Charles Babbage (1791-1871)

Charles Babbage was born in Teignmouth, Devonshire on 26 December 1791, son of a wealthy London banker.

Charles Babbage

http://www-history.mcs.st-andrews.ac.uk/history/PictDisplay/Babbage.html [Accessed 23rd October 2004]

Babbage was frustrated at the many errors he found while examining calculations for the Royal Astronomical Society, so much so that he declared “I wish to God these calculations had been performed by steam!”   Inspired by his own words, in 1823, he began trying to automate the calculating process.

His first steam driven calculating machine, the Difference Engine, was never realised, due to a number of financial and other problems.

This portion of the engine, assembled by Joseph Clement in 1832, is the first known automatic calculator. It represents about one seventh of the calculating mechanism of the full size engine which was not completed. The portion shown has nearly 2,000 individual parts.

http://www.sciencemuseum.org.uk/on-line/babbage/page3.asp [Accessed 23rd October 2004]

However, not to be put off, in 1833, Babbage began work on his next machine, the Analytical Engine.  He worked closely with his assistant Augusta Ada King, Countess of Lovelace and daughter of the poet Lord Byron.  Again, like the Difference Engine, this machine was not built in Babbage’s lifetime, due to the complexity and cost of its 50,000 components, which required precision engineering.

Augusta Ada, Countess of Lovelace – First female computer programmer!

http://www.agnesscott.edu/lriddle/women/love.htm [Accessed 23rd October 2004]

The detailed plans drawn up by Babbage described the machines five logical components: store, mill, control, input and output.  In Babbage’s own words the store, which could hold a thousand numbers of up to 50 decimal digits in length, would contain “all the variables to be operated upon, as well as all those quantities which had arisen from the results of other operations”.  The mill was the place “into which the quantities about to be operated upon are always brought”.

Portion of the mill of the Analytical Engine with printing mechanism, under construction at the time of Babbage’s death.

http://www.sciencemuseum.org.uk/on-line/babbage/page5.asp [Accessed 23rd October 2004]

The control unit was based on a device used in Jacquard looms, and controlled by punched cards.  Each card contained an instruction, such as “Transfer data from mill to store”, along with information as to where in the mill the piece of data was to be retrieved from, and where in the store it was to be stored.

Each operation of which the machine was capable (add, subtract, multiply or divide) was also stored on a punched card.  Together these cards formed a simple set of instructions, or computer program: “Every set of cards once made will at any time reproduce the calculations for which it was first arranged”.

This was therefore the first machine for which the processing was directed by an external program.  Output was also via punched cards.

Lady Lovelace created the instruction routines that would have been fed into the computer, making her the first female computer programmer.

The Analytical Engine was finally built in 1906 by Henry Babbage, the son of Charles.  It is now housed in the Science museum in London.

The Analytical Engine weaves Algebraical patterns just as the Jacquard loom weaves flowers and leaves.

(Augusta Ada, Countess of Lovelace, on Babbage’s analytical engine)  

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References

The Open University (2003) M150 Data, computing and information, Unit 6 ‘The structure of hardware and software’, Milton Keynes, The Open University.

 http://www-history.mcs.st-andrews.ac.uk/history/PictDisplay/Babbage.html [Accessed 23rd October 2004]

 http://www.sciencemuseum.org.uk/on-line/babbage/page3.asp [Accessed 23rd October 2004]

 http://www.agnesscott.edu/lriddle/women/love.htm [Accessed 23rd October 2004]

 http://www.sciencemuseum.org.uk/on-line/babbage/page3.asp [Accessed 23rd October 2004]

 http://www.bbc.co.uk/history/historic_figures/babbage_charles.shtml [Accessed 23rd October 2004]