either side of this strip there is simply a mass of sand and rock, which extends from the sea to the topmost peaks of the Andes. There is, however, a wonderful colouring on the slopes of the mountains, and one will see many tints of violet, green, lemon and gray within the horizon. Nitrate of soda is seldom found pure, and the nitrate rock, called _caliche_, will vary from ten to sixty per cent. of the pure mineral. In some fields it is found on the top of the soil, and in others it is as much as forty feet beneath the surface, with the strata of salt rock on the top of it. It varies considerably in composition. Holes are dug or drilled down through the _caliche_ until a bed of gravelly material is reached, into which charges of dynamite or blasting powder are placed, and the nitrate rock is thus loosened up. When first exposed the nitrate is sometimes as soft as cheese, but it hardens on contact with the air. The lumps thus broken are then dug out with picks or crowbars and hauled in mule-carts to the _oficinas_.