http://www.powerhousemuseum.com/collection/database/ Powerhouse Museum Collection en-au 3 1 50 http://www.powerhousemuseum.com/collection/database/?irn=150269&search=96-203-1&site_id=3 96/203/1 Calculating engine, specimen piece, with instructions and engraving, 'Difference Engine No1', bronze / steel / wood / paper, designed by Charles Babbage, parts made by Joseph Clements, assembled by Henry Provost Babbage, England, 1822-1879 http://www.powerhousemuseum.com/collection/database/?irn=150269&search=96-203-1&site_id=3 http://www.powerhousemuseum.com/collection/database/?irn=150274&search=96-203-1&site_id=3 96/203/2 Letters (2), from Countess Ada Lovelace to Charles Babbage, paper, England, 1838-1847 http://www.powerhousemuseum.com/collection/database/?irn=150274&search=96-203-1&site_id=3 http://www.powerhousemuseum.com/collection/database/?irn=150277&search=96-203-1&site_id=3 96/203/3 Medal, Astronomical Society Prize, gold, maker unknown, England, 1824 http://www.powerhousemuseum.com/collection/database/?irn=150277&search=96-203-1&site_id=3