BABBAGE (CHARLES)

Metal storage wheel from Babbage's 1864 plan for the Analytical Engine

Footnotes

'SPECIMEN OF ONE OF THE WHEELS OF THE CALCULATING MACHINE': A PROTOTYPE STORAGE WHEEL FROM BABBAGE'S UNBUILT ANALYTICAL ENGINE.

This piece has been identified by Tim Robinson and Doron Swade, who are part of a current project to build a working Analytical Engine, as a prototype storage wheel proposed in 1864 for Babbage's Analytical Engine, the name given to Babbage's designs for the first general-purpose programmable computer. Charles Babbage (1791-1871) is often described as the father of computing, and it was his work on the various iterations of the Analytical Engine that earned him that sobriquet: '...Unique precursors of the modern computer... one of the great intellectual achievements in the history of mankind...' (Anthony Hyman, Charles Babbage, Pioneer of the Computer, 1982, p.1). Although it never came to physical fruition, the Analytical Engine was a machine ahead of its time and features key elements seen in the modern computer. In addition, not only does our unassuming cog demonstrate Babbage's ongoing experimentation with his calculating machine, it also has added significance in terms of the manufacturing process used to create it, which is arguably as important as its function.

The Analytical Engine was a more ambitious proposition than his earlier Difference Engine, which was a calculating machine with a finite capability. Work on the Analytical Engine began in 1834 and he continued improving and innovating until his death in 1871. Babbage conceived a machine that could perform any mathematical function. It was programmed by a series of punched cards, similar to those used for moving the threads on the Jacquard weaving loom, and involved hardware on a massive scale, the concept thus marking 'the progression from the mechanized arithmetic of calculation to fully-fledged general-purpose computation' (computerhistory.org).

As Doron Swade and Tim Robinson comment in relation to our wheel: 'Charles Babbage spent some 50 years of his life designing and attempting to build vast calculating engines. Despite independent wealth (his father was a banker) and the social privileges of a distinguished gentleman of science, he failed to build any of his engines in their entirety. He left an extensive technical archive of design drawings, many of which are elaborate and detailed. However, the physical relics of his efforts are less substantial in consisting of partial assemblies, experimental trial pieces, and miscellaneous loose parts. The major holdings of Babbage's design drawings, physical artefacts and assemblies are in the Science Museum's collections but there is little original material in private hands, and it is very rare for an original Babbage artefact to come to auction.

The toothed wheel is part of the store (memory) as drawn in the late period of Babbage's designs for the Analytical Engine, the earliest known description of a general-purpose digital computer that has most of the essential logical features of the modern computer. The wheel is depicted in a design drawing dated 8 January 1864 (Science Museum ref: BAB/P/181), which correlates with the date on the envelope in which it was discovered. The wheels are arranged in a stack (or column or axis) and each wheel can rotate by 9 teeth. A modest stack of loose wheels of this kind is held in the Science Museum collections. There are no known other examples of the wheel outside those holdings.

The manufacture of the wheel is consistent with it being die-stamped from flat plate. Babbage's Engines called for large numbers of near identical parts and Babbage experimented with manufacturing techniques with inherent repeatability to reduce cost and for speed of manufacture. One such technique was pressure die-casting using molten metal which Babbage pioneered in the 1860s for this purpose. The manufacture of this wheel is, however, consistent with cold stamping from thin plate. The wheel belongs to a period of experimentation and exploration, and variations of such store wheels, with the same function, appear in the drawings'.

Babbage notably enjoyed a wide circle of friends in the scientific world including Herschel and Darwin, and his famous 'Saturday soirees' of the 1830's had been frequented by the social and literary elite of his day. As Babbage was working on this concept for some years, it is therefore highly conceivable that he would have presented such a piece to a visitor or admirer who showed an interest in his ongoing work. After his death, his son Henry Prevost Babbage (1824-1918) collated his father's papers and assembled a handful of demonstration pieces from the Difference Engine which he presented to various prestigious universities, including Harvard. One of these pieces, assembled in 1879, was sold at Christie's in 1995 and is now in the Power House Museum in Sydney. As mentioned previously, the Science Museum holds various experimental components including paper cut outs of gearwheels, punched cards, twenty 'scribbling books' and some 500 drawings, but it appears that no identifiable component from the Analytical Engine has come to auction until now.

Provenance: Discovered in a disbound album possibly related to the Wedgwood family, to which Babbage's wife Georgina Whitmore was connected.

We are grateful to Doron Swade and Tim Robinson, leading experts on Babbage and his work, for their help in the preparation of this catalogue entry.