MENABREA, Luigi Federico. Sketch of the Analytical Engine invented by Charles Babbage ... with notes by the translator [Augusta Ada King, Countess of Lovelace]. Offprint from Scientific Memoirs III (1843). London: Richard and John E. Taylor, 1843.
8o. Folding table and text tables. Black morocco.
Provenance: Presentation inscription from Lady Lovelace's husband, William King, Earl of Lovelace, on the title: "C. R. Weld Esq with Ld Lovelace's compts." The recipient was Charles R. Weld (1813-69), author of A History of the Royal Society (1848), which contains the first authorized printed announcement of Ada's authorship of the above translation.
FIRST SEPARATE EDITION, extremely rare, of the most important paper in the history of digital computing before modern times. After the appearance of Menabrea's paper, the daughter of Lord Byron, Augusta Ada King, Countess of Lovelace, became interested in preparing an English translation. The resulting collaboration between Bryon's celebrity daughter and Babbage is one of the more unusual in the history of science. At Babbage's suggestion, Lady Lovelace added seven explanatory notes to her translation, which run about three times the length of the original. Because Babbage never published a detailed description of the Analytical Engine, Ada's translation of Menabrea's paper, with its lengthy explanatory notes, represents the most complete contemporary account in English of the intended design and operation of the first programmable digital computer. Her annotated translation has been called by many authorities the most important paper in the history of digital computing before modern times. Babbage considered this paper a complete summary of the mathematical aspects of the machine, proving "that the whole of the development and operations of Analysis are now capable of being executed by machinery."
As part of his contribution to the project, Babbage supplied Ada with algorithms for the solution of various problems. These he had had worked out years ago, except for one involving Bernouilli numbers, which was new. Ada illustrated these algorithms in her notes in the form of charts detailing the stepwise sequence of events as the hypothetical machine would progress through a string of instructions input from punched cards. These procedures, and the procedures published in the original edition of Menabrea's paper, were the first published examples of computer "programs."
Ada also expanded upon Babbage's general views of the Analytical Engine as a symbol-manipulating device rather than a mere processor of numbers. She brought to the project a fine sense of style that resulted in the frequently quoted analogy, "We may say most aptly that the Analytical Engine weaves algebraic patterns just as the Jacquard-loom weaves flowers and leaves." She suggested that it "might act upon other things besides number, were objects found whose mutual fundamental relations could be expressed by those of the abstract science of operations. . . . Supposing, for instance, that the fundamental relations of pitched sounds in the science of harmony and of musical composition were susceptible of such expression and adaptations, the engine might compose elaborate and scientific pieces of music of any degree of complexity or extent (p. 694) . . . Many persons who are not conversant with mathematical studies, imagine that because the business of the engine is to give its results in numerical notation, the nature of its processes must consequently be arithmetical and numerical, rather than algebraical and analytical. This is an error. The engine can arrange and combine its numerical quantities 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" (p. 713).
Much has been written concerning what mathematical abilities Ada may have possessed. She had been tutored in mathematics by Augustus De Morgan. Their genuine friendship aside, Babbage's motives for encouraging Ada's involvement in his work are not hard to discern. As Lord Byron's only legitimate daughter, Ada was an extraordinary celebrity, and as the wife of a prominent aristocrat she was in a position to act as patron to Babbage and his engines (though she never in fact did so).
Bound with this offprint of the Menabrea-Lovelace paper is the offprint of Babbage's addendum to it (see below) which details Babbage's problems in obtaining government support for the development of his engines. Besides this account of the Analytical Engine, and its prior appearance in French, the only other published description of the operation of that machine during Babbage's lifetime was the account in his autobiography. Van Sinderen 1980, no. 55. When OOC was written, OCLC and RLIN cited two copies of the offprint of Lovelace's translation (both at Harvard University). We know of three copies of the offprint, including this one, in private hands. None of the others are inscribed. From Gutenberg to the Internet 6.1; OOC 61.
[Bound with:] [BABBAGE.] Addition to the memoir of M. Menabrea on the analytical engine. Offprint from The London, Edinburgh and Dublin Philosophical Magazine and Journal of Science, 3d ser., 23 (1843).
4 pages. Babbage originally wrote this anonymously published account of his calculating engine projects and dealings with the British government as an addendum to the translation of Luigi Menabrea's article on the Analytical Engine prepared by his friend Ada King, Countess of Lovelace. Van Sinderen 1980, no. 55. OOC 62.