Image: Unique pneumatic tube photo
This photo is a new print from an early 1900's glass "magic lantern" slide. I think it is a unique one, because it shows three types of transportation in one shot.
The man on the photo is sending a carrier in a pneumatic tube station manufactured by the Mix & Genest company, which is probably connected to the Berlin pneumatic city mail system (Stadtrohrpost). I conclude this from the title of the slide "Rohrpost für fernbetrieb", translated: long distance pneumatic tube system.
At the left and right side of photo you see a pneumatic tube station for internal building transportation (Hausrohrpost).
And last but certainly not least, at the ceiling of the room there is a cash carrier wire system.
Mentioned at the slide:
"Verlag Dr. Franz Stoedner Berlin NW7
Wissenschaftliche Projektion und Stereoskopie
Rohrpost für fernbetrieb"