Today in 1822, Charles Babbage read to the Royal Astronomical Society a paper entitled "Note on the application of machinery to the computation of astronomical and mathematical tables" in which he proposed the construction of the Difference Engine.
Considered to be a pre-curser of modern computers, it was designed to speed-up the production of error-free mathematical tables, just as early modern computers did. In 1991, London’s Science Museum completed the construction of the first-ever working model of the Difference Engine, under the direction of Doron Swade and Alan Bromley. Swade wrote in his 2000 book, The Difference Engine: Charles Babbage and the quest to build the first computer:
This book is a tale of two quests. The first is Charles Babbage’s quest to realise a vision—that the science of numbers could be mastered by mechanism. By simply turning the handle of his massive calculating engine Babbage planned to achieve results which up to that point in history could be achieved only by mental effort—thinking. But this was not all. Calculating engines offered a tantalizing new prospect. The “unerring certainty” of mechanism would eliminate the risk of human error to which numerical calculation was so frustratingly prone. Infallible machines would compensate for the frailties of the human mind and extend its powers…
The second quest is the twentieth-century sequel: The quest at the Science Museum to build a working Babbage engine in time for the bicentenary of Babbage’s birth.
Also today, in 1941, John Mauchly met John Atanasoff at Iowa State University. Over the next five days, Mauchly learned everything he could about what came to be known as the Atanasoff-Berry Computer (ABC) which he first heard about when Atanasoff visited Philadelphia in December 1940. The ABC was the first electronic digital computing device but was never put to actual use because both Atanasoff and Berry left Iowa in 1942 to contribute to the war effort and did not resume the work after the war.