Shuckburgh equatorial refracting telescope, 1791

Shuckburgh equatorial refracting telescope, 1791. Sir George Shuckburgh commissioned this telescope from the famous London instrument maker Jesse Ramsden (1735-1800) in 1781 but it was only completed ten years later. It is the world's first example of a large equatorial telescope, namely an instrument mounted for making accurate measurement of the position of the stars and planets. The telescope has a lens of 4.1 inch (104mm) aperture and is carried on an equatorial mounting made of tapered brass tubes. Though designed for angular measurement, the mounting of the telescope proved too flimsy and was little used despite later improvements. The instrument was finally dismantled and donated to the Science Museum in 1929. ©SSPL/Science Museum