The image she had selected was both just and memorable. It paved the way for a more dramatic perception. Where Babbage had set out to design a superlative producer of tables, Ada glimpsed the possibility of programming a single piece of fixed hardware (a rather substantial one, admittedly) to do any form of computation. Always conscious that the purpose of her task was to attract project support, Ada hinted at the unforeseeable uses to which the Engine might be put, had she the space and ‘were it in actual existence’. [700] In Note A, she contented herself with declaring that the Analytical Engine would be both simpler to build than its predecessor and ‘much more powerful’. [701]
Simpler, perhaps, but there was no getting around the fact that the machine Babbage hoped to create was enormous. In Note B, without dwelling upon this point, Ada described what was to be far the largest element: a storehouse designed to contain (‘at least’) two hundred columns of discs. Here, Ada transformed Menabrea’s correct, but flat image of a column of circular discs into the more vivid ‘pile of rather large draughtsmen . . . each counter having the digits from 0 to 9 inscribed on its edge at regular intervals’. [701]
While Ada’s imaginative gift for making the invisible apparent is one of the most successful aspects of her ‘Notes’, this is not primarily what has led her to be seen as a significant figure in scientific history. Throughout her seven notes, over and again, Lady Lovelace returned to the idea of the Analytical Engine’s potential to meet the challenges of a future world. In Note E (requiring a detailed use of the trigonometry that she had only recently mastered), Ada again stressed this point through reference to the Engine’s adaptability. It might be supposed, Ada wrote, that a machine which gave its results in numerical form could work only with numbers. But this, she announced in the old assertive voice of her mathematical correspondence with De Morgan, was an error.
The engine can arrange and combine its numerical qualities exactly as if they were letters or any other general symbols; and in fact it might bring out its results in algebraical notation, were provisions made accordingly. It might develope [sic] three sets of results simultaneously, viz. symbolic results (as already alluded to in Notes A. and B.); numerical results (its chief and primary object; and algebraical results in literal notation. [713]
Babbage, as Ada acknowledged in her next sentence, had actually made no plans for his Engine to do any such thing, but Babbage’s plans were never going to hold his more boldly imaginative interpreter back. As Stephen Wolfram has stated in a fine recent analysis of Ada’s ‘Notes’: ‘Babbage did not know what he had; Ada started to see glimpses and successfully described them.’
Ada Lovelace, in her personal correspondence, often made claims about her own powers that bordered on the preposterous. Where Babbage’s invention was concerned, she reined back that impulse. In Note F, she remarked that the engine could be used to determine ‘that which human brains find it difficult or impossible to work out unerringly’ [722]; in Note G, another ten-pager that has become the most famous of all Ada’s ‘Notes’, she cautioned the reader against any temptation to overrate Babbage’s invention.
To exaggerate the powers of the Analytical Engine, Ada wrote, would invite the reverse to take place. Certainly, Babbage had devised a means of improving the pace of scientific progress. Nevertheless, there must be no supposition that the inventor had created the ‘thinking machine’ that Lady Byron had loosely termed it back in 1833. ‘The Analytical Engine has no pretension whatever to originate anything,’ Ada wrote in one of her most quoted and discussed statements. Babbage agreed.
Having cut the machine (so to speak) down to size, Ada built it up again in a final and remarkable endeavour. Menabrea, indicating the Analytical Engine’s sophistication as a computer of numbers, had introduced the name of Jakob Bernoulli, the deviser, back in 1713, of a series of numbers which continue to play a basic theoretical role in surprisingly many aspects of mathematics. Working with this sequence of ugly-looking and increasingly complicated fractions, Bernoulli himself claimed to have been able to compute his first ten numbers in fifteen minutes; Ada, painstakingly drawing up what today looks like the first computer program (William Lovelace proudly inked it in before carrying it off to display to neighbours and friends), offered an example by which the Analytical Engine was shown to be capable of computing fifty Bernoulli numbers in a minute. This was a task which neither the earlier Difference Engine nor its precursors could have addressed.* It was Ada’s most striking demonstration – the chart showed informed readers how a string of instructions from punched cards would guide the machine through a progressive sequence of events – of the Analytical Engine’s potential value to any country willing to cough up the considerable funds required to build it.†
Ada visited her mother in Leicestershire at the beginning of 1843, while her husband travelled to Germany, seemingly to glean new architectural ideas for the ongoing transformation of East Horsley Place into Horsley Towers, his own magnificently idiosyncratic take on a Bavarian schloss.
In 1843, the cost of William Lovelace’s Surrey fantasia (fifteen woodland bridges, new access roads, a lake, cloisters, a chapel, a courtyard, a tower and a gigantic hall formed only a portion of the grand project) was mounting by the minute.
Lavishing money on his building projects, William remained tight-fisted with his wife. Anna Jameson, writing to the Noels in Dresden in January 1843, chattily confided that Lady Byron wished her extravagant son-in-law would augment a £300 a
