A mechanical computer is a computer that, instead of running on electricity and electrical parts, uses mechanical parts. Unlike electronic computers, which are able to run themselves because of electricity, a mechanical computer receives power from an outside source: the user. To use this computer, the operator has to continuously pump a crank, perhaps thousands of times, to perform a calculation. This computer is often regarded as the first stage of the modern computer, and it was primarily used until the late 1940s, though there have been some uses since then. While this computer had many varied uses, it commonly was used for calculations, navigation and with missiles and torpedoes during wars.
When someone mentions a computer, he or she often is talking about an electronic computer that runs on electricity and contains many chips and circuits. By contrast, a mechanical computer relies on mechanical parts. Common parts include gears, screws, pulleys and levers, with levers being perhaps one of the most memorable parts because of the loud noise made when operators pull them. Even after the advent of electronic computers, this computer was still built with mechanical parts in keeping with the design aesthetic and benefits of using mechanical parts, such as substantially lower energy needs and better durability.
A mechanical computer does not have an electrical power supply, so it relies on the user to provide power. This is most commonly done through the constant moving and slamming of a lever, which moves the mechanical parts. Simple calculations can be done in several lever pulls, while complex equations can take thousands.
In the list of pre-electronic computer devices, the mechanical computer is often regarded as the first device that appeared and functioned like the modern computer. Aside from using different parts, another major difference between a mechanical and an electronic computer is that the mechanical one cannot run processes without human interaction, while the electronic computer can run processes automatically. This computer was used mostly during the 1940s in World War II, but it had some continued use afterwards.
As with most computers, the mechanical computer has many varied operations and uses. Perhaps the most famous is as a calculator and stock ticker, both of which have functions that can be calculated quicker by a machine than by a human. This computer also has been used for navigation of ships, missiles and torpedoes. Hobbyists sometimes make this computer, either for fun or functional uses.