Augusta Ada Byron (1815-1852) was the only legitimate child of the poet Lord Byron. In 1812, Byron—by then known as “mad, bad, and dangerous to know”—met Anne Isabella (“Annabella”) Millbanke. Annabella had been raised unconventionally for the time, being trained in mathematics by the former Cambridge tutor William Frend. Calling her his “Princess of Parallelograms,” Byron courted Annabella, who finally agreed to marry him in January 1815. By the time their child (always known as “Ada”) was born in December, the marriage had broken down, and Byron left England, never to return.
Ada’s mother insisted that her daughter study mathematics, as she had done; Annabella thought it would be protection against the wild, impulsive nature inherited from Byron. From the age of four, Ada studied from dawn until dusk; if she refused to do her lessons, Ada was placed in a closet.
When she was about seventeen, Ada met the famous mathematician and inventor Charles Babbage, and was immediately enamored of his calculating machine, the Difference Engine, which he was then displaying at Saturday evening soirees held in Babbage’s house in Dorset Street. An acquaintance later recalled that
“While other visitors gazed at the working of this beautiful instrument with the sort of expression, and I dare say the sort of feeling, that some savages are said to have shown on first seeing a looking-glass or seeing a gun—if, indeed, they had as strong an idea of its marvellousness—Miss Byron, young as she was, understood its working, and saw the great beauty of the invention.”
In July 1835, Ada married William, Lord King, who was elevated to the Earl of Lovelace at Queen Victoria’s coronation in 1838 (at which point Ada became known as the Countess of Lovelace). In 1839, Lovelace desired to return to her mathematical studies; she approached Babbage and asked him to suggest a tutor for her, perhaps hoping that he would take on the job himself (he would not). Soon, Lovelace was studying with the mathematician Augustus De Morgan. Today De Morgan is know as one of the founders of symbolic logic, and the one who formalized rules known as “De Morgan’s Laws” which are widely used in computer programming: negating an AND results in an OR and vice versa [that is, not (A and B) = (not A) or (not B) and not (A or B) = (not A) and (not B)].
After Lovelace had resumed her mathematical studies, she decided to help her old friend Babbage publicize his newest invention, the Analytical Engine—the first prototype of a fully general computer. In 1842, she finally realized how to do that; the Italian engineer Luigi Menabrea had published an article about Babbage’s computer in a Swiss scientific journal. It was suggested to Lovelace by Charles Wheatstone (inventor of the electric telegraph, among other devices) that she translate the article for publication in an English journal. When Babbage saw the translation, he suggested she add her own notes explaining and describing the Analytical Engine.
Over the next months, Babbage and Lovelace corresponded frequently and Babbage was often a guest at the Lovelace’s country estate. In her letters, Lovelace is at times coquettish, at other demanding, at some points lecturing the machine’s inventor about its properties and abilities. Babbage for the most part acquiesces in this treatment from his young friend, calling her “my dear and much admired Interpretress.” She refers to herself as Babbage’s “Fairy for ever.”
Lovelace added seven “Translator’s Notes,” which together ran three times the length of Menabrea’s paper. She accomplished what Babbage himself never did: introducing English readers to the workings and importance of the Analytical Engine. She also suggested to Babbage that he write a method for calculating the Bernoulli numbers with the engine—the first of what we would today call a computer program.
More importantly, Lovelace recognized that the machine was capable to manipulating symbols of all kinds, not only numbers. This recognition can be said to mark the shift from understanding computing machines as calculators to seeing them as truly modern computers. Lovelace wrote, “The engine can arrange and combine its numerical quantities exactly as if they were letters or any other general symbols.”
Babbage never publicly expressed the workings of his Analytical Engine in that way. It was Lovelace’s vision of a computer, rather than Babbage’s, that was formalized by Alan Turing in the 1930s: the notion of a computer as a general-purpose symbol manipulator rather than a number cruncher.
Sadly, neither Lovelace nor Babbage ever saw the building of the Analytical Engine. A group is now trying to raise the money to build the machine from Babbage’s plans. For more information, see here.