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 goddesses Hathor, Isis, Maat, Mut of Asher, Satis and Taweret; in one scene Ramesses is presenting flowers or burning incense. The capitals of the pillars bear the face of the goddess Hathor; this type of column is known as Hathoric. The bas-reliefs in the pillared hall illustrate the deification of the king, the destruction of his enemies in the north and south (in this scenes the king is accompanied by his wife), and the queen making offerings to the goddess Hathor and Mut. The hypostyle hall is followed by a vestibule, access to which is given by three large doors.