Collection of Lithuanian-German photographer's (1896-1964) photographs of the men, women, and children who worked in the Bolivian mines of the early 20th century. The photographs were discovered in 2010, nearly a century after being taken, in the Chilean Biblioteca Central of the Universidad Católica del Norte in Antofagasta. The book by French anthropologist Pascale Absi and sociologist and historian Jorge Pavez portrays part of boom of the "tin barons" (some of the richest men in South America like Patiño, Aramayo and Hochschild) in Bolivia between 1925 and 1936, comprising images reproduced in the highest quality, with all corresponding information by Gerstmann, and organized into a body of work that respects the passage of time and geography as experienced by the photograher and his subjects.