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 ancient human civilization were under threat from the rising waters of the Nile that were about to result from the construction of the Aswan High Dam. One scheme to save the temples was based on an idea by William MacQuitty to build a clear fresh water dam around the temples, with the water inside kept at the same height as the Nile. There were to be underwater viewing chambers. In 1962 the idea was made into a proposal by architects Jane Drew and Maxwell Fry and civil engineer Ove Arup. They considered that raising the temples ignored the effect of