Topic summary
Transit circle
Extracted from the Wikipedia article Meridian circle.
19th century
The making of circles was shortly afterwards taken up by Edward Troughton, who constructed the first modern transit circle in 1806 for Groombridge's observatory at Blackheath, the Groombridge Transit Circle (a meridian transit circle). Troughton afterwards abandoned the idea and designed the mural circle to take the place of the mural quadrant.