Jacquards' Web (12 page)

talents as a toolmaker were prodigious, but he was brusque and truculent. He had a habit of sending in invoices for amounts enormously greater than what had been agreed, and digging in his heels if his customers were unwilling to pay. Babbage had frequent disputes with Clement, who, like Babbage, was grappling with a task far beyond the leading-edge technology of the time. In turn, Babbage made frequent applications to his main sponsor—the British Government—for more money.

Despite these enormous difficulties, by the spring of
1822

Babbage had assembled a small working cogwheel assembly that demonstrated the operation of the Difference Engine. He announced the completion of his model in a paper to the Royal Astronomical Society dated
2
June
1822
, and also in an open letter to Sir Humphry Davy, President of the Royal Society, dated
3
July
1822
. Babbage deliberately wrote the letter for a wide readership. In it, he reviewed the success of his working 76

The Difference Engine

model, described at great length the problems he had to over-come, and emphasized the expense involved. The letter received wide attention among the London scientific and mathematical worlds. It even came to the attention of Parliament. In due course, on
21
July
1823
the Treasury announced a grant of

£
1500
to Babbage to enable him to ‘bring his invention to perfection in the manner recommended’.

Generous as the Treasury’s initial grant was, the precise terms of the deal were never spelled out. In particular, the Treasury did not make it clear whether it expected the £
1500

to be enough to complete the machine, or what procedure to follow if it was not. As matters turned out, it soon became clear that the £
1500
was not nearly enough to allow Babbage to have any chance of completing his Difference Engine. He applied for more funds, and was granted them. Indeed, by
1834
the Government—convinced by the recommendations of influential people, and by the strength of Babbage’s own conviction that the Difference Engine would be of enormous benefit to society when completed—had advanced to him a total of £
17 470
, about £
1
million at today’s prices. This was a vast sum by any standards. To give some idea of how much money the Government had invested in the Difference Engine, the steam locomotive, John Bull, which was completed by Robert Stephen-son and his company for shipment to America in
1831
, cost

£
784 7
s.

During this period of intense hard work, Babbage suffered two personal tragedies that stayed with him for the rest of his life.

The year
1827
began with the death of his father on
27
February
1827
. Benjamin, largely a self-made man, had always considered his eldest child to be a failure. By the time of Benjamin’s death, the work on the Difference Engine did not add up to anything which the old man—who saw the world almost entirely in financial terms—would have considered an achievement. With Benjamin’s death, Charles lost the opportunity eternally to redeem himself in his father’s eyes.

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Jacquard’s Web

A worse blow was to come. Late in August, or in the first few days of September of the same year, Babbage’s wife Georgiana also died, most likely in childbirth. The precise date of Georgiana’s death is not known. The only evidence that offers an approximation of a date is a letter, dated
7
September
1827
and postmarked the same day, which Babbage received from his friend, the scientist Henry Fitton, who wrote poignantly: ‘I do not write with any hope that your friends can alleviate the suffer-ings your truly deplorable loss has caused;—for I well know the volume of what you have been deprived of—and how deeply you must feel.’

Desperate for mental distraction, Babbage went to stay with the Herschels in Slough. Babbage’s state of mind remained a serious worry to his mother, who wrote to Herschel, ‘I cannot expect the mind’s composure will make hasty advance. His love was too strong and the dear object of it too deserving.’

About a month after Georgiana’s death, Babbage left his children in the safe custody of their aunt and grandmother, and embarked on a tour of Europe. He was accompanied by one of his workmen, Richard Wright. The tour lasted more than a year, and Babbage did not return to England until late in
1828
. He had no inclination to resume living in the family home at Devonshire Street. He moved to a new house at Number One Dorset Street, which was to become such a focus of London intellectual life.

Babbage continued to toil on the Difference Engine until
1834
, dismayed by the lack of progress he had managed to make, yet too engrossed with the importance of the task he had set himself ever to consider giving in. Twelve years of failure had not caused this extraordinary man to waver from his course.

And then, one night in December
1834
, Charles Babbage had an epiphany that radically changed not only the direction of his work and life but also the shape of the history of technology.

That night he conceived an even more complex and ambitious machine than the Difference Engine, one that built on pre-industrial technology, but which left the steam age far behind.

78

The Difference Engine

Babbage had a vision not merely of a cogwheel calculator but of a cogwheel
computer
, and it haunted him until the end of his days.

This machine, the Analytical Engine, relied entirely on the principle behind Jacquard’s loom for its operation. In the entire history of human technology, it was the first calculating machine that was capable of being
programmed
.

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●
7
●

The Analytical Engine

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ❚ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 ❚ 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

3 3 3 3 3 3 3 3 3 3 3 ❚ 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3

4 4 4 4 4 4 4 ❚ 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

5 5 5 5 5 5 5 5 5 5 5 5 5 5 ❚ 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

6 6 6 6 6 6 6 6 6 6 6 6 6 ❚ 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6

7 7 ❚ ❚ 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7

8 8 8 8 8 8 8 8 8 8 ❚ 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8

9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 ❚ 9 9 9 9 9 9 9 9 9 9 9 9 9

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ❚ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

The work proceeded at speed. In less than two years he

[Charles Babbage] had sketched out many of the salient features of the modern computer. A crucial step was the adoption of a punched-card system derived from the Jacquard loom.

Anthony Hyman,
Charles Babbage
,

Pioneer of the Computer
,
1982

Charles Babbage was thrilled about the extraordinary new horizon that had opened up in his mind. He was like an explorer who glimpses a new continent, or an undiscovered ocean, from a mountaintop.

