A significant Letter Signed, as French ambassador to Austria, to the Comte de Cessac, Napoleon’s Minister of War, discussing the purchase of provisions and the cost of transporting rice from Trieste to Vienna, and from Vienna to Warsaw. In French. 1½ pages 12 x 8 inches, detailed annotation on receipt, integral blank leaf, in very good clean condition. Vienna, 15 April 1812. Louis-Guillaume Otto (1753-1817), French diplomat. In 1810 he was made ambassador to Vienna, where he negotiated the conditions for Napoleon’s second marriage to archduchess Marie Louise. As a young man, Otto left France in 1779 on an embassy to the new United States of America as private secretary to the chevalier de La Luzerne. While in the USA, he succeeded François Barbé-Marbois as secretary of the legation in May 1785, then served as interim chargé d’affaires twice. He came to know George Washington and the main members of Congress.