nition stores, and the like, from observation and
possible destruction by enemy aviators. This work is done in the main
by a corps specially recruited for the purpose from the artists and
scene painters of France. It is considered prudent, for example, to
conceal the location of a certain "ammunition dump," as the British
term the vast accumulations of shells, cartridges, and other supplies
which are piled up at the railheads awaiting transportation to the
front by motor-lorry. Over the great mound of shells and
cartridge-boxes is spread an enormous piece of canvas, often larger by
far than the "big top" of a four-ring circus. Then the scene painters
get to work with their paints and brushes and transform that expanse
of canvas into what, when viewed from the sky, appears to be, let us
say, a group of innocent farm-buildings. The next day, perhaps, a
German airman, circling high overhead, peers earthward through his
glasses and descries, far beneath him, a cluster of red
rectangles--the tiled roofs of cottages or stables, he supposes; a
patch of green--evidently a bit of lawn; a square of gray--the
cobble-paved barnyard--and pays it no further attention. How can he
know that what he takes to be a farmstead is but a piece of painted
canvas concealing a small mountain of potential death?

At a certain very important point on the French front there long
stood, in an exposed and commanding position, a large and solitary
tree, or rather the trunk of a tree, for it had been shorn of its
branches by shell-fire. A landmark in that flat and devastated region,
every detail of this gaunt sentinel had long since become familiar to
the keen eyed observers in the German trenches, a few hundred yards
away. Were a man to climb to its top--and live--he would be able to
command a comprehensive view of the surrounding terrain. The German
sharpshooters saw to it, however, that no one climbed it. But one day
the resourceful French took the measurements of that tree and
photographed it. These measurements and photographs were sent to
Paris. A few weeks later there arrived at the French front by railway
an imitation tree, made of steel, which was an exact duplicate in
every respect, even to the splintered branches and the bark, of the
original. Under cover of darkness the real tree was cut down and the
fake tree erected in its place, so that, when daylight came, there was
no change in the landscape to arouse the Germans' suspicions. The lone