Babbage’s “Mona-Lisas” & his legacy in computer collecting
For a museum to become world-class and attract visitors over and over again, it needs its “Mona Lisa”. For a computer museum, this artefact needs to be a “first” machine, unique, such as the only surviving prototype or model of a recognised technological milestone (Bell, 2011). In this regard, Charles Babbage’s Difference Engine, Difference Engine №2 and Analytical Engine form the ultimate collectibles.
Charles Babbage (1791–1871) is often credited as the father of the computer. His Difference Engine is the first great automatic calculating machine designed to tabulate polynomial functions. The construction was commenced in 1822 and the work was continued during the following twenty years. The British Government contributed about £17,000 and Babbage about £6,000. At the end of that time, the construction of the engine, though nearly finished, was unfortunately abandoned owing to some misunderstanding with the Government (Horsburgh, 1914:124).
The incomplete Difference Engine was put on display to the public at the 1862 International Exhibition in South Kensington, London. Early exhibitions, starting with the Great Exhibition of 1851, at the Crystal Palace — ending with the 1876 exhibit of the ‘Special Loan Collection of Scientific Instruments’, formed the core collection of the future Science Museum of London (at the time called South Kensington Museum). Note that with the Deutsches Museum, Munich (the world’s largest museum of science and technology), the Science Museum of South Kensington formed the most complete collection of calculators at the turn of the 20th century.
In 1848 Babbage commenced the drawings of an improved difference engine, and though he subsequently completed the drawings, the improved engine was not made. The drawings of Difference Engine №2 are archived at the Science Museum since the late 19th century (Baxandall, 1926; Bromley, 1991).
Babbage began to design his Analytical Engine in 1833 and he put together a small portion of it shortly before his death in 1871. This engine was to be capable of evaluating any algebraic formula, of which a numerical solution is possible, for any given values of the variables. The formula would be communicated by perforated cards similar to those used in the Jacquard loom. The engine was planned in three sections: the “Jacquard apparatus”, the “mill”, and the “store”. Seven years after Babbage’s death, a committee was formed to estimate the expense of constructing the Analytical Engine but concluded that no reasonable estimate of its cost or strength or durability could be given. In 1906, Babbage’s son, Major-General H.P. Babbage, completed the part of the engine known as the “mill” (Horsburgh, 1914:127). This is he who presented the different parts of the Analytical Engine as well as other Charles Babbage artefacts and drawings to the Science Museum (Baxandall, 1926). Then followed two World Wars…
During the 1980s, Prof. Allan G. Bromley, famous collector of calculating and computing devices, studied Babbage’s original drawings at the Science Museum library. This work led the Science Museum to construct a working calculating section of Difference Engine №2 from 1985 to 1991, under the supervision of Doron Swade, the then Curator of Computing. It took 17 years to complete the entire device, with the printer part built in 2002. In 2008, a clone of this engine was made at the Science Museum, commissioned by Nathan Myhrvold, and shipped to the Computer History Museum (CHM), Mountain View, California. This clone remained at CHM until 2016 (it is now on display at Intellectual Ventures, Seattle, a private company co-founded by Myhrvold).
This article is divided into two parts. First, we will follow Babbage’s artefacts in the Science Museum throughout the 20th century, by tracking them in scarce collection catalogues, once owned by Bromley and now part of The Tricottet Collection, and by documenting the making of Difference Engine №2 in the 1980s-90s, using Bromley’s Science Museum correspondence archive, also held by The Tricottet Collection. Second, we will cross the Atlantic Ocean to see how the first ever museum dedicated to computers, the CHM, obtained its own “Mona Lisas”, such as large mainframes which names often end in “AC” (read further), the Cray supercomputers, or the scarce Apple I computers.
