Charles Babbage delivered a paper to the Royal Astronomical Society describing his Difference Engine, a machine designed to automatically compute and tabulate polynomial functions using thousands of precisely machined gears and levers. Though never completed in his lifetime, the design is regarded as a foundational conceptual leap toward automated computation.
Babbage had grown frustrated with the error-ridden mathematical tables used for navigation, astronomy, and engineering, all painstakingly calculated and typeset by hand. In his letter and subsequent presentation, he argued that a machine could compute these tables using the method of finite differences, mechanically grinding through repetitive arithmetic without the fatigue or carelessness of a human "computer," a term that at the time referred to a person's job title.
The British government, intrigued by the promise of error-free navigational tables for the Royal Navy, eventually funded Babbage's ambitious project with £17,000, an enormous sum. But the engineering tolerances required were at the ragged edge of what 1820s machining could achieve, and Babbage's perfectionism and constant redesigns meant the full engine was never finished under his direction.
A complete Difference Engine No. 2, built faithfully from Babbage's later plans using only the manufacturing tolerances available in his own era, was finally constructed by the London Science Museum in 1991 and worked exactly as he had promised. That vindication, arriving more than a century and a half later, confirmed Babbage's reputation as the conceptual father of the modern computer, decades before electricity entered the equation.
Key people: Charles Babbage