The Secret History of the St. Louis Post Office and Its Amazing Pneumatic Tube
One hundred years ago, subterranean St. Louis was a fascinating place. There was, of course, the web of caves that stretched from Benton Park north to downtown and east to the Mississippi River with detours into neighborhood basements. Before the Civil War, the cave network may have been one of the the last stops on the Underground Railroad before Illinois and freedom, but by the turn of the twentieth century, it was mostly used by local breweries to store beer and was -- and remains -- a subject of fascination for urban explorers.
image via A tube room in the basement of a post office. It's unclear where this particular tube room was, but if it wasn't in St. Louis, the one here probably looked very similar.
Less well known, maybe because it was too small for people to crawl through, was the system of pneumatic tubes that spirited mail from Union Station to the Old Post Office on Ninth Street and back again.
Pneumatic tubes have, sadly, gone out of fashion, except at drive-through banks, nuclear reactors, Denver International Airport and, allegedly, the British House of Commons, but at the end of the nineteenth century, they were considered cutting-edge technology, an easy way to move money, letters and small packages within buildings. But a few early proponents of pneumatic tubes, including Alfred Ely Beach, the editor of Scientific American in the 1860s and '70s, had much grander ambitions.
In 1867 in New York City, Beach demonstrated an underground Pneumatic Railway, large enough to hold twelve passengers at a time. In contemporary illustrations, it looked pretty steampunk-fabulous.
Sadly, the idea was expensive and never really caught on. Within twenty years, engineers had figured out a way to build trains that ran through a tube underground without producing exhaust that would suffocate the passengers: the subway!
Still, the fascination with pneumatic tubes remained.