The contents are as follows. (i) Letters and estimate concerning the purchase by the government, for the use of the dockyard at Deptford, of the engine belonging to the Honourable George Villiers at Aldenham, 1811-1813 (folio 1); (ii) Reports, possibly by William Murdock, on the engines at Ale and Cakes, and Dolcoath copper mines near Redruth in Cornwall, 1782 (folio 9); (iii) Description of a Boulton and Watt engine made for Mark Bell, Battersea, undated (folio 13); (iv) Letters concerning and plans of the engine at Leader, Atlee and Langdale's distillery, Battersea, 1808, 1811 (folio 15); (v) Notes of experiments and calculations concerning the engine at Pitfirrane, 1778, 1783-1784 (folio 42); (vi) Papers connected with the legal disputes between Boulton and Watt, and Jonathan Hornblower and Edward Bull concerning patent infringements, in which John Rennie was involved as an expert witness. This material includes specifications and drawings of Hornblower's double action engine installed at the colliery at Radstock, 1781, 1784, 1787, 1792-1793, 1795, 1799 (folio 46).