Babbage Engines at the Science Museum
This section is illustrated with collection catalogues and correspondence letters once part of the Bromley estate. To learn more about Allan George Bromley (1947–2002) the collector, read our Medium article ‘The Bromley collection of calculators’. We will focus here on his work on Babbage’s Engines at the Science Museum, his greatest legacy. Note that he was also a world leading expert on the oldest mechanical calculator, the Antikythera mechanism, yet again another “Mona Lisa”, which will be the subject of a future article.
Babbage artefacts in collection catalogues (ex. Bromley library)
The Tricottet Collection was fortunate enough to secure from the Bromley library three collection catalogues related to calculating and computing devices (Horsburgh, 1914; Baxandall, 1926; Pugh, 1974). The descriptions given below follow the collection catalogue ‘Origins of Cyberspace’ (OoC) (Hook and Norman, 2002), which has become the standard bibliographical reference on the history of computing and telecommunications (Kidwell, 2003) and which includes, among other historically important documents, a nearly complete collection of Babbage’s rarest publications on computing (Christie’s, 2005).
◀ HORSBURGH, ELLICE MARTIN, ed. Napier tercentenary celebration. Handbook of the exhibition of Napier relics and of books, instruments, & devices for facilitating calculation. Edinburgh: Royal Society of Edinburgh, 1914. Original printed wrappers.
vii, , 343, pp. 7 plates, text illustrations. 256 x 177 mm.
The Napier tercentenary celebration, marking the three hundredth anniversary of the publication of Napier’s Mirifici logarithmorum canonis descriptio (1614), was held in Edinburgh from July 24 to July 27, 1914 — just five days before the start of World War I […] A celebration of Napier’s pivotal role in the history of calculation, the exhibition featured displays of many different types of calculating machines, as well as exhibits of other aids to calculation such as mathematical tables, the abacus and slide rules, planimeters and other integrating devices, and ruled papers and nomograms […] The Handbook was published in two forms: a softcover version as above, presented to those who registered for the exhibition; and a hardcover version issued for sale under the title Modern Instruments and Methods of Calculation […]. Relatively few copies of the softcover version seem to have been distributed at the exhibition, partly because the exhibition took place in Edinburgh, but mainly because war broke out just after it began [OoC 322].
◀ BAXANDALL, DAVID. Catalogue of the collections in the Science Museum, South Kensington, with descriptive and historical notes and illustrations. Mathematics. I. Calculating machines and instruments. H. M. Stationery Office, 1926. Original green printed wrappers.
85, pp. 13 plates, 246 x 155 mm.
A well-annotated and well-illustrated historical catalogue, focusing primarily on European calculating machines and instruments from the seventeenth to the early twentieth centuries. Among the machines illustrated are two machines built by the Earl of Stanhope, and an original Morland calculator. All three of these machines were formerly owned by Charles Babbage. This remained the most useful and informative exhibition catalogue of early calculating instruments through the 1960s. An updated edition of the catalogue was issued in 1975 [OoC 222]
◀ Pugh J. (1975), Calculating Machines and Instruments, Catalogue of the collections in the Science Museum. Science Museum, revised and updated edition of Baxandall (1926), 102 pp. [OoC 222]; accompanied by a letter from J. Shore to A.G. Bromley, dated 29 May 1990, about the return of this catalogue (1-page signed printout, Powerhouse letterhead; not shown).
We learn from Horsburgh (1914) that the Science Museum only lent photographs of portions of Babbage’s Difference Engine and Analytical Engine for the Napier exhibit. A further photograph showed the “mill” of the Analytical Engine, put together by the youngest son of the inventor. We have to wait for Baxandall (1926) to learn about the extend of the Babbage collection held at the Science Museum and how the institution formed it. The Difference Engine was lent by the Board of Trade in 1862 (Baxandall, 1926:Pl. VIII; inv. 1862–89, 26592). The portion of the Analytical Engine (inv. 1878–3, S.M. 51, 65), as well as other artefacts and documents (original drawings and papers referring to Babbage’s calculating machines, experimental models, moulds) were received in 1878 and presented by Major-General H.P. Babbage in 1905. The “mill” section of the Analytical Engine, built under the supervision of H.P. Babbage (inv. 1896–58, 1911–339, S.M. 506) was received in 1896. Work was carried on intermittently from 1880 to 1896 but again, once in the Science Museum, between 1906 and 1910. A device was then added for printing the calculated results on paper, from which a zinc block could be made. An impression from such block was exhibited, as of 1926. No additional information is provided in Pugh (1975) which indicates that the collection stood still over the 1910–1975 period.
