Elevators are a relatively recent development because it is only in modern times that multi-story buildings have been built. The first elevator built in 1743, was created to transport the French King Louis XV to every floor in his palace in total privacy. This elevator was operated by hand and counterbalanced with weights.
The modern safety elevator of today was invented by the American Elisha Otis. He demonstrated his elevator in 1854. Its effectiveness was theatrically shown by Otis ordering a rope to be cut. This rope appeared to be the only thing holding up the elevator with him inside. He had devised an emergency braking system which worked immediately as the rope was cut, and therefore prevented the elevator from falling.
The elevator consists of only a few components. The car for carrying people can be either raised or lowered, with the assistance of a cable which runs over a pulley at the uppermost part of the elevator shaft. Joined to the opposite end of the cable is a counterweight, which balances both the weight of the elevator and the additional weight of the passengers. Guide rails are used for the counterweight and car. An electric motor is employed to drive the pulley and maneuver the car. The advantage of using this method is that only a small amount of power is needed to lift the difference of the weight of the car with its passengers.
In modern elevators the use of sophisticated micro-computers controls the logic which ensures each floor of a building is serviced in the most efficient manner. This increases the elevator efficiency and reduces the time and frustration of passengers waiting for the elevator to arrive.
