These two minarets seem to belong to the Mosque of Nebi Daniel (see for comparison a large format view of the same building sold in May 2003, lot 18). This was a building of great historic interest as it was said to have been built over the tomb of Alexander the Great. The present Mosque of Nebi Daniel was built at the end of the 18th century and restored in the 1820s. The minaret is the most visible part of any mosque from a distance and is an architectural form that is universally associated with the Islamic faith. In this view the two towers catch the light and emit a radiance that contrasts with the neighbouring buildings which remain in deep shade.
Girault de Prangey made three or possibly four large format studies of this mosque, describing the sprawling and complex structure from different aspects, but this appears to be the only detail. His other small daguerreotypes from Alexandria are of different subjects (see lots 15, 16 and 26 for examples).