Zeiss reflector telescope
Here we see the largest telescope of the Historical Observatory with a mirror diameter of 40 cm, a focal length of 100 cm and a weight of several tons. It was one of the first telescopes manufactured by the Zeiss company and was installed in the newly built observatory in 1905. This made it not only the most light-sensitive telescope of the Habsburg Empire, but also the first large reflector telescope in the monarchy.
In the decades before, exciting inventions had been made that brought about a huge change in astronomy: For thousands of years, astronomers had only been able to measure the positions of stars and planets and record what they saw by hand. The invention of photography in the second half of the 19th century made it possible for the first time to capture the sky on photographic plates.
The possibility of not only measuring the positions of the stars but examining them spectroscopically was also completely new. This involves splitting their light into the individual colors and capturing them on photographic plates, which allows us to obtain information about the temperatures and chemical compositions of the celestial bodies.
The new techniques could be used with this telescope. It could be aligned in all directions and automatically followed the stars as they moved across the sky with the help of a built-in clockwork mechanism. However, to ensure that the photos, which were exposed for up to an hour, were sharp, one had to look through the eyepiece of the long guide telescope on the left-hand side and make sure that a selected star always remains in the crosshairs.
In addition to the large main tube, in which the 40 cm mirror and the mounting bracket for the photo plate are situated, other smaller telescopes can also be seen. They were used for specific tasks.
