Hypergraphic Euphues

The ‘listening ears’ or sound mirrors at Dungeness, Kent…for spying on Jerry. Built in 1930 these lonely posts were manned by operators listening attentively for the sound of approaching enemy aircraft. An early warning system against invasion by air that would have given an extra 15 minutes to prepare, as planes could be heard up to 24 miles away.

Note: 

Jerry - World War I British Army slang for “German,” 1919, probably an alteration of ‘German,’ but also said to be from the shape of the Ger. helmet, which was like a jerry, British slang for “chamber pot” (1827), probably an abbreviation of jeroboam. Hence jerry-can “5-gallon metal container” (1943), a type first used by German troops in World War II, later adopted by the Allies. [dictionary.com]

(via landscapevsurbanism)