William Herschels 17381822 reflecting telescope with focal length of 40 feet 12.19m, showing top of brick foundation and wheeled platform on which the instrument mounted. Slough, England. Engraving 1809. Editorial Stock Photo - Afloimages
William Herschel's (1738-1822) reflecting telescope with focal length of 40 feet (12.19m), showing top of brick foundation and wheeled platform on which the instrument mounted. Slough, England. Engraving 1809.