I took tons of pictures; here are some more. They are mostly of old advertisements for vacuum cleaners. I was incredibly fascinated by the mechanical vacuum cleaners that used no electricity.
When I first saw this ad, I thought, gee, the guy's just sitting there reading a newspaper while his wife is busy vacuuming. How rude! Herr Steffgan told us that this is a patent drawing for a vacuum cleaner that is provided suction by the person rocking back and forth in the chair. Apparently the husband pictured isn't as lazy as I had thought.
Another interesting contraption. The woman creates suction by walking on bellows.
This vacuum is activated by turning the wheel. The photo above it is an ad for this model.
Close-up of the ad.