“The temperature is very even,” remarks the captain, “and there is no danger of it rising or falling unexpectedly, at least not for an hour or more. We might as well travel with the guide-rope, and skip along close to the earth.”
He slips the line overboard and lowers it carefully to the ground.
The guide-rope, though a mere cable, about two hundred feet in length, is a very delicate accessory to a balloon, and the most important after the anchor. When in operation, one end of the rope is attached to the basket, and a quarter or a fifth of its length is allowed to drag on the surface of the earth, where it regulates automatically the air-ship’s aerostatic equilibrium.
If the balloon has a tendency to fall, an additional portion of the guide-rope drops upon the ground. Instantly the “Rolla” is relieved of that much weight, and soon resumes its former altitude.
On the other hand, should its tendency be to rise, the extra amount of rope that it hauls up with it means for the “Rolla” a few pounds more to carry, and it gradually falls back to its original position.
It has also the serious advantage of saving gas, and sand ballast as well.
“That modest young fellow you met at dinner the other night,” remarks the captain, “uses the guide-rope with great success as part of the steering-gear of his new aeronef, the ‘Santos-Dumont V.’ We all expect to hear within a few weeks that Santos-Dumont has solved the great problem of aerial navigation.”
The farmers who can not understand this new method of locomotion are all eager to tug at the guide-rope, thinking we have decided to land.
“Mais non! Laissez donc!” shouts the owner; “nous nous promenons, tout simplement.”