Autograph letter in English, 1 page from the French mathematician, statistician and engineer Charles Dupin [1783-1873]. Gifting a speech to his correspondent (not present). The letter is dated 1828. An obituary of Dupin is attached to the top left-hand corner of the letter. The letter itself is glued at each corner to an old album page. The clipping is also glued. Good condition, envelope folds.