<P> The tide - predicting machine invented by Sir William Thomson in 1872 was of great utility to navigation in shallow waters . It used a system of pulleys and wires to automatically calculate predicted tide levels for a set period at a particular location . </P> <P> The differential analyser, a mechanical analog computer designed to solve differential equations by integration, used wheel - and - disc mechanisms to perform the integration . In 1876 Lord Kelvin had already discussed the possible construction of such calculators, but he had been stymied by the limited output torque of the ball - and - disk integrators . In a differential analyzer, the output of one integrator drove the input of the next integrator, or a graphing output . The torque amplifier was the advance that allowed these machines to work . Starting in the 1920s, Vannevar Bush and others developed mechanical differential analyzers . </P> <P> Charles Babbage, an English mechanical engineer and polymath, originated the concept of a programmable computer . Considered the "father of the computer", he conceptualized and invented the first mechanical computer in the early 19th century . After working on his revolutionary difference engine, designed to aid in navigational calculations, in 1833 he realized that a much more general design, an Analytical Engine, was possible . The input of programs and data was to be provided to the machine via punched cards, a method being used at the time to direct mechanical looms such as the Jacquard loom . For output, the machine would have a printer, a curve plotter and a bell . The machine would also be able to punch numbers onto cards to be read in later . The Engine incorporated an arithmetic logic unit, control flow in the form of conditional branching and loops, and integrated memory, making it the first design for a general - purpose computer that could be described in modern terms as Turing - complete . </P> <P> The machine was about a century ahead of its time . All the parts for his machine had to be made by hand--this was a major problem for a device with thousands of parts . Eventually, the project was dissolved with the decision of the British Government to cease funding . Babbage's failure to complete the analytical engine can be chiefly attributed to difficulties not only of politics and financing, but also to his desire to develop an increasingly sophisticated computer and to move ahead faster than anyone else could follow . Nevertheless, his son, Henry Babbage, completed a simplified version of the analytical engine's computing unit (the mill) in 1888 . He gave a successful demonstration of its use in computing tables in 1906 . </P>

When was the first computer invented in the world