Observatories that I have visited:
the Astrograph at
Stockholm's "new" Observatory, Sweden

Content:

1. Introduction
2. The excursion to Saltsjöbaden
3. Historical background
4. What is an astrograph?
5. Optical performance
6. Finder telescope
7. Tracking and motor operation
8. Object tracking, finder telescope
9. The elevator
10. The Dome
11. Glass plates (film)
12. What research was done with this astrograph?
13. Who has worked on this astrograph?
14. How it ended?

3: Historical background

Far back in time the observatory was placed at the Observatory Hill at Odenplan of city Stockholm (capital city of Sweden), where it had been since 1753. At 1920s they realized that light pollution was too bad to continue to operate here. A decision was taken to move out from central Stockholm to Saltsjöbaden, about 20 km southwest of Odenplan.

• https://en.wikipedia.org/ wiki/Observatorielunden (Observatorielunden, Wiki)

Knut and Alice Wallenberg Foundation contributed a great donation, which was an important part of the observatory to come. The inauguration of the new observatory in Saltsjöbadens took place in 1931. The hill where the observatory is located has the name Karlsbaderberget. A big advantage of Saltsjöbaden was of course the proximity to City of Stockholm for the sake of transport. With today demands, however, were never chosen a place like Saltsjöbaden to build an observatory on, not even with the light conditions that prevailed in the 1930s.

• https://www.wallenberg.com/ kaw/en/foundation/ knut-and-alice-wallenberg-foundation (Knut and Alice Wallenberg foundation)

The instruments that were at the old observatory at Odenplan was outdated and only a few were moved over to the new observatory at Saltsjöbaden. The instruments were placed in meridians house, which today is called "Radio building", a building that stands today to the club STAR's disposal. The construction of the new observatory was started in the end of 1920s, among the major new instruments that were purchased and buildings erected was a one meter reflecting telescope, one double refractor and the astrograph. Long later in the 1960s they adding an one meter Schmidt telescope.

First entrance in the astrograph building, concrete pillar as the astrograph is anchored in glimpse in the dark.

Do you see such a sign in front of you, you can be sure that it is something expensive!

• https://en.wikipedia.org/ wiki/Carl_Zeiss_AG (Carl Zeiss, Wiki)

The astrograph in all its splendor, it's the big white tube at the bottom.

Over the main tube is the finder telescope and to the right one of the many counterweights as necessary to balance the instrument. Notice the beautiful domed ceiling in wood.

The instruments were purchased was considered to be of the highest quality, better could not be purchased! Sweden was recognized as very skilled in research of astronomy area already at the old observatory, now at the new with modern equipment it would be even better. The astrograph was ordered from the renowned German manufacturer Carl Zeiss, they belong even today the elite when it comes to optics design. You've probably seen their name on any modern digital camera's optics. The sum paid for instruments and dome were 137,750 Reichsmark, this was before World War II and the production took place during the years 1928 to 1929. I called up the Riksbank in Sweden to get an idea how much money this would meet today (in 2007). From the information service where I was told that 137,750 Reichsmark today would be equivalent to more than 0.3 million Euro, that money don't give you very much today. This was only for the astrograph, the other instruments with their buildings were probably significantly more expensive.

Luxury, a window, you will find it hardly in a modern observatory.