Charles Babbage manuscript material : 2 items

"· To Lady Byron : 1 autograph letter signed : 5 Feb 1840 : (B'ANA 0082) : discussing his research on earthquakes."
"· To Martin Archer Shee, portrait painter and writer : 1 autograph letter signed : 5 Jun 1843 : (SHEE 0113a) : 1 page (single sheet) : from Dorsett : begins, "My brother-in-law, Sir Edward Ryan, late chief justice at Calcutta wishes to make some enquiries respecting a portrait ..." Mounted in the Martin Archer Shee Autograph Album. Shelved with bound manuscript volumes under "Shee.""