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The First Computer: Charles Babbage’s Analytical Engine

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The modern computer was very much the result of the Second World War. The urgent necessity to innovate and face the challenge of Nazism produced machines which developed into our PCs and Tablets. But the first person to truly conceive of a computer, as we would now understand it, was Charles Babbage in the nineteenth century, and his device was called the Analytical Engine.

Charles Babbage

Charles Babbage was born in 1791. His father was a banker, and the young Babbage was fascinated by maths, teaching himself algebra and reading widely in continental mathematics. When he went to Cambridge to study in 1811 he discovered that his tutors were deficient in the new mathematical landscape, and he already knew more than they did. He thus founded the Analytical Society in 1812 to help transform the field of maths in Britain. He became a Royal Society member in 1816, and was a co-founder of several other societies. At one stage he was Lucasian Professor of Mathematics at Cambridge, although he resigned this to work on his engines. An inventor, he was at the forefront of British technology and he helped create Britain’s modern postal service, a cowcatcher for trains, and other tools. However, he disliked music, especially that played by musicians on the street.

The Difference Engine

Babbage was a founding member of Britain’s Royal Astronomical Society, and he soon saw opportunities for innovation in this field. Astronomers had to make lengthy, difficult and time consuming calculations which could be riddled with errors. When these tables where being used in life or death situations, such as logarithms for navigation, the errors could prove fatal. Babbage had the idea of creating an automatic device which would produce flawless tables, and in 1822 wrote to the Society’s president, Sir Humphrey Davy, with such an idea. He followed this up with a paper, on the ‘Theoretical Principles of Machinery for Calculating Tables,’ which won the first Society gold medal in 1823. Babbage had decided to try and build a ‘Difference Engine’.

Babbage approached the British government for funding, and they gave him what was one of the globe’s first government grants for technology. Babbage spent this money on hiring one of the best machinists he could find to make the parts: Joseph Clement. And there would be a lot of parts: twenty five thousand were planned. In 1830 he decided to relocate, creating a workshop that was immune to fire and an area that was free from dust on his own property. Construction ceased in 1833, when Clement refused to continue without advance payment. However, Babbage was not a politician; he lacked the ability to smooth relationships with successive governments, and instead alienated people with his impatient demeanour. By this time the government had spent £17,500, no more was coming, and Babbage had only one seventh of the calculating unit finished. Even in this reduced state, it was at the cutting edge of world technology.

However, his ambition was in no doubt and he upgraded his plans: in a world where calculations were usually carried to no more than six figures, Babbage aimed to produce over twenty, and the resulting Engine 2 would only need eight thousand parts. His Difference Engine used decimal figures (0-9) (rather than the binary ‘bits’ that Germany’s Gottfried von Leibniz preferred), set out on cogs / wheels which interlinked to build up calculations. But the Engine was designed to do more than mimic an abacus; it could operate on complex problems using a series of calculations, and could store results within itself for later use, as well as stamp the result onto a metal output. However, it could still only run one operation at once; nonetheless, it was designed way beyond any other competing device. Unfortunately for Babbage, he never finished the Difference Enginse. the government grants were haphazard, funding kept running out.

In 1854 a Swedish printer called George Scheutz used Babbage’s ideas to create a functioning machine which did produce tables of great accuracy. However, they had omitted security features and it tended to break down; consequently, the machines this failed to make an impact. London’s Science Museum contains the finished section, and in 1991 they created a Difference Engine 2 to the original design after six years of work. DE2 used around four thousand pieces, and weighed just over three tons. The matching printer took until 2000 to finish, and had as many parts again, although a slightly smaller weight of 2.5 tons. More importantly, it worked.

The Analytical Engine

Babbage was accused, in his lifetime, of being more interested in the theory and cutting edge of innovation than actually producing the tables the government were paying him to create. This wasn’t exactly unfair, because by the time the funding for the Difference Engine had evaporated, Babbage had come up with a new idea: the Analytical Engine. This was a massive step beyond the Difference Engine, because it was a general purpose device which could compute many different problems. It was to be digital, automatic, mechanical, and controlled by variable programs. In short, it would solve any calculation you wished, and it was basically going to be the first computer.

The Analytical Engine had four parts. A mill, which was the section which did the calculations, essentially the CPU; the store, were the information was kept recorded, essentially the memory; the reader, which would allow data to be entered using punched cards, essentially the keyboard, and the printer. The punch cards were going to come from the Jacquard loom, and would allow the machine a greater flexibility than anything mankind had then invented to do calculations. Babbage had grand ambitions for the device, and the store was supposed to hold a thousand fifty digit numbers. It would have a built in ability to weigh up data and process instructions out of order if necessary. It would be steam driven, made of brass and require a trained operator / driver.

Babbage was aided by Ada Countess of Lovelace, daughter of Lord Byron and one of the few women of the time who had an education in mathematics. She published the translation of an article along with her own notes which were triple in length.

The Engine was beyond what Babbage could afford and maybe what technology could then produce. The government had grown exasperated with Babbage and funding was not forthcoming. However, Babbage continued to work on the project until he died in 1871, by many accounts an embittered man who felt more public funds should be directed towards the advancement of science. It might not have been finished, but the Engine was a breakthrough in imagination, if not practicality. Babbage’s engines were forgotten, and supporters had a struggle to keep him well regarded; some sections of the press found it easier to mock. When computers were invented in the twentieth century, they did not use Babbage’s plans or ideas, and it was only in the seventies that his work was fully understood.

Today

It took over a century, but modern computers have exceeded the power of the Analytical Engine. Now experts have created a programme which replicates the abilities of the Engine, so you can try it yourself.

Difference Engine No. 2

How the Difference Engine Works

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