Letter from H M [Hector Munro] Macdonald, 52 College Bounds, Aberdeen, to [Joseph] Larmor He has not heard from Larmor for some time, and asks how he spent Autumn. He describes his own holiday in the hills. He may come to the L.M.S. [London Mathematical Society] meeting that month, but owing to a shortage of students and assistants he is shorthanded. They are living in an atmosphere of rumours of spies and submarines. He wonders if it has occurred to authorities that the easiest way to detect a submarine is by aeroplane, even if it is at considerable depth, comparing the two to a solan goose and haddock. Probably some torpedo could be dropped for the purpose. Aberdeen is now a training place for the new armies. 2 November 1914