Many people seem to be under the impression that bomb-dropping is about as simple as dropping a brick out of an upper-story window onto the head of a man beneath. This is not so. As a matter of fact, it is extremely difficult to drop a bomb from an airplane so that it will hit a desired target, for, owing to the speed at which the plane travels, the bomb when released does not drop to the ground vertically, but falls in a parabolic curve, something like that described by a man who jumps from a street-car when it is in motion. For this reason the bomb must be released some moments before the airplane is directly over the target, the ability of an aviator to determine the exact moment to pull his release mechanism being acquired only through long experience. Bomb-sights have recently been perfected, however, which have largely eliminated this element of chance. These sights have numerical scales mathematically calculated, so that when adjusted for height, air-speed as shown by the air-speed indicator, and calculated speed of the wind with or against the airplane, two sighting points are moved into such a position that if the bomb is dropped when the desired target comes in line with them, it will reach its objective—provided, of course, the aviator has made his calculations and set his sights correctly. All this sounds rather complicated, I know, and it _is_ complicated, but if the pilot uses the sight correctly his chances of hitting his target are enormously increased. All bombing planes are fitted with quick-release mechanisms, which hold the bombs firmly in a vertical or horizontal position, according to the type and size carried. On the smaller bombing planes, such as the De Havilland 4, the release mechanisms are placed underneath the fuselage or the lower wings, but on the large types, such as the Handley-Page, the bombs are carried inside the fuselage. By a quick jerk of a lever the pilot releases his bomb precisely as a hangman, by jerking a lever, drops the trap on which the condemned man stands. And the consequences are usually much the same in both cases. [Illustration: BOMBING PRACTICE. An illustration of how the enemy’s lines of communication can be destroyed by bombs dropped from airplanes. _Photograph by Signal Corps, U. S. A._] [Illustration: EGGS OF DEATH. Attaching dummy bombs to the rack of a bombing plane. _Photograph by Signal Corps, U. S. A._] [Illustration: PIGEONS HAVE BEEN REPEATEDLY USED WITH SUCCESS FROM BOTH AIRPLANES AND BALLOONS.] [Illustration: THE EYE IN THE SKY; AN AIRPLANE CAMERA IN OPERATION. During the offensive in the Argonne the American Photographic Sections made 100,000 aerophotographs of battle lines in four days. _Photograph by U. S. Air Service._]