Between May 1885 and December 1886, Gaston Maspero and Richard de Régnauld de Lannoy de Bissy exchanged at least four letters, concerning a map, de Bissy had apparently made of Egypt and that Bissy wanted to have presented to “Doctor Schweinfurth” (Probably Georg Schweinfurth).
Here is a Letter from May 16th, 1885.
Boulaq, May 16th, 1885
I am sorry to report that I have not been as successful in my enquiries as I had wished. The Ministry of Public Works which I contacted has still not replied to me. Schweinfurth is away for a few days. But I still hope to succeed in obtaining the information you need.
We could maybe find it directly in France. The map of the Fayum was made about ten years ago by a Frenchman named Rousseau who has left the Egyptian Service and has returned to France.
In 1884, his last address was Rousseau-Pacha, former under-secretary of State at the Ministry of Public Works, at Cannes.
I believe he has recently moved to Versailles but if you write to Cannes, the letter will almost certainly be forwarded to his new address.
Source of the Letter: Bibliothèque nationale de France
Translation: Sylvie Weens