Ellen Mitchell, age 13, of Harrisburg, Pa. for her question:

WHEN WAS THE FIRST ESCALATOR USED?

Escalator is the common name for a mechanical contrivance in the form of a moving stairway, the steps of which ascend or descend, carrying passengers from one floor to another. The earliest type of escalator, patented in 1891 by a man named Jesse Reno, was an inclined  conveyor belt.

At about the same time, an American inventor named Charles Seeberger developed a similar device with horizontal steps, which he trademarked as the „escalator."

In 1900 the Otis Elevator Company constructed the first successful escalator and exhibited it in Paris. It was modeled after Seeberger's invention. The company later combined the best aspects of both the Reno and Seeberger inventions and in 1921 produced an escalator of the type used today.

Design improvements brought the escalator into extensive use in department stores and in metropolitan railroad and subway stations.

Considerations of safety and convenience limit escalators to low speeds today. A rate of about 100 feet per minute is about standard. The carrying capacity is determined by the width of the steps, which is generally either 32 or 48 inches.