Théodule Devéria help Mariette read inscriptions in Cairo and its surroundings. He tried to accurately document the archaeological sites using drawings, stampings and photographs. His calotype pictures from this trip are often poor in quality, showing a lack of technical skills. In 1860 he was appointed preserving assistant at the Louvre's Department of Egyptology. He revisited Egypt in 1861–62, traveling up the Nile to Philae at the First Cataract, and into Nubia to the Abu Simbel temples. After returning he helped Mariette prepare descriptions of the excavation in Egypt in 1850–54 for publication. In November 1864 Devéria met the future oriental scholar
Abu Simbel temples the small sanctuary represent scenes of offerings to various gods made either by the pharaoh or the queen. On the back wall, which lies to the west along the axis of the temple, there is a niche in which Hathor, as a divine cow, seems to be coming out of the mountain: the goddess is depicted as the Mistress of the temple dedicated to her and to queen Nefertari, who is intimately linked to the goddess. Each temple had its own priest that represents the king in daily religious ceremonies. In theory, the Pharaoh would have been the only celebrant