"Sappers are gallant men of whom little is told. To them the enemy is everywhere, in strands of wire and in fields of corn. The sapper must look around him with the utmost diligence. He is like a prospector, but it is enemy mines and not gold mines that he seeks. He makes only one mistake in a lifetime. The sapper has to notice things that other men do not. Why is the grass crushed? What is that small mound? He should have a third eye and a sixth sense. The war has entered a world of rivers. These, too are the sapper's problems" (Royal Engineers Training Memorandum, May 1944, Crown Copyright)