Letter from G [George] Johnstone Stoney, 8 Upper Hornsey Rise, to [Joseph] Larmor In the enclosed paper [not present] Stoney has attempted to give a secure foundation for [Ernst] Abbe's mode of analysing images, and to extend it. He has tried to keep abstract considerations and mathematical symbols out of it. This was to make the paper more widely read, as a man such as himself who has spent most of his life in non-scientific work finds it hard to get a hearing. He is proud of his first fundamental theorem, which he discusses. The conditions he describes hold good for sound waves, but they do not hold under any mechanical theory of light. He thinks they must be regarded as electromagnetic waves, but he would like to see 'rigid proof' of this, and therefore he has inflicted this letter on Larmor. He thinks it interesting to apply the principle of reversal to Hertzian waves. 23 December 1896