 The original main instrument of the observatory, housed in the dome, was a 280 mm refractor with a focal distance of 4.9 m. In 1895, this telescope was replaced by a 360 mm refractor with a focal length of 4.9 m and a 200 mm photographic lens with a focal length of 4.8 m. The purchase of the double refractor enabled the observatory to participate in photographic observations without having to give up visual observations.This double refractor is still found in the dome of the Østervold Observatory, while the 1861 refractor is displayed at the Steno Museum in Århus.c

1862-1875