120 ANNUAL KEPORI SMITHSONIAN INSTITUTION, 1908. 



sewed directly on the gas bag. The metal frame, or platform, is 

 attached to this net by means of toggles, so that it can be quickly 

 removed in dismounting the airship for transportation. The frame 

 can also be taken apart. Twenty-eight steel cables about 0.2 inch 

 in diameter run from the frame down to the car, and are arranged in 

 triangles. Due to the impossibility of deforming a triangle, rigidity 

 is maintained between the car and gas bag. 



The objection to the " short " suspension of the Patrie is the defor- 

 mation of the gas bag. A distinct curve can be seen in the middle. 



Gar. — The car is made of nickel steel tubes (12 per cent nickel). 

 This metal gives the greatest strength for minimum weight. The 

 car is boat-shaped, about 16 feet long, about 5 feet wide, and 2^ feet 

 high. About 11 feet separate the car from the gas bag. To prevent 

 any chance of the fire from the engine communicating with the hydro- 

 gen, the steel framework under the gas bag is covered with a non- 

 combustible material. 



The pilot stands at the front of the car, the engine is in the middle, 

 the engineer at the rear. Provision is made for mounting a telepho- 

 tographic apparatus, and for a 100-candlepower acetylene searchlight. 

 A strong pyramidal structure of steel is built under the car, pointing 

 downward. In landing, the point comes to the ground first and this 

 protects the car, and especially the propellers, from being damaged. 

 The car is covered to reduce air resistance. It is so low, however, 

 that part of the equipment and most of the bodies of those inside are 

 exposed, so that the total resistance of the car is large. 



Motor. — The first Lebaudy had a 40 horsepower Daimler-Mercedes 

 benzine motor. The Patrie w^as driven by a CO to 70 horsepower, 

 4-cy Under Panhard and Levassor benzine motor, making 1,000 revo- 

 lutions per minute. 



Proijellers. — There are two steel propellers 8| feet in diameter 

 (two blades each) placed at each side of the engine, thus giving the 

 shortest and most economical transmission. To avoid any tendency 

 to twist the car, the propellers turn in opposite directions. They are 

 " high speed," making 1,000 to 1,200 revolutions per minute. 



The gasoline tank is placed under the car inside the pyramidal 

 frame. The gasoline is forced up) to the motor by air compression. 

 The exhaust is under the rear of the car, pointing down, and is covered 

 with a metal gauze to prevent flames coming out. The fan which 

 drives the air into the ballonet is run by the motor, but a dynamo is 

 also provided so that the fan can always be kept running even if the 

 motor stops. This is very essential, as the pressure must be main- 

 tained inside the gas bag so that the latter will remain rigid and keep 

 its form. There are five valves in all, part automatic and part both 

 automatic and also controlled from the car with cords. The valves in 

 the ballonet open automatically at less pressure than the gas valves, 



