John Flamsteed (1646–1719), the first Astronomer Royal, set up a solar observatory at Greenwich, on the site of the modern camera obscura that can be visited today. His observations were among those studied by a much later Royal Observatory employee, E. Walter Maunder (1851–1928). Maunder showed that there had been an exceptionally low occurrence of sunspots between 1645 and 1715, a period now known as the Maunder Minimum.

Image: Flamsteed’s camera obscura, engraving by Francis Place (A7121-K)