STANISLAW I: (1677-1766) Stanislaw Leszczynski. King of Poland and Grand Duke of Lithuania 1704-09 & 1733-36, father of Marie Leszczynska, Queen consort of France 1725-68 as spouse of Louis XV. Rare and fine L.S., Stanislas Rex, one page, 4to, Lunéville, 14th February 1754, to Monsieur de la Condamine, in French. Stanislaw I thanks his correspondent stating `I will never thank you enough for the supplement of the historical journal related to your trip to the Equator which you have sent to me. I have instructed to read to me the main parts which you have marked to me´. The Duke of Lorraine further refers to the unfair objections his correspondent´s work received and says `Your responses have seemed to me very solid. However I am quite angry that you have had to feel compelled to do such work, you who can make such good ones..´ and concludes granting with pleasure his support to La Condamine´s future projects. With blank integral leaf. Small overall, minor age wear and foxing stains, with an extremely small tear to the right edge not affecting the text or signature, otherwise VG £500-800 When the treaty of Vienna recognized Augustus III as King of Poland in 1738, Stanislaw I was allowed to keep his Royal titles and was granted the province of Lorraine for life. He was the last Duke of Lorraine 1733-66. Stanislaw I established his court at Lunéville, the capital of Lorraine in the 18th century, which became a famous cultural centre. Stanislaw I was also an author and philanthropist, and many famous followers of the enlightenment visited his court, including Voltaire, Rousseau, Montesquieu and many more. Charles Marie de La Condamine (1701-1774) French Explorer, Geographer and Mathematician. La Condamine spent ten years in present-day Ecuador measuring the length of a degree latitude at the equator and preparing the first map of the Amazon zone. The expedition drew a great deal of attention in France, as he was a popular writer. The journal of his ten-year-long voyage to South America was published in Paris in 1751.