Back in 2008 the word cartocacoethes was first used on this blog to describe “a mania, uncontrollable urge, compulsion or itch to see maps everywhere.”
Counter cartocacoethes can be applied in the world of espionage allowing spies to sneak intelligence out of hostile territories – making maps that don’t look like maps.
Stained-glass windows, butterfiles, leaves, moth heads…
In making the drawings of fortified positions after ascertaining their plans, it was the work of the spy so to disguise them that their true character would not be recognized in the event of his capture by military authorities in the country where he was operating.
The plans of a fortification were first drawn in a regular manner and then disguised. In one case this was done by sketching ostensibly a stained-glass window. To the casual observer the drawing would bear no indication of its importance, but to the spy it was a carefully executed map of a military stronghold.
In another case the spy chose an ivy leaf as a pattern, the veins being drawn to represent the outline of the fortified position; the shading marking the ground sheltered from fire, and heavy spots, resembling worm-eaten holes, the positions of the large guns.
The entire article, reproduced in Popular Mechanics (July 1915) from an article in The Sketch (February 24, 1915):