An escalator is a moving staircase which carries people between floors of a building or structure. It consists of a motor-driven chain of individually linked steps on a track which cycle on a pair of tracks which keep the step tread horizontal.
Escalator in a metro station in Warsaw
Escalators at the Christ the Redeemer statue in Rio de Janeiro, Brazil
Illustration from U.S. Patent#25,076: Revolving Stairs, issued August 9, 1859, to Nathan Ames
Macy's Herald Square store in New York City holds some well-known historic escalators. The model shown here, retrofitted with metal steps in the 1990s, is among the oldest of the store's 40 escalators. Otis "L-type" escalators with distinctive wood treads (not shown) have operated in the store since 1927.
An elevator or lift is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive traction cables and counterweight systems such as a hoist, although some pump hydraulic fluid to raise a cylindrical piston like a jack.
Outside of typical elevators, shown in an office building in Portland, Oregon
This elevator to the Alexanderplatz U-Bahn station in Berlin is built with glass walls and doors, exposing the inner workings.
Elevator design by the German engineer Konrad Kyeser (1405)
Elisha Otis demonstrating his safety system, at the New York Crystal Palace, 1853
