Subterranean Velocity: The Pneumatic Veins of Early Metropolises

Long before fiber-optic cables pulsed with digital data, the great cities of the world communicated through a massive, roaring labyrinth of pressurized brass tubes hidden just beneath the cobblestones. It was a time of rapid industrial growth, and the pace of communication was struggling to keep up. As nineteenth-century commerce exploded, the physical delivery of telegrams and stock market upda...