We can get a good idea of just how excited he was from a journal entry made late on the evening of Monday,
15
December
1834
by Lady Byron, the widow of the poet Lord Byron. Lady Byron, born Annabella Milbanke, had spent the evening in Babbage’s company with her nineteen-year-old daughter Ada, who was a close friend of Babbage. The distinguished self-taught lady mathematician Mary Somerville, later to found Somerville College at Oxford University, was also present.

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Jacquard’s Web

Lady Byron, a wealthy, self-opinionated woman, was not overly fond of Babbage, but she tolerated him because of her daughter’s liking for him and because of the social opportunities Babbage opened for both mother and daughter. Most of her letters that mention him do so in a disparaging way. In this particular journal entry, however, she reports on the evening with surprising neutrality, perhaps because she herself was rather caught up in his own excitement.

On this Monday evening, Babbage didn’t reveal to his guests at this stage precisely
what
it was he had discovered, nor exactly
when
he had made his breakthrough. His excitement and enthusiasm, however, suggest he may have had his great intellectual epiphany not long before.

Interestingly, he spoke about his discovery in metaphorical terms rather than seeking to explain it in precise detail. Why did he choose to use metaphors? He cannot have feared that the three women would have been incapable of understanding what he was saying—they all knew his work well anyway, and Mary Somerville numbered among the leading mathematicians in Britain.

Most likely what Babbage really feared was revealing too much of his discovery prematurely. Alternatively, perhaps he had not yet formulated his plans with any precision.

He told Annabella, Ada, and Mary that his first glimpse of his discovery had aroused in his mind a sensation that was something like ‘throwing a bridge from the known to the unknown world’. According to Lady Byron’s journal, Babbage also said that the breakthrough made him feel he was standing on a mountain peak and watching mist in a valley below start to disperse, revealing a glimpse of a river whose course he could not follow, but which he knew would be bound to leave the valley some-where.

The closest the women got to knowing exactly
what
it was that Babbage had discovered was a remark he uttered that his stroke of insight lay ‘in the highest department of mathematics’.

Writing in her journal, Annabella later noted soberly, ‘I under-82

The Analytical Engine

stand it to include means of solving equations that hitherto had been considered unsolvable.’

In fact, Babbage’s inspired idea was a plan for a completely new machine whose ingenuity, ambition, and sheer genius has deservedly gone down in history—the history of technology.

And, as things turned out, Lady Byron’s daughter Ada—Lord Byron’s only legitimate child—would play a crucial role in communicating the importance of the new machine to the world.

The genesis of the device Babbage was to call the Analytical Engine can be traced back to a second paper on the Difference Engine that Babbage read to the Royal Astronomical Society on
13
December
1822
.

In this second paper, he explained to his audience that useful as the Difference Engine was, it was always going to be handicapped by the need to
reset
the machine for each new set of calculations.

The point was that when a calculation started, the initial values that would govern it had to be entered into the Difference Engine by setting the Figure Wheels by hand. Once the Engine was properly set up, the handle could be turned to ensure that the calculation process went on automatically. In principle, the calculations would follow regularly without further intervention by whoever was operating it. But unfortunately, in some calculations, the results would start to become inaccurate as the table production progressed. The machine wasn’t to blame for this. It stemmed from the fact that the calculations were based on a mathematical formula which would not in every case be
precisely
accurate for every single desired numerical result.

Eventually, Babbage found a way to design a machine that would not feature this continual slight reduction in accuracy; a machine, moreover, which could do far more than simply calculate mathematical tables. He named this machine the Analytical Engine.

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Jacquard’s Web

Why did he call it that? This is not known for certain. Possibly it was because the machine was designed to
analyse
all kinds of practical mathematical problems and find solutions to them.

As the computer historian Martin Campbell-Kelly has pointed out, Babbage’s entire way of seeing the world was, in a sense, analytical: that is, he tended to solve problems by reducing them to their constituent elements and analysing those elements. In this he was in many respects typical of nineteenth-century men of science; the difference was that Babbage took analysis much further than anyone else, especially in the area of calculation.

Babbage pursued the notion of the Analytical Engine relent-lessly during the months that followed his evening with the three women. Unfortunately, little is known precisely about how his work progressed. Babbage never published a comprehensive account of the Analytical Engine, let alone details of when he made all his discoveries. He made an enormous number of drawings and diagrams for the machine, and completed some small working cogwheel components designed to be used in its mechanism. But modern computer scientists, who have spent months or even years examining his plans in detail, have concluded that it would probably be impossible to build a complete working Analytical Engine from the plans without considerable additional work and without making certain assumptions about his intentions: assumptions that might well be incorrect.

None of this is to belittle the almost incredible achievement of the intellect and imagination that the Analytical Engine represents. Even though a completed Analytical Engine was never built, and most likely now never will be, Babbage’s plans for the machine make clear beyond any doubt at all that the Analytical Engine would, indeed, have been nothing less than
a massive
Victorian computer, made out of cogwheels.

The machine Babbage designed would have been enormous, about the size of a small steam locomotive in his day or a large van today. It would have contained perhaps as many as
20 000
cogwheels, some mounted in vertical columns, as they were in the 84

The Analytical Engine

Difference Engine, but others used in a variety of other configu-rations. Thousands of gear-shafts, camshafts, and power transmission rods would have enabled calculations carried out in one part of the machine to be relayed to other parts. Taken together, a completed Analytical Engine would have been mind-boggling in size, concept, and in the functions it carried out.