Suspension.—The suspension is practically the same as that of the Patrie. A steel and aluminum frame is attached to the lower part of the gas bag, and the car is suspended on this by steel cables. The objection to this system is even more apparent in the Gross than in the Patrie. A marked dip along the upper meridian of the gas bag shows plainly the deformation.
The Car.—The car is boat-shaped like that of the Patrie. It is suspended thirteen feet below the gas bag.
Motor.—The motor is a 20- to 24-horse-power, 4-cylinder Daimler-Mercedes.
Propellers.—There are two propellers 8³/₁₀ foot in diameter, each having two blades. They are placed one on each side, but well up under the gas bag near the center of resistance. The transmission is by belt. The propellers make 800 r. p. m.
Stability.—The same system, with planes, is used in the Gross as in the Patrie, but it is not nearly so well developed. At the rear of the rigid frame, attached to the gas bag, are two fixed horizontal planes, one on each side. A fixed vertical plane runs down from between these horizontal planes, and is terminated at the rear by the rudder. A fixed horizontal plane is attached on the rear of the bags as in the Patrie. The method of attachment is the same, but the plane is put on before inflation in the Gross air ship, afterwards in the Patrie. The stability of the Gross air ship in a vertical plane is reported to be very good, but it is said to veer considerably in attempting to steer a straight course.
The many points of resemblance between this dirigible and the Lebaudy type are worthy of notice. The suspension or means of maintaining stability, and the disposition for driving are in general the same. As first built, the Gross had a volume of 14,128 cubic feet less than at present, and there was no horizontal plane at the rear of the gas bag. Its maximum speed is probably fifteen miles per hour. As a result of his experiments of 1907, Major Von Gross has this year produced a perfected air ship, built on the same lines as his first, but with greatly increased volume and dimensions. The latest one has a volume of 176,000 cubic feet, is driven by two 75-horse-power Daimler motors, and has a speed of 27 miles per hour.
On September 11th of this year, the Gross air ship left Berlin at 10.25 p.m., carrying four passengers, and returned the next day at 11.30 a.m., having covered 176 miles in the period of a little over 13 hours. This is the longest trip, both in point of time and distance, ever made by any air ship returning to the starting point.
The Parseval
The Parseval air ship is owned and controlled by the Society for the Study of Motor Balloons. This organization, composed of capitalists, was formed practically at the command of the emperor, who is very much interested in aërial navigation. The society has a capital of 1,000,000 marks, owns the Parseval patents and is ready to construct air ships of the Von Parseval type. The present air ship was constructed by the Riedinger firm at Augsburg, and is operated from the balloon house of this society at Tegel, adjoining the military balloon house.
The gas bag is similar in construction to that of the Drachen balloon, used by the army for captive work. Volume, 113,000 cubic feet; length, 190 feet; maximum diameter, 30½ feet. It is cylindrical in shape, rounded at the front and pointed at the rear. The material was furnished by the Continental Tire Company. It is diagonal-thread, weighing about 11³/₁₀ ounces per square yard and having a strength of about 940 pounds per running foot. Its inner surface is covered with a layer of rubber.