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The Little Engines that Could've:
The Calculating Machines of Charles Babbage

A thesis presented
Bruce Collier

The Department of History of Science
in partial fulfillment of the requirements
for the degree of
Doctor of Philosophy
in the subject of
History of Science

Harvard University
Cambridge, Massachusetts

August, 1970
Copyright reserved by the author.


Charles Babbage's invention of the computer is something like the weather. Everyone working with computers for the last two decades has been talking about it, but nothing has been done. Every historical introduction to a computer text contains a section on Babbage, often extensive; but they are all based on the quite scanty information about the Analytical Engine published during the nineteenth century. The immense amount of manuscript material concerning Babbage extant in England has remained essentially untouched.

The one hoped for exception was Maboth Moseley's Irascible Genius (London, 1964). a full length biography of Babbage. Moseley consulted the Babbage correspondence at the British Museum and the unpublished biography of Babbage written by his friend Harry Wilmot Buxton; yet despite the fact that Moseley was the editor of a computer journal, she did not examine Babbage's notebooks and drawings, now in the Science Museum in South Kensington, and her book contains virtually nothing of interest on the Analytical Engine. On the whole, Irascible Genius is a good deal less interesting than Babbage's own volume of memoirs, Passages from the Life of a Philosopher (London, 1864), and it is no more balanced, and not very much more accurate.

Unfortunately, the publication of Buxton's biography would not solve the problem, for it is basically an unorganized collection of extensive extracts from some of Babbage's books, papers, and letters; and while many of these are quite interesting, they are badly in need of more coherent treatment, and there are many gaps in their coverage.

Consequently, the student of Babbage's work must return directly to the original sources. The manuscript material is in three primary collections, on which this study is based. Twenty volumes of Babbage's correspondence are deposited in the British Museum; a similar quantity of technical material is held by the Science Museum in South Kensington; and the Museum of the History of Science at Oxford University has Buxton's manuscript biography, and, more important, the Babbage papers upon which it was based.

Although Babbage's life and accomplishments encompassed far more that was important than the invention of his two calculating machines, the Difference and Analytical Engines, it is on them that new research has most been needed; consequently, the present study is limited to material relevant to them. Babbage's early mathematical work, his role in founding or reforming several important scientific societies, and his many other activities will scarcely be touched upon. But the first chapter, by way of introduction, will provide a brief sketch of Babbage's life, as it is the context into which the calculating machines must be fitted. Likewise, this study will not deal with the development of calculating machines before or after Babbage. His work was completely out of the mainstream of invention and construction which led from the primitive desk calculators of the seventeenth century to their widespread commercial success by the beginning of the twentieth century, and later to what we know as computers; Babbage was neither influenced by what had gone before nor influential upon what followed him.

The invention, development, attempted construction, and eventual abandonment of the first Difference Engine will be considered in the second chapter. The third chapter deals with the invention of the Analytical Engine and its period of primary development, from 1834 to 1847. The fourth chapter deals with three later concerns of Babbage: a project to interest the government in what he called his Difference Engine No. 2; support for the Scheutz Difference Engine, a simplified version of his own earlier machine; and his resumption of work on the Analytical Engine late in life, with the intention of attempting its construction. The final chapter will provide some observations on the general character of Babbage's work on the Analytical Engine. My own interest in Babbage was first aroused through a research project on the history of calculating machines and computers directed by Professor I.B. Cohen and Professor Owen Gingerich on behalf of the International Business Machines company for the purpose of developing an IBM museum on computers and their history; this project still continues. IBM has also provided generous financial and logistical support for my own work. A trip to England to study the manuscripts was supported by a grant from the National Science Foundation. Assistance and access to the sources has been provided by the staffs of the Manuscripts Division of the British Museum, the Museum of the History of Science at Oxford University, and especially the Science Museum in South Kensington, London, where Dr. H.B. Calvert has long had a special interest in Babbage. Professor Gingerich has read this thesis and made valuable suggestions, as has Kenneth Manning.

To all these and other individuals and institutions who have helped me in ways large and small, I express my gratitude.

Note on Sources and Quotations

The following abbreviations are used in the notes for sources frequently cited. Further information will be found in the Bibliography.

B.M. The twenty volumes of Babbage correspondence in the British Museum manuscript collections.
S.Kens. The Babbage manuscripts held by the Science Museum in South Kensington, London.
S.B. The volumes called Scribbling Books, part of the South Kensington collection.
G.S.B. The Great Scribbling Book at South Kensington.
Buxton The collection of Babbage manuscripts, together with a manuscript biography of Babbage by H. Wilmot Buxton, deposited in the Museum of the History of Science at Oxford University.
B.C.E. Babbage's Calculating Engines, edited by Henry P. Babbage, London 1889; a volume reprinting the important published material concerning Babbage's calculating machines, begun by Charles Babbage and completed and published after his death by his son Henry P. Babbage.
P.L.Y. Passages from the Life of a Philosopher, by Charles Babbage, London, 1864; a volume of memoirs.

Many of the quotations given in this thesis are from manuscript sources, often from rough notes or drafts. For the sake of increased intelligibility, punctuation has been altered to a certain extent (principally by the addition of commas), and spelling has been standardized; capitalization and italics have not been altered. Quotations from published sources are of course left unchanged.


Note on Sources and Quotationsvii
CHAPTER ONE - Introduction1
CHAPTER TWO - The Difference Engine12
CHAPTER THREE- The Analytical Engine through 1846106
CHAPTER FOUR - Babbage and Calculating Machines after 1846207
CHAPTER FIVE - Conclusion271
Appendix - Operation of the Difference Engine281

Preface   Chapter 1   Chapter 2   Chapter 3   Chapter 4   Chapter 5