Great Forty-Foot telescope

William Hershel's Great Forty-Foot telescope was located in Slough and completed in 1791. It took four years to build, and was paid for by George III, who granted Herschel £4000, or £100 per foot. The mirrors weighed half a tonne. Herschel discovered the sixth and seventh moons of Saturn using the telescope.

The Tenth Doctor described it as "spectacular", though Rose Tyler was less interested. (AUDIO: The Sword of the Chevalier)