FOURIER JOSEPH: (1768-1830) French Mathematician and Physicist. Best known for initiating the investigation of the Fourier series and their applications to problems of heat transfer and vibrations. The Fourier transform and Fourier´s law of conduction are named after him. He is credited with the discovery of the greenhouse effect. Rare L.S., Fourier, one page, folio, Cairo, 21^st December 1799, in French. The letter being a report of state of expenses issued by the Commission of Information related to the modern state of Egypt. Signed by Fourier in his capacity as President of the Commission.The document details a small list of expenses with their individual cost, stating `Achat de neuf cartables… achat de deux registres…. Achat de diverses drogues pour faire de l´encre… faire relier un livre Arabe …´ (“Purchase of nine binders… purchase of two registers…. Purchase of various drugs to make ink… to bind an Arabic book..”) Also signed, twice, by Baudeuf, a French important representative of an important company of commerce at Cairo, in his capacity as Secretaire of the Commission. Overall age wear, mostly to edges, with very slightly trimmed edges. G