Astronomical chair
The Astronomical chair or observers chair is or was for observatories with large telescopes on high telescopic columns of help to the Observer , with the eye or with measuring instruments to the eyepiece get hold of the telescope.
It is a combination of ladders in the form of a 3–10 meter high inclined elevator , with which the observer can use a cable pull to bring himself to the appropriate height on a chair-like seat .
In the giant telescopes of the turn of the century, which reached lengths of 10 to 20 meters, the mechanics of the observer chairs were improved so that the astronomer could pull himself up with an effort of about a quarter of his body weight ( it was much easier to go down ). Occasionally there was also an electric drive, which gave the constructions the humorous name " electric chair ".
From around 1910 onwards, the astronomical chairs were replaced by lifting platforms , which, thanks to 4 thick threaded spindles and counterweights, allowed a smooth vertical movement. For example, the main dome of the Vienna University Observatory was equipped with such a lifting platform in 1930; With a diameter of around 14 meters, it takes up most of the cross-section of the observatory dome .