was sitting in the rooms of the Analytical Society, at Cambridge, my head
leaning forward on the table in a kind of dreamy mood, with a table of
logarithms lying before me. Another member, coming into the room and seeing me
half asleep called out, "Well, Babbage, what are you dreaming about?"
to which I replied, "I am thinking that all these tables (pointing to the
logarithms) might be calculated by machinery" (Passages from the Life of a Philosopher)
-- Charles Babbage
(Passages from the Life of a Philosopher)
“dream” became his obsession. In 1822, Babbage presented to the Analytical
Society a small model for his Difference Engine, a machine capable of
calculating mathematical tables, such as a table of logarithms,
In his paper, Babbage demonstrated exactly how his machine could calculate the
terms of a particular polynomial at the rate of about one
term every five seconds. Impressed
with his prototype, the British government awarded him a number of grants over
the next few years. Unfortunately, The Difference Engine
proved too difficult and too costly to build and Babbage’s
dream never achieved completion.
Despite his earlier disappointment, in 1835, Babbage created plans
for a much more ambitious machine, The Analytical Engine.
This machine had many of the components of a modern computer: a control
unit (punched card control), memory (the store), a processor (the mill), an
input device (cardreader), and an output device (a printer). Although The
Analytical Engine was never built, Charles Babbage's design was a precursor
for a modern computer.