Letter from Alex [Alexander] Larmor, Knock-na-Geary, Banbridge, to Joseph [Larmor] He has been there a week and will be returning to Derry where he will work on the reflection problem. He notes an experiment of Bragg's where 'the ray of platinum is incident at the reflecting angle on a thin piece of diamond' and the light examined by reflection from rock salt. The result was a difficult thing to understand. John is staying with him at present and seems better. 31 July 1915