ハンブルク天文台
The Hamburg Observatory-Bergedorf location had a 60 cm (~23.6 inch) aperture Great Refractor by Reposold and Steinheil (Lenses). One unique feature of Hamburg Great Refractor is Iris diaphragm that allows the aperture to be adjusted from 5 to 60 cm. This telescope was activated in the early 1910s.