Observing a solar eclipse, 1673.
© Science Museum / Science & Society Picture Library
Two men are projecting the eclipse onto a screen. Plate from 'Machina Coelestis' (1673) by Hevelius. Johannes Hevelius (1611-1687) was a German astronomer. He established the foremost observatory there in 1641 and built another when the first was burnt down in 1679. He catalogued 1500 stars, discovered four comets and was one of the first to observe the transit of mercury.