It’s a river of slime! There’s gotta be 25,000 gallons of it! It’s flowing through here like a river! Van Horne! Pneumatic transit. I can’t believe it! It’s the old pneumatic transit system! It’s still here!
– Ray Stantz (Dan Aykroyd)
The pneumatic subway line that Ray finds when they lower him below the street was based on a pneumatic line built in 1870 by Alfred Beach. It operated using compressed air and was built as a demonstration of a pneumatic transit system. The one-block-long tunnel was built prior to any other subways in the area and without any City approval. It had a single beautifully appointed station adorned with frescoes, easy chairs, statues and a goldfish pond. The line was shut down in 1873 due to lack of official and financial support. The tunnel entrance was sealed and the station was reclaimed for other uses. In 1912, when digging for the modern subway system, workers found the original tunnel, still in good condition, and the remains of the passenger car. The tunnel was removed to make way for the contemporary subway lines and the passenger car has disappeared into history. Today there are no physical remains of Beach’s experimental and ambitious subway project.