New York's tiny air shafts provided a bit of light and ventilation, but they were also convenient dumping grounds.
We have shown this photo on TreeHugger for many years, usually while extolling the virtues of natural ventilation. I wrote that, "in New York, even the cheapest tenements were required by law to have natural light and ventilation to kitchens and bathrooms. Sometimes it might be little more than a slot, but those were the rules." Because the shafts got so tight, there was a stack effect that caused air circulation through the apartment. I thought this was a good thing, that a little bit of light and air was better than nothing.
Maybe not. Cait Etherington at 6sqft points out that, "rather than create a source of air and light, these narrow slots quickly evolved into sources of disease, noise, and dysfunction."
In an age when indoor plumbing and other modern conveniences were still scarce, especially in tenements, the air shaft was adopted as a convenient place to dump everything from food scraps to human waste, and from all accounts, the accumulation of waste was great. A 1885 article in the New York Times reported that when Mary Olsen, an Irish immigrant distraught about her husband’s late-night habits, attempted to jump to her death via her tenement’s air shaft, the garbage at the bottom was so copious, she escaped unharmed from the suicide attempt.
A commission studying tenement housing in 1900 found that the "the ‘air shaft’ was the most serious evil of the present tenement.” In 1901 the regulations were changed to make larger courtyards, big enough for garbage storage and removal, and hanging of laundry.
Perhaps I should add a footnote to all those related posts below where I go on about the wonders of natural ventilation from air shafts.