Autograph Letter Signed ‘C.Babbage’, to Sir Benjamin Hawes, sending “the other Notes”, and hoping to make use of Lord Rosse’s assistance [in the promotion of the Analytical Engine] before Rosse returns to Ireland. 1 page, about 4 x 5 inches, in fine condition, with the integral blank leaf. 3 May 1852. Charles Babbage (1791-1871), mathematician and computer pioneer. William Parsons, third earl of Rosse (1800–1867), astronomer, President of the Royal Society. “I know Lord Rosse is anxious to get back to Ireland as soon as his duties admit and as this may be a short session, I am very desirous of availing myself of his assistance.” The reference is to Babbage’s attempts to interest Government in his analytical engine, conceived in the 1830s and worked on until Babbage’s death. In 1852 the Earl of Rosse, having seen Babbage’s new drawings for the engine, persuaded Babbage to resubmit a case to the Government for aid in the construction of difference engine No. 2. Rosse conveyed his plan, together with a letter from Babbage, to Lord Derby on 8 June 1852. Derby passed the letter to Disraeli, his Chancellor of the Exchequer, who turned the project down on the grounds of its excessive expense, and the likelihood of success being “problematical”. Babbage made no further communications to the Government on this subject.