Joseph Bonomi the Younger into debt and was eventually happy to accept a modestly paid commission to accompany Robert Hay on an expedition, via Malta, to Egypt in 1824. This began a lifelong interest in Egyptology. From 1824 to 1826, he was a member of Hay's expedition where he sketched many antiquities. At Abu Simbel in 1825, Bonomi – responding to Hay's demands for great accuracy – devised a drawing frame (a viewfinder-type device equipped with a sight and a string or wire grid) to help them draw the temples' interior decorations. The expedition then moved on to Kalabsha, where Bonomi laboured to produce
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