Collation: 8vo, pp. [iv] xxii 23–100 101 [1] 101–240 and pp. 241–244 corrections loosely inserted, without the final leaf of advertisements for Babbage’s other works found in some copies, full page diagrams on pp. 101[bis] 188 and 239 and other diagrams in the text.
Condition: 225 x 145mm.
Binding: Original pebble-grained grey-green cloth, printed paper spine label (no price), rebacked preserving the original spine and label.
Provenance: Inscribed ‘To Sir Bemjⁿ Brodie Bart from the Author’ in Babbage’s hand on the half title and Brodie’s engraved armorial bookplate on the free endpaper. Sir Benjamin Collins Brodie (1783–1862) was one of the most eminent surgeons of his day and President of the Royal Society 1858–61)
References: Van Sinderen 51; Norman 94 (without the corrections); Randall Origins of digital computers p. 107.
Price: £2500

First edition. A presentation copy with an unrecorded additional four page section.
¶ Babbage’s unofficial Bridgewater treatise, ostensibly an essay in natural theology, contains important ideas in the history of computing.
By far the most interesting and original parts of Babbage’s treatise were the mathematical arguments he used to demonstrate the existence of miracles – taking examples from his calculating engine, singularities in equations, and the application of Laplace’s theory of probabilities.
Martin Campbell-Kelly, ‘Introduction’ Works of Babbage (1989) vol. 9.
This copy has a previously unrecorded four page section (pp. 241–244) loosely inserted at the end. It contains minor corrections to chapter 10 ‘On Hume’s arguments against miracles’ and a complete re-working of note E on the probability of miracles. The new mathematics introduced here was re-used in the second edition (1838) with a fuller text. Another variant in this copy is that the printed spine label has no price, whereas the copy offered in my catalogue 9 no.6 had a price of 9s 6d printed on the label (it also had an advertisement leaf at the end). The Norman copy is also a presentation copy but it does not have pp. 241–4).