The Livens projector was deadly in its effect, since it could throw suddenly and in great quantity gas bombs, or drums, into the enemy's ranks. It is notable that although the British used this device with great success throughout much of the latter period of the war, and though the French and Americans also adopted it and used it freely, the Germans were never able to discover what the device was that threw such havoc into their ranks, nor were they ever able to produce anything that was similar to it. The Livens projector remained a deep secret until the close of hostilities, and the Government offices in Washington, where the design was adapted to American manufacture, and the American plants producing the parts, were always closely guarded against enemy espionage. Without going into details of the construction of the Livens projector it may be said that it was usually fired by electricity in sets of 25 or multiples thereof. The drums, which were cylindrical shell about 24 inches long and 8 inches in diameter, were ejected from long steel tubes, or barrels, buried in the ground resting against pressed-steel base plates. At the throwing of an electric switch a veritable rain of these big shell, as many as 2,500 of them sometimes, with their lethal contents, would come hurtling down upon the enemy. The Livens projectors could throw their gas drums nearly a mile. The projector was entirely a new type of munition for our manufacturers to handle. The Trench Warfare Section of the Ordnance Department took up the matter late in 1917 and by May, 1918, had designed the weapon for home manufacture. Early in June the contracts were allotted for barrels and gas drums, or shell. The production of barrels was exclusively in the hands of the National Tube Co., of Pittsburgh, Pa., and the Harrisburg Pipe & Pipe-Bending Co., of Harrisburg, Pa. These companies reached the production stage in August, 1918, and completed about 63,000 barrels before the armistice was signed. Their respective plants reached a daily production rate of approximately 600 barrels per day. Somewhat later in the spring of 1918 the contracts for base plates, on which the barrels rest when ready for firing, muzzle covers, and for various other accessories were closed. Over 100,000 base plates were produced by the Gier Pressed Steel Co., of Lansing, Mich., and the American Pulley Co., of Philadelphia, Pa. The Perkins-Campbell Co., of Philadelphia, built the muzzle covers, 66,180 of them. Cartridge cases were manufactured by Art Metal (Inc.), of Newark, N. J., and the Russakov Can Co., of Chicago, the former producing 288,838 and the latter 47,511. [Illustration: EIGHT-INCH LIVENS PROJECTOR, MARK II, WITH POWDER CHARGE AND SHELL. Vertical cross section as laid in the ground ready for firing at 45° elevation.] [Illustration: EFFECTS OF LIVENS PROJECTOR SHELL.]