COIN-IN-SLOT REVEALS MICROSCOPIC WONDERS (Oct, 1933)
COIN-IN-SLOT REVEALS MICROSCOPIC WONDERS
Aware of the wide-spread interest in wonders of the microscopic world, an ingenious inventor of Oelwein, Iowa, has devised the coin-operated microscope illustrated above. By dropping a penny in a slot, the user may look through the lens at any one of ten subjects displayed on a rotary disk. A printed description of each of the subjects is mounted on top of the case, and the one desired is selected by turning the disk with an outside knob before the coin is inserted. And electric light automatically illuminates the subject.