Charles Babbage (Dec. 1791
– Oct. 1871)
Charles Babbage was born in
London Dec. 26, 1791, St. Stephan day, in London. He was son of Benjamin
Babbage. Then, he joined King Edward VI Grammar School in Totnes, South Devon,
a thriving comprehensive school that's still operative today, but his fragile
health status forced him back to private teaching for a period. Then, he
finally joined a 30-student closed number academy managed by Reverend Stephen
Freeman. The academy had a big library, where Babbage used to study mathematics
by himself, and learned to love it. He had two more personal tutors after
leaving the academy. One was a clergyman of Cambridge, and about him Babbage
said: "I fear I did not derive from it all the advantages that I might
have done.". The other one was an Oxford tutor who teached Babbage the
Classics, so that he could be accepted to Cambridge. Babbage arrived at Trinity
College, Cambridge in October 1810.
Design of computers
In Babbage's times there was a really high error rate in the
calculation of math tables, when Babbage planned to find a new method that
could be use to make it mechanically, removing the human error factor. This
idea started to tickle his brain very early, in 1812.
Three different elements influenced him in this decision: he disliked untidiness and unprecision; he was very able with logarithmical tables; he was inspired from an existing work on calculating machines produced by W. Schickard, B.Pascal, and G. Leibniz.He discussed the main principles of a calculating engine in a letter he wrote to Sir H. Davy in the early 1822.
Three different elements influenced him in this decision: he disliked untidiness and unprecision; he was very able with logarithmical tables; he was inspired from an existing work on calculating machines produced by W. Schickard, B.Pascal, and G. Leibniz.He discussed the main principles of a calculating engine in a letter he wrote to Sir H. Davy in the early 1822.
Difference engine
Babbage presented something that he called "difference
engine" to the Royal Astronomical Society on Jun 14, 1822 and in a paper
entitled "Note on the application of machinery to the computation of
astronomical and mathematical tables." It was able to calculate polynomials by using a numerical method called the
differences method.
The Society approved the idea, and the government granted him £1500 to
construct it, in 1823.
Charles Babbage converted one of the rooms in his
home to a workshop and hired Joseph Clement to oversee construction of the
engine. Every part had to be formed by hand using custom machine tools, many of
which Babbage himself designed. He took extensive tours of industry to better
understand manufacturing processes. Based on these trips and his experience
with the difference engine, Babbage published On the Economy of Machinery and
Manufacture in 1832. It was the first publication on what we would now call operations
research.
The difference engine project had come under fire during Babbage's absence. Rumours had spread that Babbage had wasted the government's money; that the machine did not work; and that it had no practical value if it did. John Herschel and the Royal Society publicly defended the engine. The government continued its support, advancing £1500 on April 29, 1829, £3000 on December 3, and £3000 on February 24, 1830. Work continued, but Babbage would have continual difficulty getting money from the treasury.
The difference engine project had come under fire during Babbage's absence. Rumours had spread that Babbage had wasted the government's money; that the machine did not work; and that it had no practical value if it did. John Herschel and the Royal Society publicly defended the engine. The government continued its support, advancing £1500 on April 29, 1829, £3000 on December 3, and £3000 on February 24, 1830. Work continued, but Babbage would have continual difficulty getting money from the treasury.
Analytical engine
While he was separated from the difference engine, Babbage
began to think about an improved calculating engine. Between 1833 and 1842 he
tried to build a machine that would be programmable to do any kind of
calculation, not just ones relating to polynomial equations. The first
breakthrough came when he redirected the machine's output to the input for
further equations. He described this as the machine "eating its own
tail". It did not take much longer for him to define the main points of
his analytical engine.
A design for this emerged by 1835. The scale of the work was truly incredible. Babbage and a handful of assistants created 500 large design drawings, 1000 sheets of mechanical notation, and 7000 sheets of scribbles. The completed mill would measure 15 feet tall and 6 feet in diameter. The 100 digit store would stretch to 25 feet long. Babbage constructed only small test parts for his new engine; a full engine was never completed. In 1842, following repeated failures to obtain funding from the First Lord of the Treasury, Babbage approached Sir Robert Peel for funding. Peel refused, and offered Babbage a knighthood instead. Babbage refused. He would continue modifying and improving the design for many years to come.
A design for this emerged by 1835. The scale of the work was truly incredible. Babbage and a handful of assistants created 500 large design drawings, 1000 sheets of mechanical notation, and 7000 sheets of scribbles. The completed mill would measure 15 feet tall and 6 feet in diameter. The 100 digit store would stretch to 25 feet long. Babbage constructed only small test parts for his new engine; a full engine was never completed. In 1842, following repeated failures to obtain funding from the First Lord of the Treasury, Babbage approached Sir Robert Peel for funding. Peel refused, and offered Babbage a knighthood instead. Babbage refused. He would continue modifying and improving the design for many years to come.
Second Difference Engine
Between October 1846 and March 1849 Babbage started
designing a second difference engine using knowledge gained from the analytical
engine. It used only about 8000 parts, three times fewer than the first. It was
a marvel of mechanical engineering.
The 24 schematics remained in the Science Museum archives until a full-size replica was built 1985-1991 to celebrate the 200th anniversary of Babbage’s birth. It measured 11 feet long, 7 feet high and 18 inches deep, and weighted 2.6 tonnes. The limits of precision were restricted to those achievable by Babbage.
The 24 schematics remained in the Science Museum archives until a full-size replica was built 1985-1991 to celebrate the 200th anniversary of Babbage’s birth. It measured 11 feet long, 7 feet high and 18 inches deep, and weighted 2.6 tonnes. The limits of precision were restricted to those achievable by Babbage.
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