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
Egyptian temple from the distorting effect of additional construction. Many temples, known as hypogea, were cut entirely into living rock, as at Abu Simbel, or had rock-cut inner chambers with masonry courtyards and pylons, as at Wadi es-Sebua. They used much the same layout as free-standing temples but used excavated chambers rather than buildings as their inner rooms. In some temples, like the mortuary temples at Deir el-Bahari, the processional path ran up a series of terraces rather than sitting on a single level. The Ptolemaic Temple of Kom Ombo was built with two main sanctuaries, producing two parallel axes that run