CHARLES BABBAGE, AUTOGRAPH LETTER SIGNED, TO MRS ROBINSON, 25 AUGUST 1862

complaining of exhaustion ahead of a visit to her ("...the excitement of the Exhibition has done much to weaken me..."), but explaining that he is determined to complete a book that will be his revenge on critics of his Calculating Engine, 2 pages, 8vo, Dorset Street, London, 25 August 1862, lacking integral blank, adhesive remains to margin "...I have however a debt to pay to those who have used all the small power and wit they possess to destroy the Analytical Engine. I mean honestly to repay it, even with compound interest and if I should not live to publish it: my little book will, though a post-obit, be a full acquittance of my debt..."

bought from Pickering & Chatto, London, 1987

Tomash & Williams B7

This letter was written in the aftermath of the International Exhibition of 1862, at which an early Difference Engine was exhibited. The book in which Babbage planned to have his revenge on his detractors was Passages from the Life of a Philosopher, published in 1864. This rambling work, which famously included a chapter deploring street musicians, attacked Disraeli and other politicians who had failed to support his project. Babbage tartly observed that his Difference Engine could have been used to "calculate the millions the ex-Chancellor of the Exchequer squandered", and observed that Disraeli's mathematical abilities were surpassed by any junior clerk in the Exchequer.