Car of the “Liberté”
Movable rudders may be either hand or motor-operated. The double vertical steering rudder of the Ville de Paris had an area of 150 square feet. The horizontally pivoted rudders for vertical direction had an area of 130 square feet.
Arrangement and Accessories
The motor in the Ville de Paris was at the front of the car, the operator behind it. This car had the excessive weight of nearly 700 pounds. The Patrie employed a non-combustible shield over the motor, for the protection of the envelope: its steering wheel was in front and the motor about in the middle of the car. The gasoline tank was under the car, compressed air being used to force the fuel up to the motor, which discharged its exhaust downward at the rear through a spark arrester. Motors have battery and magneto ignition and decompression cocks, and are often carried on a spring-supported chassis. The interesting Parseval propeller has four cloth blades which hang limp when not revolving. When the motor is running, these blades, which are weighted with lead at the proper points, assume the desired form.
Balloons usually carry guide ropes at head and stern, the aggregate weight of which may easily exceed a hundred pounds. In descending, the bow rope is first made fast, and the airship then stands with its head to the wind, to be hauled in by the stern rope. For the large French military balloons, this requires a force of about thirty men. The Zeppelin descends in water, being lowered until the cars float, when it is docked like a ship (see page [84]). Landing skids are sometimes used, as with aeroplanes.
The balloon must have escape valves in the main envelope and ballonets. In addition it has a “rip-strip” at the bottom by which a large cut can be made and the gas quickly vented for the purpose of an emergency descent. Common equipment includes a siren, megaphone, anchor pins, fire extinguisher, acetylene search light, telephotographic apparatus, registering and indicating gages and other instruments, anemometer, possibly carrier pigeons; besides fuel, oil and water for the motor, and the necessary supplies for the crew. The glycerine floated compass of Moisant must now also be included if we are to contemplate genuine navigation without constant recourse to landmarks.
Amateur Dirigibles
The French Zodiac types of “aerial runabout” displace 700 cubic meters, carrying one passenger with coal gas or two passengers with a mixture of coal gas and hydrogen. The motor is four-cylinder, sixteen horse-power, water-cooled. The stern screw, of seven feet diameter, makes 600 turns per minute, giving an independent speed of nineteen miles per hour. The machine can remain aloft three hours with 165 pounds of supplies. It costs $5000. Hydrogen costs not far from a cent per cubic foot (twenty cents per cubic meter) so that the question of gas leakage may be at least as important as the tire question with automobiles.
The Zodiac No. 2
May be deflated and easily transported