2 SEPTEMBER 1916, Page 15

THE USE OF THE MOON IN NIGHT MAP WORK.

[TO THE EDITOR OP THE " SPROTATOR.1

Sin,—May I venture to point out to the critic of " military books " in your issue of August 19th that the use of the moon in night map work has been known to soldiers for some time ? The first account of it that I saw was in that excellent French cavalry patrol book, L'Instruction Pratique des Cadres de la Cavalerie, by the Commandant P. S., a book which appeared several years before the war. I expect I was not the only one to make use of the principle during the first part of the war ; and I have certainly explained it to many in my lectures at Tidworth, incidentally introducing it into my field sketch and message book, which has been published by Hugh Rees for some months.—I am,