Noteworthily, Babbage owned two machines built by the Earl of Stanhope and a Morland calculator, now at the Science Museum [OoC 222]. It remains unclear if Babbage was an early collector of computing devices or if he only used those machines as study material. In his article ‘Collectorabilia Dr. Allan Bromley’, Bromley implied that Babbage was a collector when he wrote “Apart from the relative scarcity of memorabilia dating back more than a decade or so, there are certain practical difficulties involved in collecting computers from before about 1970 […] A more practical proposition for those determined to start yet another memorabilia/collecting trend is to collect parts of computers — printed circuit boards, for example, or a vital integrated circuity or transistor type. Babbage would no doubt be impressed” (Bromley, 1981)…
Life at the Science Museum & the making of Difference Engine №2
… which brings us to Bromley’s multiple visits to the Science Museum library in the 1980s and 1990s and his fascination with Babbage’s engines. Bromley’s thorough study and deciphering of Babbage’s original drawings led to the publication of ‘The Babbage Papers’ in 1991, a catalogue listing all the Babbage documents part of the Science Museum library collection. Below are unique excerpts from letters referring to this period, about his work at the museum and his life as a collector while in London.
◀ The making of Difference Engine №2 (as of 1990). (a) Letter from Doron Swade to Allan Bromley, Science Museum letterhead, typed and signed, dated 13 October 1990, regarding the final assembly of Difference Engine №2 and the publication of Bromley’s ‘Babbage Papers’: “Approximately 1,000 of the 4,000 engine parts have been delivered and the build-site (prime site on the ground floor opposite the big Mill Engine) has been prepared for assembly in public view. We are very slightly behind schedule — there were delays with one of the foundries on the framing pieces. We are also having trouble with discolouration of the figure wheels from the silver-soldering process. Ordinary category of niggles none of which are critical and none insoluble. Michael, as you know, is well plugged in and has been an absolutely invaluable source of guidance and expertise. Given inherent unknowns in the assemble it is difficult to predict how far we will have progressed when you visit so forgive me if I appear vague about exploiting your very welcome and much appreciated offers of assistance. The more advanced the assembly, the more needy we will be of your expertise and help” — Doron Swade was the Senior Curator (Computing & Control) at the Science Museum where his major project was to organise the construction of Difference Engine №2, in collaboration with Bromley; (b, not shown) Letter from Fred Lipsett to Bromley, typed and signed, dated 8 September 1991: “I have been reading with great interest articles in Science and New Scientist about the construction of Difference Engine №2 of which you seem to have been the investigator. Congratulations! According to the reports the Engine cost 295 000 pounds to build and another 200 000 to exhibit. You must be the most expensive visiting research fellow the Science Museum (or any place else) has had…” (Lipsett was a scientist and musician who had occasionally worked on the Antikythera mechanism).
