Copy letter from Robert William Frederick Harrison, to John C Dobbie, Messrs A Dobbie & Son, Admiralty Buidlings, 45 Clyde Place, Glasgow The papers by Messrs [Arthur William] Rucker and [Thomas Edward] Thorpe to which Dobbie refers are: 'A Magnetic Survey of the British Isles for the Epoch Jan. 1, 186', Philosophical Transactions of the Royal Society A, volume 181, 1890; and 'A Magnetic Survey, &c, Jan. 1, 1891', Philosophical Transactions of the Royal Society A, volume 188, 1896. The papers may be obtained from Messrs Dulau & Company, 37 Soho Square, W. 8 March 1897