The Helsinki University Astronomical Observatory started operation in 1834. Its collections were older than that, as it had inherited astronomy collections from the Turku Academy, founded by Queen Christina of Sweden in 1640. After Finland became a Grand Duchy of Russia, the university was moved to Helsinki. A big part of the Academy library collections were lost in the Great Fire of Turku in 1817. Astronomy collections were safe as the fire never reached Observatory Hill.
The Observatory suffered no major upheavals in its 175 years of operation (1834–2009) that followed. The library acquired quite extensive collections. The observatory was full of old instruments, manuscripts, separata, books, photographic plates, maps, exchange collections, reprints, staff publications, journals, ephemerides, and so on. When the emptying of the Observatory started in 2009, there were over 800 shelf meters of library and archival materials – and maybe more, if one counts boxes found in the attic.
Where did everything go? There were a few major outside takers. The oldest books (1600s–1830s) were deposited to the Finnish National Library, along with the ’separata’ collected by the astronomy professors from late 1600s on. The University of Helsinki Central Archives took manuscripts. Books and journals already held by the Kumpula Campus Library were sent to the National Repository library in Kuopio. Other takers included the Tuorla observatory of University of Turku (Russian language books), Finnish Horological Museum (books and journals on clocks) and the Department of Physics (reprints of department of astronomy publications). For a more detailed description of the process, see \cite{2012wgl..conf...75I}.
The Observatory library was the last department library at the University of Helsinki to be merged. In 2009, there was barely enough space left at the Kumpula Campus Library to accommodate the collections arriving from the Observatory. A large part had to be put into more or less expensive remote storage as a temporary solution. The collection of exchange publications from other observatories (some 200 shelf meters) has been in remote storage for 4 years. At the time of writing, this collection is due to another relocation and faces a uncertain future.
Kumpula Campus Library only took the so-called active collections, and the older books (1830s–1940s) – not old enough for the Finnish National Library – were deposited at the Observatory, now renovated into a visitor centre and a museum. It is hoped that the presence of these books at the Observatory will give the visitors – mostly school children – the message that astronomers needed more than just instruments, but also literature to do their research.