Copy letter from an unknown correspondent, to Harrisons Asks Harrisons to make electros and send them with the account to Mr Walton Brown, Federated Institute of Mining Engineers, Newcastle upon Tyne, as under; [Frank] Clowes, 'Proceedings of the Royal Society', volume L, page 123, and volume LI, pages 88, 89 and 93. 11 February 1893