Carriage of the Iquique - Puerto Hundido Railway at Oficina Salitrera Humberstone. The saltpetre works was built by the Peruvian Nitrate Company under the name of La Palma. Towards 1877 it produced nitrate with the Machine System. In 1890 the Shanks System was implemented, by which the raw â€œcalicheâ€ from the pampas was ground and dissolved in water at high temperatures resulting in concentrated nitrate salt. The plant was taken over by CompaÃ±Ãa Salitrera de TarapacÃ¡ y Antofagasta in 1933, which restructured its productive facilities, modernized its camp and renamed it Santiago Humberstone, in honour of a prominent English chemical engineer. It reached its maximum expansion in the 1940s with a population of 3,700 inhabitants and ceased operations permanently in 1960.