RIEZNIK, Marina Los cielos del sur. Los observatorios astronómicos de Córdoba y de La Plata, 1870-1920 (The southern skies. The astronomical observatories of Córdoba and La Plata, 1870-1920), Prohistoria Editiones, 2011 - Col. Historia de la Ciencia, 4-220 pp.This book describes and analyzes the work performed at the observatories of Córdoba and La Plata since their foundation (in 1871 and 1882 respectively) to the 1920. Marina Rieznik’s analysis follows open perspectives in the historiography of science according to which the political speeches are not a central reference of scientific development, but politics is one of the analytical approaches that should be combined with analysis of the tools, the spaces and the products of the observatories, parliamentary debates and the approaching that made the press of the period about their historical existence . ... southern skies…, extended by António Augusto P. Videria, demonstrates how adopting an original key of reading, the history of these two Argentine observatories is crossed by international conflicts that are detectable in a very concrete way in the materials, products, processes, spaces and characters analyzed.