2-701-073 - Historica Graphica Collection/Heritage Images

Herschels Grand Telescope, (Fig. 24), Plate 505 from Encyclopaedia Britannica , pub. 1797 (engraving). Herschel's 40-foot telescope was built between in 1785 and 1789 at Observatory House in Slough. It was a reflecting telescope and was dismantled in 1840; Sir Frederick William Herschel (1738 - 1822).