Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to T. L. Ibbs Esquire; The University of Edgbaston, Birmingham Informs Mr. T. L. Ibbs that his paper, 'Some experiments in thermal diffusion', is due to appear in the August number of 'Proceedings'. Asks him whether he would be willing to cover the £7.2.8. charge of the engraver which was made because the illustrations were sent in in a form unsuitable for reproduction. 21 July 1921