One of two colour engravings (Pl.15) with window mounts showing colour sketches of four captioned lunar craters, Agatharchides, Hypatia, Guttemberg & Julius Ceasar, observed and drawn by Etienne Leopold Trouvelot in 1872.

Lithographic colour print issued by Harvard College Observatory in 1876, showing four sketches of craters on the Moon (Agatharchides, Hypatia, Guttemberg & Julius Ceasar). Produced in 1872 by Etienne Leopold Trouvelot (1827-1895), a French artist, these views were produced using the observatory's 15-inch refracting telescope made by Merz of Munich, Germany. At this time, drawings made at the telescope using only the eyes showed more detail than could be produced using the insensitive photographic films then available.