The super-Zeppelin contains approximately 1,000,000 cubic feet of gas and has a capacity of ten tons useful load. Of this load, about four tons can be composed of bombs or other munitions, the remainder being needed for fuel, machinery, and the crew, as well as ballast and provisions. The gross weight of a fully equipped and loaded super-Zeppelin is thirty tons, or roughly, 60,000 pounds. The envelope, which heretofore has been painted gray with liquid aluminum paint, now is impregnated thoroughly with finely divided metal, by means of the Schoop metal-coating process, which is heralded as one of the most far-reaching improvements in aerial navigation. By its means the airship envelope is made absolutely impervious to atmospheric influences. For its protection against antiaircraft fire the new super-Zeppelins carry apparatus in each gondola, producing artificial clouds of such size and intensity as to envelop and shroud completely the entire airship, rendering it absolutely invisible from below. While this cloud expands and gradually grows thinner, the airship rises rapidly in a vertical direction, speeding away while under protection of the self-made clouds. The motors of the latest Zeppelins weigh only 595 pounds each, although developing 240 horsepower, which means that one horsepower is developed for every three and three-quarter pounds of metal used. They are fitted with twin pumps, double jet carburetors, and are usually operated on mixtures consisting of one part benzol with one part alcohol. CHAPTER LIV AEROPLANE IMPROVEMENTS--GIANT MACHINES--TECHNICAL DEVELOPMENTS The experience gathered in the first eighteen months of the war by the aviators of the hostile armies has done more for the development of aeroplanes than many years of peaceful improvements could possibly have accomplished. The ever increasing size, power and stability of the heavier-than-air machine is plainly shown in the latest types of battle planes, in which a spread of wings exceeding seventy-five feet is no longer a novelty. True, the heralded approach of the gigantic German battle triplanes did not take place in the second year of the Great War, although it is an incontrovertible fact that such machines have been built and are being used for some purpose. But none of them took part in the fighting on the western front, nor has one of them been seen on the Russian battle lines. There is reason to believe, however, that these planes are used in naval reconnoitering, and their great size permits of the carrying of large supplies of fuel, giving them a great cruising radius. Reports from steamers plying the Baltic state that gigantic aeroplanes have been sighted high up in the air by captains and officers on Swedish and Danish ships, seemingly maintaining a careful patrol of that sea against possible Russian and British naval exploits.