Due to the lack of funds, the United States Government has not been able to undertake the construction of an air ship sufficiently large and powerful to compete with those of European nations. However, specifications were sent out last January for an air ship not over 120 feet long and capable of making 20 miles per hour. Contract was awarded to Capt. Thomas S. Baldwin, who delivered an air ship last August to the Signal Corps, the description of which follows:
Gas Bag.—The gas bag is spindle shaped, 96 feet long, maximum diameter, 19 feet 6 inches, with a volume of 20,000 cubic feet. A ballonet for air is provided inside the gas bag, and has a volume of 2,800 cubic feet. The material for the gas bag is made of two layers of Japanese silk, with a layer of vulcanized rubber between.
Car.—The car is made of spruce, and is 66 feet long, 2½ feet wide and 2½ feet high.
Motor.—The motor is a 20-horse-power water-cooled Curtiss make.
Propeller.—The propeller is at the front end of the car, and is connected to the engine by a steel shaft. It is built of spruce, has a diameter of 10 feet, 8 inches, with a pitch of 11 feet, and turns at the rate of 450 r. p. m. A fixed vertical surface is provided at the rear end of the car to minimize veering, and a horizontal surface attached to the vertical rudder at the rear tends to minimize pitching. A double horizontal surface controlled by a lever and attached to the car in front of the engine, serves to control the vertical motion and also to minimize pitching.
The position of the car very near to the gas bag, is one of the features of the Government dirigible. This reduces the length and consequently the resistance of the suspension, and places the propeller thrust near the center of resistance.
The total lifting power of the air ship is 1,350 pounds of which 500 pounds are available for passengers, ballast, fuel, etc. At its official trials a speed of 19.61 miles per hour was attained over a measured course and an endurance run lasting two hours, during which seventy per cent of the maximum speed was maintained.
Dirigible No. 1, as this air ship has been named, has already served a very important purpose in initiating officers of the Signal Corps in the construction and operation of a dirigible balloon. With the experience now acquired, the United States Government is in a position to proceed with the construction and operation of an air ship worthy of comparison with any now in existence, but any efforts in this direction must await the action of Congress in providing the necessary funds.