Johann Rudolph Rengger (January 13, 1795 - October 9, 1832) was a Swiss naturalist and doctor. He is best known for his books pertaining to his exploration of Paraguay. Having received an education as a doctor and natural scientist in Switzerland, he spent the years between 1818 and 1826 in Paraguay, his intention having been to undertake a research trip with colleague Marcel Longchamp, in order to document the natural history of the country. The two immediately became entangled in the politics of the region. They first endured a delay of eight months in Corrientes due to the river blockade by the United Provinces of the Rio de la Plata under José Gervasio Artigas. After finally reaching Paraguay - then ruled by 'El Supremo,' the dictator José Gaspar Rodríguez de Francia - they found their every move supervised by government officials. While Rengger avoided arrest as a spy (as occurred with French botanist Aimé Bonpland) the two were not allowed to cross the border, and required special permits for every excursion they made. In addition, Rengger and Longchamp were virtally isolated from the rest of the world, as indeed was all of de Francia's Paraguay: 'El Supremo' blocked most of Rengger's mail. When the two eventually obtained an exit permit in 1825, they were allowed only a few hours to prepare for the journey, and had to leave without most of their collections. This ejection from Paraguay finally saw the pair's return to Europe. In Paris, Rengger began to compile his research, only to find that his European audience was little interested in Paraguay's flora and fauna, but powerfully curious about the country's dictator. Therefore Rengger first published, instead, his historical essay on the Paraguayan revolution and the dictatorship of Francia: the book was printed in 1827. Excerpts published in the Stuttgarter Morgenblatt reached the dictator, and goaded him to rebut the work. Only after this political foray did Rengger complete his natural history. Further descriptions of his journey were cut short by Rengger falling ill with pneumonia, an illness which would ultimately take his life. More by this mapmaker...

Azara, Félix de (May 18, 1742 - October 20, 1821) was a Spanish military officer, naturalist, and engineer. He joined the Army, and received training as an engineer in a Spanish military academy. His thirteen year career in the Army would see him promoted to Brigadier General. He spent twenty years in the Rio de la Plata region of South America as a delegate under the treaty of San Ildefonso, during which period he undertook to create an accurate map of the region. On the surveys, he also recorded the fauna the region, in particular cataloguing nearly four hundred species of bird. On his return to Europe in 1801 he wrote and published in Paris his Voyage dans l'Amerique meridionale depuis 1781 jusqu'en 1801 (1809) which contained his observations on the region's geography, natural features, and indigenous groups. His work was praised for thoroughness and accuracy, and was well regarded by Darwin. He died of pneumonia on October 20, 1821. Learn More...

L. H. Berthe (fl. c. 1777 - 1830) was a French engraver active in Paris in the early to mid-19th century. Little is known of Berthe. He seems to have been active as early as 1777 and as late as 1830. He maintained offices at Rue St. Jacques , No. 66. Learn More...