Organized by historians Lorelai Kury and Magali Romero Sá, of the Casa de Oswaldo Cruz (COC/Fiocruz), the book provides an overview of the Rondon Commission, comprising texts signed by ten multidisciplinary experts, accompanied by a valuable photographic collection of the period, as well as manuscripts, books, maps, anthropological / ethnological reports, botanical drawings, and watercolors. The authors study the trips and activities commissioned by the Mato Grosso telegraph company Linhas Telegraphicas Estrategicas de Matto-Grosso ao Amazonas (CLTEMTA, 1907-1915) carried out by Brazilian military engineering and construction sector of the army in the mission/expedition lead by Coronel Candido Mariano da Silva Rondon from 1900-1930. This book includes photographs of Theodore Roosevelt whose scientific expedition in the Amazon joined that of Rondan for some time. One of the results, (pictured in the volume), is a Rio Roosevelt in the middle of the Amazon (formerly the River of Doubt).