◀ Robot exhibits at the Science Museum and its “sister” Victoria & Albert Museum, 1984–1990. (a) Bayley, S. and J. Woudhuysen (1984), Robots. The Conran Foundation, Boilerhouse Project, Victoria & Albert Museum, 60 pp. (with penned note “Allan G Bromley 25–4–86”) — This volume accompanied an exhibition looking at the history of automation and how it affects design. The Victoria & Albert Museum and the Science Museum were once the South Kensington Museum, back in the second half of the 19th century, before the science and art collections got split (Science Museum, n.d.); (b) Letter from Michael Wright to Allan G. Bromley, dated 6 April 1990, asking for “helpful direction” about “hosting an exhibit on Robotics or Industrial Robots or … (ill-defined) and part of the Japan Festival” (handwritten 2-page letter, Science Museum header). It reads for instance “I have been detailed to be Curator […] and in the mean time I am ‘to become expert in robotics’ […] I am beginning by reading the most recent books to be found in the Library under 61–52 beginning with those most obviously specifically on robots; I am starting gently on F.L. Schodt ‘Inside the Robot Kingdom’ and have also P. Marsh ‘The Robot Age’ and P. Coiffet & M. Chirouze ‘An Introduction to Robot Technology’. Any suggestions? […] I think I told you in Athens how shy I feel of exhibition work; you can perhaps imagine how I feel at the prospect of this one…” — Michael T. Wright (born 1948), curator of mechanical engineering at the Science Museum, was a close collaborator and friend of Allan Bromley. They worked together on the Babbage drawings but their main work together was on the understanding of the Antikythera mechanism (subject of a future article). Another interesting fax sent from Wright to Bromley in 1994 (on fax thermal paper, not shown but part of The Tricottet Collection) consists of Wright’s 9-page typed manuscript on the Stanhope Calculating Machines part of the Science Museum. Wright’s postscript reads: “I do not know if other specimens of this machine exist […] So far as I am aware, no one has published any study of these machines. It seems to me that this would be worth doing, particularly as I believe that the design provides significant precedents for some features of Babbage’s designs for calculating machines…”
◀ The Difference Engine №2 (as of 1991) & notes on collecting. Letter from Allan Bromley, handwritten aerogramme, dated 8 January 1991, contacting Sydney clockmaker Frank Percival who was helping Bromley to create a model of the Antikythera mechanism at the time. After mentioning his work with Michael Wright on this mechanism, he goes on with a review of the progress on the making of Difference Engine №2: “The Difference Engine №2 is well underway. It goes up and down like a yo-yo a bit as they partially strip for fitting. The main vertical cast iron frames have warped, despite being normalised. Fortunately it seems to have happened before the making out and fitting of subframes so all is well. Some problems with supply from one sub-contractor delaying work, but generally all seems on target for July. The engineers building are quite competent. My Babbage cross-reference list publication is all systems go. […] Have yet to contact Doron Swade re the opening, etc. in July…”. We also learn some more about Bromley’s collecting while in London: “Tramping around the markets of course. But there is very little to be had and even less at a modest price. I have bought a few small items. Mostly not really new, but improvements on existing items in my collection. As always same problems with books.” Now it is interesting to check Bromley’s calculating devices and collection labels since they are generally dated. The Tricottet Collection holds for instance a collection label from 1991 that reads: “Two slide gager’s slide rule | J. Long, 43 Eastcheap, LONDON | Light staining, otherwise good condition | £38” (see ‘The Bromley collection of calculators’).
▲ Collecting calculating devices in London in 1991. Letter from Stuart Talbot to Allan Bromley, typed and signed, dated 6 August 1991, regarding the availability of a Thomas de Colmar calculator (incl. original stamped envelope, photocopy of calculator description page and Bromley’s reply file copy): “It was great of you to give father & I a guided tour of the Babbage exhibition during your recent visit to London — the exhibition is bringing in a lot of Collectors from Europe this summer. Here are photographs & brief specification of the fine THOMAS de Colmar Calculator №899 which I am offering subject to being unsold at £2800.00, with best wishes, Stuart” to which Bromley answered: “Dear Stuart, Thank you for sending me the information about the Thomas de Colmar calculator. After some heart searching, for it is a fine and interesting calculator, I have had to face up to the realities of my current financial position…” We also learn some interesting anecdote about the Analytical Engine: “I have been doing some work since I returned on the 1871 model of the Analytical Engine. Surprisingly, it was mostly assembled, and I think the printing mechanism and the control/drive mechanism were designed by Henry Babbage after Charles’ death. So Charles never got to see a working model of any of his Analytical Engine ideas. It’s a little sad really.”
