Over a century before the Hyperloop was a sparkle in Elon Musk's mind, a revolutionary series of high-tech pneumatic tubes shot capsules of mail around New York City - just feet below the bustling sidewalk.
A fascinating, if arguably overlong, look at one of the Internet’s precursors — London’s 19th-century system of pneumatic tubes. It was a quicker way to transmit telegrams within the city, and eventually included 85 miles of tubes, pushing cylinders with messages using compressed air. There is talk of using them today, since the system is more secure than a digital network. —Quentin Hardy, Deputy Technology Editor