The Clements Library hosted an exhibition of Mississippi Valley maps arranged for the Mississippi Valley Historical Association (the precursor to the American Historical Association). Following their annual meeting, the maps were exhibited to the public. Among the maps shown were a series of photographic reproductions of the manuscript maps of Joliet, Franquelin, and others located in the Archives de la Marine at Paris. Under Mr. Clements’ instructions, 135 of the most important of these were photographed by a French historian, Abel Doysié, who had become familiar with materials related to American history located in French archives during his long employment by the Carnegie Institution. These photostatic reproductions represented the only copies available outside Paris.
Clements employed Doysié directly to photograph maps using the new technology of the photostatic machine, a camera which could reproduce documents and plans at a 1:1 scale. Although the process could not reproduce the colors of the original, it allowed a reader or researcher access to the content of the original document, at its original scale.