2.1 Difference engine

He presented a model of what he called a Difference EngineFor the novel by William Gibson, see The Difference Engine A Difference engine is a mechanical special-purpose computer designed to tabulate polynomial functions. Since logarithmic and trigonometric functions can be approximated by polynomials, such a mac to the Royal Astronomical Society on June 14, 1822 in a paper entitled "Note on the application of machinery to the computation of astronomical and mathematical tables."[1] Its purpose was to tabulate polynomials using a numerical method called the differences method. The Society approved the idea, and this in turn enabled him to get a grant of £1500 by the British Government in 1823. The Royal Astronomical Society awarded him its Gold Medal in 1824.

Construction started on this machine, but it was not completed. Two things went wrong. One was that the internal friction and gearing available at the time were not good enough for the models to be completed — vibrations were a constant problem. The other was that he kept changing his mind about the design of the machine. An additional possible issue was disputes with the mechanic(s) hired to do the machining work. By 1833, £17000 had been spent with no satisfactory result.

2.2 Analytical engine

Between 1833 and 1842, Babbage tried again; this time, he tried to build a machine that would be programmable to do any kind of calculation, not just ones relating to polynomial equations. This was the Analytical Engine. The design was based on Joseph Marie Jacquard's weaving loom, which used punched cards to determine how a woven design would be carried out. Babbage adapted this design so that it would create mathematical actions instead.

The Analytical Engine had input devices based on punched cards, as per Jacquard's design, an arithmetic processor that calculated numbers, a control unit that determined that the correct task was carried out, an output mechanism and a memory where numbers could be stored whilst waiting their turn to be processed. It was this device that was the world's first computer. A concrete design for this emerged by 1835; however, in part because of the difficulties similar to those encountered with the Difference Engine, and in part because of disputes with the mechanics who were building the parts (and who held them hostage in what seem to have been a running labor dispute), the Engine was never built. 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. This was refused in turn by Babbage. Matters came to a halt at this point.

Babbage did receive noteworthy backing from one source. Ada, Lady Lovelace, became aware of Babbage's efforts and became very interested in them. She actively promoted the analytical engine, and wrote several programs in what would today be called assembly language for the analytical engine, but which were never actually executed. Ada Lovelace is therefore considered the world's first computer programmer, at least in the theoretical sense.

2.3 Computing — later years

In 1855, a Swedish father and son, Georg and Edvard Scheutz, successfully built a Difference Engine. It had been based on a 1834 design by Babbage. Babbage was amongst those who inspected it and gave a positive opinion. In 1859, the British Government purchased one of these for use in the Registrar General's Office. The purchase had no effect on the refusals to build an analytical engine.

Partly through Babbage's efforts at gearmaking for these machines, the British had superior machinery for the next few decades, and this contributed to the superiority of the British navy in the first world war.

3 Promotion of analytical calculus

Babbage is remembered for other accomplishments as well. The promotion of analytical calculus is perhaps the foremost amongst them. In 1812, Babbage helped found the Analytical Society. The aim of this society, led by student George Woodhouse , was to promote Leibnizian, or analytical, calculus over the newtonian-style calculus then in use throughout the British Isles. Sir Isaac Newton's calculus was clumsy, and was in use more for political reasons than practical. The Society included Sir John Herschel and George Peacock amongst its members.

In the years 1815– 1817 he contributed three papers on the "Calculus of Functions" to the Philosophical Transactions, and in 1816 was made a fellow of the Royal Society.

4 Other accomplishments

In 1824 Babbage won the Gold Medal of the Royal Astronomical Society "for his invention of an engine for calculating mathematical and astronomical tables". [2]

From 1828 to 1839 Babbage was Lucasian professor of mathematics at Cambridge. He contributed largely to several scientific periodicals, and was instrumental in founding the Astronomical Society in 1820 and the Statistical Society in 1834. During the later years of his life he resided in London, devoting himself to the construction of machines capable of performing arithmetical and even algebraic calculations.

Charles Babbage also achieved notable results in cryptography. He broke Vigenère's autokey cipher as well as the much weaker cipher that is called Vigenère cipher today. The autokey cipher was generally called "the undecipherable cipher", though owing to popular confusion, many thought that the weaker polyalphabetic cipher was the "undecipherable" one. Babbage's discovery was used to aid English military campaigns, and was not published until several years later; as a result credit for the development was instead given to Friedrich Kasiski, who made the same discovery some years after Babbage.

Babbage also invented the pilot (also called a cow-catcher), the metal frame attached to the front of locomotives that clears the tracks of obstacles. He only once endeavoured to enter public life, when, in 1832, he stood unsuccessfully for the borough of Finsbury.

5 References

Doron Swade. The Cogwheel Brain. BooksEnthsiast.com

6 See also

• History of computing hardware
• Ada Byron, Countess of Lovelace, described and programmed the analytical engine

7 External links

• McTutor biography of Babbage
• Science Museum's exhibit on the Difference engine
• eTexts of babbage's works, at Project Gutenberg
• Francis Baily, "On Mr. Babbage's new machine for calculating and printing mathematical and astronomical tables",

Astronomische Nachrichten, 2 (1824) 407/408

• "Address of the President of the Astronomical Society of London, on presenting the Gold Medal of the Society to Charles Baggage [sic], Esq." Astronomische Nachrichten, 3 (1825) 169/170

7.1 Obituaries

• Monthly Notices of the Royal Astronomical Society, 32 (1872) 101

Babbage's grave is in Kensal Green Cemetery London.

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