A German secret service agent, after World War I, wrote a book revealing some innocent sources of military information that he had made use of in Great Britain.
From parish papers, school magazines, county journals, German intelligence culled many a tidbit telling about war factories, ports of embarkation, regiments at the front.
Last week Britain, fearing invasion, belatedly issued a warning to all head masters and editors of 36,000 religious periodicals (total circulation: 30,000,000 ), against military indiscretions. Said Britain's censor: "Don't advertise the fact that your church hall is being occupied by troops. Don't say that the path leading to the churchyard...