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 a way that on October 22 and February 22, the rays of the sun would penetrate the sanctuary and illuminate the sculptures on the back wall, except for the statue of Ptah, a god connected with the Underworld, who always remained in the dark. People gather at Abu Simbel to witness this remarkable sight, on October 21 and February 21. These dates are allegedly the king's birthday and coronation day, respectively. There is no direct evidence to support this. It is logical to assume, however, that these dates had some relation to a great event, such as the jubilee celebrating