SAPPERS its cellars into dug-outs, build huts on its lawns? If you are a soldier you will have no other architects, surveyors, electricians, or plumbers than the R.E.s. 'When the waters were dried an' the Earth did appear, ("It's all one," says the Sapper), The Lord He created the Engineer, Her Majesty's Royal Engineer, With the rank and pay of a Sapper!' The little house, set in the French countryside, where dwells the Engineer-in-Chief, the Grand Master of all the R.E.S, shelters an infinite diversity of specialists. Side by side with the Geologist, who possesses a perfect knowledge of that part of France, its strata and its resistance in various places: who even in peace-time was visiting the region in which he is interested with the foremost geologists of France, dwells the Camouflager who, tirelessly checking his own intuitions with aerial photography, has come to know from experience what is seen and what is not seen. He it is that studies a photograph and has a too dangerous camp evacuated. He it is that can differentiate between the tracks of the harmless beasts of the field and those that are vehicle-made. And it is he that puts false trenches beside the real ones, false block-houses beside real block-houses, mock guns beside guns: and patiently begins all over again until no photograph can distinguish between the true and the untrue. It is he that camouflages camouflage.