Other computer “Mona Lisas” & collectibles
The Computer (History) Museum, from Boston to Mountain View
The process of building a computer museum and the quest for “Mona Lisas” is well described in ‘Out of a Closet: The Early Years of The Computer Museum’ by Bell (2011). The Boston Computer Museum originates from a 1975 closet-size exhibit showing logic and memory elements. The curators, at the time, were inspired by the Science Museum, London, and the Deutsches Museum, Munich, which were the references in this domain from the late 19th century onward. Bell refers to their “many “first” machines, and the original plans of legendary computer pioneer Charles Babbage” (Bell, 2011: 132). The Computer Museum (TCM), at Boston, was claimed to be, in 1982, the only institution dedicated to the industry-wide preservation of information processing devices and documentation (the aforementioned museums had a wider scientific and technological scope).
Interestingly, computer pioneer Maurice Wilkes, already mentioned several times, opened The Digital Computer Museum with a talk on the programming of the Cambridge University EDSAC. The museum acquired the micro-processor from the EDSAC II from the Science Museum in the early 1980s (The Digital Computer Museum, 1982:2).
One of the main “Mona Lisas” of TCM (before it got dissolved in 1999) was the JOHNNIAC computer. It now resides at the Computer History Museum (CHM), Mountain View, California. The CHM saved the vision of TCM and most of its precious holdings by some transfer through the late 1990s (Bell, 2011:143). Of the “Mona Lisas” displayed at the CHM, we should mention Myhrvold’s Science Museum reconstruction of the Babbage Difference Engine No. 2 on loan there, as of 2011 (Bell, 2011:144). Bell goes on in listing the many interesting artefacts part of the CHM: Napier’s Bones, Pascaline replica, Enigma, ENIAC, JOHNNIAC, UNIVAC, PDP-1 with Spacewar (the first ever video-game), an Apple I, Xerox PARC’s Alto, etc., etc.. Apple I computers have now become the must-have, yet out of reach to most collectors. One for example sold for $240,000 to a private collector (Bell, 2011:145). Another specimen sold for $471,000 at Christie’s in 2019.
It seems that Allan Bromley’s 1981 recommendations to the new collector still hold today: “Apart from the relative scarcity of memorabilia dating back more than a decade or so [as of 1981], there are certain practical difficulties involved in collecting computers from before about 1970 […] A more practical proposition for those determined to start yet another memorabilia/collecting trend is to collect parts of computers — printed circuit boards, for example, or a vital integrated circuity or transistor type.” With the variety of computer models released from the 1980s to the present day, one could also, quite easily if space permits, build a systematic collection of vintage computers. As for the best way to collect rare books and ephemera related to computing, the reading of ‘Origins of Cyberspace’ becomes a priority when preparing a want-list. This book also details Norman’s collecting process, and in the same spirit, one should read ‘Out of a Closet: The Early Years of The Computer Museum’ by Bell (2011). Finally, one could watch a couple of videos featuring some private collectors, which include for instance famous MythBusters co-host Adam Savage.
