Night-flying is one of the most hazardous duties of the aviator, the chief danger being in the difficulty of making a safe landing. Night-landing fields are, as a rule, well illuminated by flood-lights, but near the front this was not always advisable or safe, and, owing to the difficulty of judging the distance of the machine above the ground in the darkness, accidents were by no means uncommon. In order to minimize this danger there was developed the “wing-tip flare,” which consists of a small cylinder of magnesium material in a metallic holder, one of which is fitted under each lower wing of the plane. The flares are ignited by an electric current and are controlled by push-buttons, one for each flare, in the pilot’s cockpit. In making a night-landing, when the pilot judges the plane to be but a few feet above the ground, he presses one of the buttons. The flare instantly ignites and for about fifty seconds burns with a light of approximately 20,000 candle-power, which, reflected on the ground by the under surface of the wing, enables the pilot to judge his distance and effect his landing without trouble. The requirements of night-bombing have led to the development of a new and very interesting form of pyrotechnic known as the “airplane flare.” This flare, which weighs thirty-five pounds, is contained in a cylindrical case of sheet-iron about four feet long and five inches in diameter. The flare consists of an illuminating charge, capable of giving 32,000 candle-power for approximately ten minutes, which is attached to a silk parachute twenty feet in diameter. The cylinder is attached to the airplane by a light release mechanism similar to those used for holding bombs. On the end of the cylinder is a small pinwheel, which, revolved by the rush of air as the released cylinder hurtles downward, ignites the illuminating charge and at the same time detonates a small black-powder charge sufficient to eject the flare and its tightly rolled parachute from the case. The parachute immediately opens and the burning flare descends very slowly, illuminating a large area of territory underneath almost as brightly as though it were day. These flares were used particularly for night-bombing raids, the pilots thus being enabled to illuminate the objectives so that they could accurately drop their bombs. On several occasions, when raiding airplanes were met by heavy fire from the enemy’s antiaircraft batteries, it was found that the light from these flares was so dazzling as to make it impossible for the gunners to take accurate aim. So wide is the radius illuminated by these flares, and so intense their light, that it has been found possible by their aid to obtain aero photographs of excellent detail even on the darkest nights. I can personally vouch for the amazing brilliancy of these flares, for I saw one dropped by the Germans during one of their air-raids on Paris in the summer of 1918. It apparently landed on the Pont Alexandre III or in