Unpublished paper, 'The magnetic behaviour of iron at very high temperatures' by N W McLachlan The object of McLachlan's investigation is 'to extend the range of frequency [of alternating magnetisation on iron] to 10^6 periods per second utilising a Poulsen arc generator capable of developing about 0.5kW of high frequency power' using silicon iron and pure iron plates of different thicknesses. Subject: Physics / Magnetism Received 17 November 1915. Not read. Communicated by Sir Oliver Lodge. 1915