As for video game collecting, this is a slightly different story that we will cover in a future article…
Baxandall D. (1926), Catalogue of the collections in the Science Museum, South Kensington, with descriptive and historical notes and illustrations. Mathematics. I. Calculating machines and instruments. H. M. Stationery Office, London, 85 pp. [copy in TC: ex. Bromley library, with penned note “Allan G. Bromley 28–3–84” and Bromley address sticker]
Bayley, S. and J. Woudhuysen (1984), Robots. The Conran Foundation, Boilerhouse Project, Victoria & Albert Museum, 60 pp. [copy in TC: ex. Bromley library, with penned note “Allan G Bromley 25–4–86”]
Bell G. (2011), Out of a Closet: The Early Years of The Computer Museum. Jones C.B., Lloyd J.L. (eds.), Dependable and Historic Computing, Lectures Notes in Computer Science, 130–146
Bromley A.G. (1981), Collectorabilia Dr. Allan Bromley. In: COMDEC magazine, Oct. 81, pp. 58–60 [copy in TC: ex. Bromley estate, with original handwritten draft article]
Bromley A.G. (1982), Charles Babbage’s Programs for the Analytical Engine. 4 pp., 1 Pl. in The Life and Work of Charles Babbage, A One Day Meeting of Four Lectures 10 December 1982, National Physical Laboratory, Teddington, Middlesex [copy in TC: ex. Bromley estate]
Bromley A.G. (1983), Inside the world’s first computers. New Scientist, 99 (1375), 781–784 [copy in TC: ex. Bromley estate]
Bromley A.G. (1991), The Babbage Papers in the Science Museum Library, a cross-reference list. Science Museum London, 294 pp. [copy in TC coll.: ex. Bromley library, penned notes “At home Allan Bromley”; accompanied by a letter from Anthony Wilson to Bromley, Science Museum letterhead, typed and signed, dated 3 April 1991, regarding final corrections and printing of the book]
Bromley A.G. (2000), Babbage’s Analytical Engine Plans 28 and 28a — The Programmer’s Interface. IEEE Annals of the History of Computing, 22 (4), [copy in TC: ex. Bromley estate]
Business Day (1993), Lab sells its supercomputer at a bargain — for $10,000. Wednesday, April 14, 1993 issue [copy in TC: ex. A. Cole, laminated and signed]
Christie’s (2005), The Origins of Cyberspace, Wed. 23 Feb. 2005, New York, 247 pp.
Hook D.H., Norman J.M. (2002), Origins of Cyberspace: A library on the history of computing, networking and telecommunications, with contributions by M. R. Williams. Published by www.historyofscience.com, Novato, California, 670 pp. [copy in TC coll.: regular limited ed. of 500 copies, bound in heavy cloth with silver stamping, inscribed to the TC, signed by both authors]
Horsburgh E.M., ed. (1914), Napier tercentenary celebration, Handbook of the exhibition of Napier relics and of books, instruments, & devices for facilitating calculation. Royal Society, Edinburgh, 343 pp. [copy in TC: soft cover ed., ex. Bromley library]
Kidwell P.A. (2003), Origins of Cyberspace: A Library on the History of Computing, Networking, and Telecommunications (review). Technology and Culture, 44 (1), 193–194.
Pugh J. (1975), Calculating Machines and Instruments, Catalogue of the collections in the Science Museum. Science Museum. Revised and updated edition of Baxandall (1926), 102 pp. [copy in TC coll.: ex. Bromley library, with penned notes “Allan G. Bromley £2-50 ”, “Allan G. Bromley 22/8/79”, Bromley Sidney Uni. 1980 stamp and Bromley address sticker, penned in-text notes, incl. 1990 letter from J. Shore, Powerhouse letterhead, to A.G. Bromley]
San Francisco Examiner (1993), This Cray has had its day, Thursday, April 15, 1993 issue [copy in TC: ex. A. Cole, laminated and signed]
Science Museum (n.d.), A Brief History of the Science Museum, available at https://www.sciencemuseum.org.uk/, 9 pp.
The Digital Computer Museum (1982), Digital Computer Museum Collections. Digital Computer Museum Report, 1/1982, 15 pp. [copy in TC: incl. Computer Museum leaflet and printout letter from the Computer Museum about joining the museum]
Wilkes M.V. (1953), Can Machines Think? Proc. I.R.E., vol. 41, no. 10, pp. 1230–1234 [copy in TC: unbound as issued, signed by Wilkes on the first leaf, ex. Wilkes 1999 no. 36; Origins of Cyberspace no. 1034; Christie’s 2005, part of lot 227]