Bürosonne copier (1930s)

Hello everyone.

I want to show a old German copying device, the “Bürosonne”, that in German means “office sun”.
It has a powerful lamp, and it's like copier, but it's from 1930s, when copiers didn't existed already. It seems very strange that in the 1930s there was already a photocopier, but here it is.

It works with 220 volts, same as today in Europe. Inside there is also a fan with an air ducting system for cooling.

To print a copy, you cannot use normal paper, the copy must be printed on special photosensitive paper, that exposed to the light created the copy.
You have to prepare the original copy to be copied on transparent paper.

After exposing to the light, you have to use ammonia vapors to prepare the copy. A quite complicated procedure.

If you want to see how it works this device, you can see this video.