The Greek expertise

There is also, of course, the Greek expertise at astronomy and mathematics, and ingenuity in constructing machines to match that expertise: Ptolemy describes the construction of an astrolabe, an instrument for measuring the positions of the stars; and a little machine with geared wheels, discovered in the sunken wreck of a vessel of the 1st century BC, seems to have been devised to work out the motions of the planets. If some Greek ideas about the constitution of the solar system were distinctly eccentric (Ptolemy’s not least so) their grasp of mechanics and mathematics was brilliant — much more so than many historians of the 18th century believed.