The Hubble Space Telescope (HST), c 1980s.

Equatorially mounted refracting telescope with dome, 1914.

Casegrain reflecting telescope, 1762-1774.

Cassegrain reflecting telescope, 1762-1774.

Warren de la Rue's 13 inch reflecting telescope, 1858-1864.

James Nasmyth using his 20-inch reflecting telescope, 1850-1870.

Heliostat, c 1752.

Optical telescope asembly of the Hubble Telescope, 1980s.

Model of the Great Melbourne telescope, Australia, 1876.

William Herschel's 40 foot telescope at Slough, Berkshire, 1795.

Early photograph of William Herschel's telescope at Slough, 1839.

Dall-Kirkham reflecting telescope, 1960-1975.