DECEIVING the sharp eyes, and the cameras, of the enemy has become so important in modern warfare that all military organizations of leading nationshave specialists constantly devising newl tricks of .concealment or striving, to “see through” the foe’s camouflage. Since the idea is to confuse or dazzle the enemy’s observers, the camouflage corps of the British nayy has been given the name of the “Dazzle Department.” In the world war the British and French protected the positions of their guns from aerial observation by erecting acres of net tents - tents of dazzle - on which were stenciled masses of color blending harmoniously with the surface of the earth. But the Germans hurdled this obstacle by perfecting color filters which made it possible to distinguish pigment colors from those of natural verdure. Organic dyes, which will defy detection by filters used by either the human eye or the camera, are said to be available today and net tents now used by the French are far superior to those of 1914. Camouflage in 1940 is a much more difficult undertaking than it was during the world war. All the European nations have made aerial surveys of areas of potential military interest. Thousands of such photographs are catalogued and filed for future reference. If new photographs show changes when compared with those on file, camouflage will be suspected immediately. Development of aerial photography has stimulated greatly the art of camouflage. Men throughout the world have been working valiantly to disprove the old saying that “the camera doesn’t lie”; Aerial photographs record the earth’s surface in masses of light and shadows. The camouflage artist aims to produce conditions that will deceive the camera. The perspective of aerial photographs is vertical. In ordinary life the eye sees objects in a nearly horizontal plane. A cultivated district is seen from the air as a checkerboard of fields divided by hedges. Conglomerate land areas, containing demolished villages, shelled areas or patchy vegetation, present highly complex patterns, offering an excellent opportunity for the light-and-shadows camouflage technique. The camouflager studies the landscape from photographs and plans his work accordingly. It is important that the perspective lines of the locality be duplicated in the camouflage. The work mt harmonize with the contours of the dxsam, otherwise the deception will be apparent readily in a photograph, as for example, in one taken when the sun is low and objects throw long shadows. A mound must be a mound, and a flat sury face must be a flat surface; otherwise their shadows will betray the deception. Plans for the detection of camouflage, by the use of stereoscopic methods have been developed. Hundreds of aerial photographs have been taken of potential battle areas. When a photograph of a section is placed on one side of the stereoscope, and,a recent photograph placed upon the other side, if the contour of the land has been. disturbed by erection of works, it will show up as an irregularity to the eyes of the investigator. Thus has the optical plaything of a past and simpler generation been converted into a device of warfare. Most familiar to the general public is the camouflage of ships. By painting irregular shapes on a ship its silhouette is blurred, thereby making accurate aim of missiles from submarines difficult. In the last European war the use of camouflage is said to have reduced materially the marksman ship of submarines. During the past ten years considerable study has been given to the development of scientific principles of ship camouflage, with the result that not only can vessels be made very blurry in form and outline, but they can, through the clever use of optical illusions of line and mass, be made to appear running a different course than they actually are. The submarine commander, thinking the ship is about to turn from its course, aims his torpedo accordingly, and frequently will miss because of the optical illusion of the ship’s movement. Zigzag steering of vessels is a deceptive stratagem which is now used extensively in the war zone. The aiming of torpedoes, as other modern military projectiles, involves highly complicated mathematics. If a ship changes its course even slightly the calculations are rendered valueless and success in hitting the vessel with a torpedo becomes largely a matter of luck. Automatic zigzag steering devices have been perfected and are now being used extensively, and are supplanting to a large extent the painting of optical illusion designs on vessels. Much camouflage, both terrestrial and naval, is made to reduce visibility. A dirty gray battleship is less easily seen than is a black, or brightly colored ship. Some camouflagers believe that if a ship is painted in splotches of many colors, carefully selected, the colors mingle at a distance in an indistinct gray that has lower visibility than a ship completely gray. Airplanes are painted, like birds, with dark upper surfaces and light under surfaces. When viewed from the earth, planes are seen against a blue background, and for that reason lighter colors lower their visibility. By the clever use of colors an airplane can be made virtually invisible at | high altitudes. When viewed from overhead by pursuit planes, aircraft are against a brown and dark-green background. Their visibility is lessened when the upper surfaces are painted with colors that blend with the.surface of the earth. Bomber planes, which usually operate at night, are painted a dull black to deaden the reflection of searchlights. Release by the German government recently of aerial photographs of London indicates how extensively aerial photography has been developed by the European powers. One of these photographs shows in great detail the storage tanks holding petroleum so vital to England in carrying on the war. Camouflage now would be of little value in respect to those oil storage tanks, for the enemy already has detailed photographs of their position. This situation illustrates that camouflage for fixed objects in the future must be planned long in advance of when it may be needed. Power plants, oil storage tanks and other vulnerable works may disappear from formed the foliage into shades of brown. But camouflage apparently was a neglected or unknown art during the eighteenth century when the British soldiers wore bright red uniforms and marched in solid formation. Not until the Boer war did British uniforms get down to a practical and utilitarian basis. Following its experience in that war Britain in 1903 adopted khaki serge for her troops. “Khaki” is an oriental word meaning dusty. The color was adoped both because it does not soil easily as do brighter colors and also because it affords a measure of concealment. The United States has standardized on uniforms ofolive drab color, it being felt that this particular shade has greater camouflage value in military operations. The German army wear uniforms of a peculiar gray shade, it being claimed that this shade has high camouflage protective value in northern climes (Germany is in the same latitude as Labrador). The French main army have uniforms of “horizon blue,” but the French colonial armies wear khaki. Finnish troops wore white garments on the snow fields during their struggle against the Russians, with satisfactory results. The outstanding classic example of camouflage is related by Homer in the Iliad. He tells how the ancient city of Troy, besieged for nearly a decade, was finally captured through the stratagem of erecting- outside the walls an immense wooden horse. The besieging Greeks let it be known that the immense horse was constructed as an offering to Minerva, a goddess who was angry with the Greeks and was aiding the beleagured Trojans. The inside of the wooden horse was filled with armed men and the other Greeks repaired to their ships as though to depart. The Trojans thought the enemy had abandoned the siege, so they dragged the horse inside the walls. That night the men in the wooden horse emerged and opened the gates of the city to their comrades who had returned. The city was set on fire and Troy was subdued.