The Observatory collection includes many objective lenses and mirrors of early telescopes used at the Cape. The top shelf carries a Ross lens and a Dallmeyer that were used during the first years of Astronomical Photography at the Cape. The second shelf contains an early plate camera and several 19th-century camera lenses, as well as some other photographic items. All early astronomical photographs were taken on glass plate negatives. The third shelf has a mirror made by Sir William Herschel for a reflecting telescope. The bottom shelf has a historically important mirror made by Sir John Herschel and used during his survey of the Southern skies from the Cape.