The site mentioned above refers to the stench of the stock yards. Any city in those days must have had a miasma that would clear your sinuses pretty fast, especially in the summertime.
I was a kid in NYC in 1948 when they still had a few horse-drawn delivery carts and things would be pretty pungent until the street sweeper came by - a guy with a wide brush and a trashcan on wheels.
How do we see the whole twelve minutes???
I used to work with some guys who were kids in Brooklyn, NY, around 1911.
They told me how they used to play in the streets and pick up horse manure to throw at each other.
Sounded gross to them when they told the story as old men.
But horse manure from a healthy horse really isn’t bad—I had no problem picking it up with my bare hands and never bothered altering my course to avoid stepping in it when I spent a lot of time around horses.
Horse manure is like high quality fertile earth.