How to spot fake scientific instruments

Astrolabe, a form of astronomical calculating device

Source: © Whipple Museum of the History of Science, University of Cambridge (Wh.0305)

Is this a 16th century astrolabe, or a modern-day forgery?

It is, unfortunately, a truism of the art world that wherever there is a demand for valuable collectables, forgers will emerge to exploit that market. Until the 1950s, no one suspected that this might be as true for antique scientific instruments as it was for old masters. But in 1951, following the opening of the Whipple Museum of the History of Science in Cambridge, UK, a new form of comparative analysis quickly dispelled this naive assumption.