HOW SPIES ARE OUTWITTED.

Pelorus Guardian and Miners' Advocate., Volume 30, Issue 23, 22 March 1918, Page 2

HOW SPIES ARE OUTWITTED.

Every foreign Office in Europe acts on the theory that an army of spies is constantly on the alert to steal its secrets, and infinite precautions are taken to baffle their efforts. Very shortly after the first use of blotting paper it was discovered that it was quite possible to cause a blotting pad to give up jealously guarded secrets by simply holding it in front of a mirror. Long after all, the commercial world had forgotten the existence of such a thing., the British Foreign Office used a sand-shaker to dry its important written documents. Then specially manufactured ink blottingpaper was used, but this was not found to be spy-proof, and a return to the sand-shaker was contemplated, when someone suggested the simple expedient of a small absorbent roller. These rollers have since been used for drying diplomatic dacuments. When such a roller has been run up and down a document once or twice, the cleverest spy in the world is at liberty to try his hand at deciphering the impressions.