The pneumatic tube mail system of New York City, in operation from 1897 to 1953, used compressed air to transport millions of letters through an underground network of tubes. Initially praised for its speed and efficiency, the system was eventually discontinued due to high operational costs and the rise of alternative transportation methods like trucks. Despite attempts to revive it by installing fiber optic cables in the tubes, most remain unused beneath the streets of New York today. This system is a fascinating example of a technology once seen as the future, but ultimately overtaken by time.