Preface Charles Babbage, an English mechanical engineer, mathematician and polymath, designed the world''s first programmable computer. He did this, not in our century, or even in the twentieth century, but backin the 1830s. His great friend Ada Lovelace, born Ada Byron, encouraged him and supported him emotionally in his endeavours, and her insights into his work - insights that not even Babbage had had - help posterity understand just how far ahead of its time his thinking really was. In particular, Ada saw that Babbage had in fact invented a general-purpose machine that could govern all sorts of processes, including even the composition and playing of music, whereas Babbage thought that he was only designing machines for carrying out mathematical calculations. Babbage and Ada were both geniuses and their talents existed in a kind of symbiosis with each other, although neither Babbage nor Ada fully understood this at the time. After first inventing a revolutionary machine he called the Difference Engine, devised to print accurate mathematical and navigational tables, Babbage, in 1834, realized that a much more general machine, which he christened the Analytical Engine, was possible. Programs (to use modern terminology) and data were to be furnished to the Analytical Engine by means of punched cards, which were already being used at the time to govern the operation of the Jacquard loom, a remarkable and inspired automatic loom for weaving complex images and patterns. The Analytical Engine''s output would be a printer, a curve plotter and a bell, and the machine would also be able to punch numbers onto cards to be read into the machine later.

The Analytical Engine was the world''s first ever general-purpose computer. Many of the great inventions that have made the modern world possible were devised in the nineteenth century rather than the twentieth. Of these, none is more important than the computer. Unfortunately, at the time, hardly anyone recognized the importance of Babbage''s computer, apart from Ada Lovelace. Charles & Ada is the first book to make maximum use of the extensive collection of material in the British Library Babbage archive in London. Anthony Hyman''s 1982 biography of Babbage, Charles Babbage: Pioneer of the Computer, uses some material from that remarkable archive but curiously omits - or perhaps overlooks - abundant personal material which reveals extensive information about Babbage''s personality and his personal feelings towards many of the events of his life, including his tragic private life and the rejection he felt at the hands of the world. Posterity can be grateful to Babbage for many reasons: one is that he had a habit of making handwritten copies of important letters he was sending or important documents. They may also have been early drafts and it often impossible to know whether an ostensible copy is that or an early draft.

By definition, someone''s archive usually only consists of letters or other documents sent to them, but because Babbage made these crucial copies, we have this additional material available. He was a brilliant writer, and while he expressed his own emotions rarely, when he did it was often with deeply moving intensity. Also, and this is no means a trivial consideration when one sees just how many of the letters he received from others are written in handwriting that is close to, if not completely, unreadable, his own handwriting is usually very legible and there are only a few instances where I have been unableto decipher crucial words. Anyone seeking to write Babbage and Ada''s story ought to be humbled by the task; indeed, if they were not it is difficult to imagine that the resulting biography could have any merit. This biography, like any other of Babbage, can only ever aspire to offer an approximate idea of what Babbage was like when he lived. Still, it is at least a consolation that - with perhaps only two exceptions, his beloved wife Georgiana, who died tragically young, in September 1827, and his close friend Ada Lovelace, who also died tragically too young - nobody who knew him when he was alive had very much idea of what to make of him either. Today, we do at least have the privilege of being able to look back on Babbage''s life in its entirety and to do our best to try to fathom what made this remarkable genius the man he was, and what he was really like. What is incontestable is that Babbage was a far more emotional and deeply feeling man than we have so far regarded him as being.

Still, if posterity doesn''t usually get him right in this respect, that''s to a large extent Babbage''s own fault. By all accounts, he wasn''t much of a communicator in private about his personal emotional state, and in public he was even less so, even by nineteenth-century standards. For example, in his 1864 autobiography Passages from the Life of a Philosopher (meaning ''scientist''), there is much excellent material about his plans and aims for the machines he called Difference Engine 1 and Difference Engine 2. There is also some first-rate material about the Analytical Engine, but even given the reticence we habitually expect to encounter in autobiographies written during the latter years of the nineteenth century, Passages contains almost no material whatsoever relating to Babbage''s personal life. Babbage does not even mention his beloved wife Georgiana by name on even one occasion, although he does refer to her indirectly: The Queen of Sardinia was the sister of the Grand Duke of Tuscany (Leopold II) from whom I had, many years before, when under severe affliction from the loss of a large portion of my family, received the most kind and gratifying attention. That ''large portion of my family'' certainly includes his wife Georgiana. As for Ada Lovelace, Babbage only mentions her once in a passage which is explored later. A major problem with the autobiography is that it has helped to give later generations the impression that Babbage was a hard and unfeeling, mathematically minded man without much in the way ofemotions.

Ada, on the other hand, is quite reasonably popularly regarded as being someone who wore her emotions on her sleeve and who was passionate about her work. At the start of his autobiography, Babbage employs a quotation from Lord Byron''s Don Juan (1824). Byron was Ada Lovelace''s father. The quotation, which is completely at odds with the reticence and indeed deliberate evasion of mentioning emotional topics in the autobiography, is: I''m a philosopher. Confound them all. Birds, beasts and men; but no, not womankind. In fact, Babbage misquotes Byron here: Byron wrote, ''Bills, beasts and men'' rather than ''Birds, beasts and men.'' Babbage, with an enormous inheritance, was not so preoccupied with money on a day-to-day basis as Byron was.

The misquotation may be due to Babbage confusing the lines in Don Juan with an extract from Byron''s poem Darkness (1816), which reads: . and kept The birds and beasts and famish''d men at bay. This misquotation suggests he was a man for whom women were a spiritually vital part of his life, yet it''s impossible to be certain what they really meant to Babbage. He was capable of very strong attachments and there is no doubt that he and Ada did indeed have a close romantic friendship which may possibly have become more physical, though there is no proof of this. Generally, there is very little evidence in the documentation that allows much to be written of Babbage''s feelings about women other than his devotion to his wife Georgiana and all his children, his terrible distress when his daughter Georgiana died, and his great fondness for Ada. The Sirens of Machinery In Greek mythology, the Sirens are dangerous temptresses, who sang charmingly and lured nearby sailors to their death on dangerous rocks. Machines can be Sirens too. Charles and Ada were fascinated not only by the possibility of what mechanisms could do, but tended to see mechanisms as the manifestation of a kind of earthly religion.

Babbage once remarked, when talking about a machine he''d seen in the industrial north, how extraordinary it was that every single time the machine operated, a particular part of its mechanism would reach up to exactly the same place as before. This might seem a commo.