BALLOON CONTROLLED BY WINDLASS ON A MOTOR TRUCK.
WINDLASS FOR CAQUOT BALLOON MADE BY JAMES CUNNINGHAM & SONS.
When a balloon of the Caquot type is fully inflated, the diaphragm rests upon the underbody of the gas envelope, and there is no air in the balloonette. Then, as the balloon begins to ascend, at the higher levels the surrounding air pressure is reduced and the gas in the balloon expands. This expansion would normally burst the envelope when the balloon is at a high altitude, except for a safety valve which pops at the danger point and relieves the pressure. Also, when the balloon is anchored it gradually loses gas, since no fabric can be made entirely gas-tight. A flabby balloon in a gale of wind is dangerous to the men in the basket. This flabbiness might be expected to increase, too, as the balloon was hauled down into the heavier air pressures.
It was to overcome this flabbiness that the interior balloonette was first invented, but the new location not only accomplished this end but increased the stability, lessened the tension on the cable and allowed an almost horizontal position of the balloon itself. As the balloon rises the wind blows into the balloonette through a simple scoop placed under the nose of the balloon. This forces up the diaphragm and compensates for any loss of gas from the envelope above. If the day is calm and no air is driven into the balloonette, there is no danger from a flabby balloon anyhow, and hence no need for the air chamber. The thing is automatic.
The Caquot was equipped with lobes of rubberized fabric to act as rudders. These lobes, which were spaced equidistantly around the circumference of the rear third of the balloon, filled with wind when wind was blowing and there was need of rudders. In calm weather the lobes, particularly the two upper ones, hung loosely, resembling elephant ears. On account of this characteristic the Caquots were nicknamed "elephants" by the soldiers.
The Caquot maintained its stability without tailcups, and its construction caused it to ride nearly horizontally and directly above its mooring, regardless of winds. In this position it put much less strain on the anchoring cable than the old-fashioned sausage. This balloon has been operated successfully in winds as high as 70 miles an hour, so that apparently no gale could keep it on the ground.
When we went into the war both our Army and Navy were practically without observation balloons, and we knew little about their construction, although we had been watching the developments in Europe. One local National Guard organization had taken to the Mexican border a locally designed captive balloon, the gift of the Goodyear Tire & Rubber Co., of Akron, Ohio.