Charles Babbage

Charles Babbage was a British polymath who invented very advanced computing devices, which included the first programmable computing device. (His engines were all entirely digital, but completely mechanical.) His interests and work were very broad; they included, among other things, economics issues, and he effectively founded the field of operational research.

In 1821, while looking at some mathematical tables with his friend, the astronomer John Herschel, which contained numerous errors, an exasperated Babbage exclaimed "I wish to God these calculations could be done by steam!" It was to become his life's principal work.

A prototype of the first, the Difference Engine (an idea originated by Johann Helfrich von Müller in 1786) was started in the 1820's, but never finished. (The Science Museum recently built an actual Difference Engine, using a better design he created in 1847-49, but never attempted to build; it actually worked reasonably well.) His later proposed Analytical Engine (prototyping began in the 1860's) was the first programmable computing device, and a general-purpose one, but its program was fixed.

One of the inventions of which he was most proud was his 'Mechanical Notation', which was a way of providing a high-level abstraction of a complex mechanical system. Now little-known, and understood, it was a key, and constantly improved, tool for him in his work on the Engines.

In retrospect, he seems to have pioneered many later developments which were eventually independently re-invented, such as the separation between the CPU (which he called the 'mill'), and main memory (the 'store'). In later versions of the Analytical Engine, he made use of the mechanical equivalent of microprogramming.

The depth of the connection between Babbage and modern computers is unclear, and still debated. It seems fairly certain that his detailed work was not known to later workers (and was thus a dead end) - in part because much of it was not publicized in his time. (Much of the detail we now know of his Engines is because of fairly recent extensive study of his working notebooks, and engineering drawings, which were fortunately preserved.) On the other hand, not only were the basic ideas of the Analytical Engine publicized at the time (and later known to pioneers are far afield as Howard Aiken in the USA, creator of the Automatic Sequence Controlled Calculator), it seems that knowledge of his basic ideas was transmitted orally within the intellectual community at Cambridge; so Alan Turing, who definitely was so connected, likely knew of his basic concepts.

Collier and MacLachlan's book (below) sums him up well:

those who built the first complete working computers recognized immediately that Babbage had, in principle, invented the same machine, and that while he cannot be credited with the engineering detail of electronic computers, he was very much their intellectual and spiritual ancestor and a heroic pioneer of the new computer era.

Babbage's own prediction:

Half a century may probably elapse before anyone without those aids which I leave behind me will attempt so unpromising a task. If, unwarned by my example, any man shall undertake and shall succeed in really constructing an engine embodying in itself the whole of the executive department of mathematical analysis upon different principles or by simpler mechanical means, I have no fear of leaving my reputation in his charge, for he alone will be fully able to appreciate the nature of my efforts and the value of their results.

makes much the same point. Time has indeed shown the correctness of his vision; and the diligent work of numerous scholars, on the material he left behind, has restored to him the importance that is rightfully his.

Further reading

Books

• Charles Babbage, Passages from the Life of a Philosopher, Longman, Roberts & Green, London, 1864; re-printed Augustus M. Kelley, New York, 1969
• Charles Babbage, Henry Prevost Babbage (editor), Babbage's Calculating Engines: Being a Collection of Papers Relating to Them; Their History and Construction, E. and F. N. Spon, London, 1889; re-printed Tomash, Los Angeles, 1984; Cambridge University, Cambridge, 2010 - a large number of Babbage's original works, including several detailed ones on the Mechanical Notation; the Tomash re-print includes an informative new introduction by Allan Bromley
• H. W. Buxton, Memoir of the Life and Labours of the Late Charles Babbage Esq. F.R.S., MIT Press/Tomash, Cambridge/Los Angeles, 1988 - extensive contemporary biography, unfinished and un-printed at the time
• Philip and Emily Morrison, Charles Babbage and his Calculating Engines, Dover Publications, New York, 1961 - selected material from a large number of Babbage's publications, along with an extended introduction
• Richard H. Babbage, The Work of Charles Babbage; included in Proceedings of a Symposium on Large-scale Digital Calculating Machinery, Harvard University Computation Laboratory, Cambridge, 1947; the latter re-printed MIT Press/Tomash, Cambridge/Los Angeles, 1985 - in addition to other material from Babbage's writing, contains some detail on the Mechanical Notation
• Anthony Hyman, Charles Babbage: Pioneer of the Computer, Princeton University, Princeton, 1982 - detailed, lengthy biography with passing coverage of his machines
• Bruce Collier, James MacLachlan, Charles Babbage: And the Engines of Perfection, Oxford University, Oxford, 1998 - medium-length biography with good coverage of his machines
• Maboth Moseley, Irascible Genius: A Life of Charles Babbage, Inventor, Henry Regnery, Chicago, 1970
• Doron Swade, Charles Babbage and His Calculating Engines, Science Museum, London, 1991 - exhibition catalogue
• Doron Swade, The Difference Engine: Charles Babbage and the Quest to Build the First Computer, Viking, New York, 1991 - excellent history of the Science Museum's project to build an actual Difference Engine, includes biographical content and historical context of the original, and touches on the Analytic Engine

Papers

• Nicholas Metropolis, J. Worlton, A Trilogy On Errors in the History of Computing, Los Alamos National Laboratory, Los Alamos, 1972 - contains a section on how much early computer people knew of Babbage

External links

• Bruce Collier, The Little Engines that Could've: The Calculating Machines of Charles Babbage, Harvard University, Cambridge, 1970 - in addition to a good description of his machines, perhaps the best summary of his importance
• Allan G. Bromley, Difference and Analytical Engines; Chapter Two in William Aspray (editor), Computing Before Computers, Iowa State University Press, Ames, 1990 - covers Babbage as well as the Engines
• Charles Babbage - brief biography at the IEEE Computer Society
• Charles Babbage's Difference Engine - has content about Babbage himself too
• Plan 28 Blog - a group of people, led by Doron Swade, planning to build an Analytical Engine