Window Baby Cages, 1930s
"Enclosed in a wire cage suspended from an apartment window, English children play in the sunlight and fresh air while their mothers are busy with housework. The cage, made of wire netting is strongly braced and is guarded on the apartment side by a cloth net which prevents children from crawling back into the room. Loaned by an infant welfare center to families with no gardens, the portable balcony is apparently popular with children and mothers." —Popular Mechanics (193os) The more I look at this the more I want an adult-sized one for my 10th floor apartment.
Watch a vintage segment on this trend on YouTube. (photographs: Getty; Corbis)