A few successful experiments in balloon navigation by the aid of small engines of different forms have been made since 1855. Some believe that Count Zeppelin, an officer of the German army has solved the great problem, especially since the ascent of his ship made on July 2, 1900, at Lake Constance. It has been asserted that no vessel has yet been made to successfully fly unless made on the balloon principle, and Count Zeppelin’s boat is on that principle. According to the description of Eugen Wolf, an aeronaut who took part in the ascent referred to and who published an account of the same in the November number of _McClure’s_, 1900, it is not composed of one balloon, but of a row of them, and these are not exposed when inflated to every breeze that blows, but enclosed and combined in an enormous cylindrical shell, 420 feet in length, about 38 feet in diameter, with a volume of 14,780 cubic yards and with ends pointed like a cigar. This shell is a framework made up of aluminium trellis work, and divided into seventeen compartments, each having its own gas bag. The frame is further strengthened and the balloons stayed by a network of aluminium wire, and the entire frame covered with a soft ramie fibre. Over this is placed a water-tight covering of pegamoid, and the lower part covered with light silk. An air space of two feet is left between the cover and the balloons. Beneath the balloons extends a walking bridge 226 feet long, and from this bridge is suspended two aluminium cars, at front and rear of the centre, adapted to hold all the operative machinery and the operator and other passengers. The balloons, provided with proper valves, served to lift the structure; large four-winged screws, one on each side of the ship, their shafts mounted on a light framework extending from the body of the ship, and driven backward and forward by two light benzine engines, one on each car, constituted the propelling force. Dirigibility (steering) was provided for by an apparatus consisting of a double pair of rudders, one pair forward and one aft, reaching out like great fins, and controlled by light metal cords from the cars. A ballast of water was carried in a compartment under each car. To give the ship an upward or a downward movement the plane on which the ship rests was provided with a weight adapted to slip back and forth on a cable underneath the balloon shell. When the weight was far aft the tip of the ship was upward and the movement was upward, when at the forward end the movement was downward, and when at the centre the ship was poised and travelled in a horizontal plane. The trip was made over the lake on a quiet evening. A distance of three and three-quarter miles, at a height of 1300 feet, was made in seventeen minutes. Evolutions from a straight course were accomplished. The ship was lowered to the lake, on which it settled easily and rode smoothly.