Identify.

Horologium, Gnomon brought to Rome in 10 CE, obelisk from Egypt, taken from Heliopolis originally erected by Psammetichus II in the 6th cent BCE, now in Piazzo del Parlimento, turned into a sun dial, casts a shadow on the pavement, shadow would fall on Ara Pacis on Augustus's birthday (Sept 23), elements of Greek influence (Greek markings on pavement for sun dial), imagery of his victory over Egypt