The use of ballast is in getting rid of it. When the aëronaut desires to descend he pulls the line I have before described, letting the gas out of the valve at the top, when the balloon immediately comes down. Perhaps unfavourable weather, with a strong wind, may have arisen, and he suddenly sees beneath him a village, or a barn, or perhaps he has been borne out to sea. In any of these cases almost certain death would be the result of a sudden descent. So he throws some ballast out of the car, which immediately lightens it, and the balloon rises up again and carries him over the danger to some place where the descent may be made in safety. If all the ballast be injudiciously or prematurely expended, there is danger indeed in descending; and I know of one instance, at least, in which a daring but unskilful aëronaut was killed, who, in all human probability, would have been now living if he had had with him but one more bag of ballast. So, you see, I do not exaggerate when I say that ballast is sometimes worth much more than its weight in gold.
To return to our ascent. Having taken on board the extra ballast, ‘All hands off!’ is again called out aloud; again we ascend into the air, the band strikes up, the guns are fired, the aëronaut, his hand upon the liberating iron, salutes the public, the rope is detached, and we are off!
And now I will leave my passenger gazing over the side of the car, lost in amazement at the grandeur of the scene beneath him, as the horizon, rising with our ascent, discloses to view an expanse of country of which he could have had no previous conception; for I have work to do. First, I look at the aneroid barometer and find that we have arrived at an altitude of about three thousand feet, which is the height usually attained in an ordinary ascent. The gas has been coming out of the neck very freely, and the balloon is consequently beginning to descend. As we do not intend to land just yet, however, it is necessary to check the descent by parting with a little ballast, which is thrown out over the edge of the car, and has the appearance of smoke as it passes into space.
Now we are about the same weight as the atmosphere with which we are travelling. Although there was only a slight breeze on the surface of the earth, the upper current is considerably stronger, and we are going along with the clouds at a speed of a little less than a mile a minute. Yet, though travelling at this rate, we appear to be in a dead calm, and if a feather be dropped from the car it will sink slowly in a perpendicular line underneath us. When a balloon has left the earth there is no perceptible motion in it whatever. We seem to be stationary, while the fields have the appearance of rushing quickly along beneath us. We are really, as it were, part and parcel of the air, and as the current moves so we drift with it, like a cork on a running stream; and if it were possible to put you blindfold into the car of a balloon, you might be taken up into the clouds and brought down again without your being any the wiser—indeed, without your knowing anything at all about the journey.
This I have been telling you while we have been sailing along through the beautiful summer sky, taking in deep gulps of the pure air, and looking down and around upon the glorious moving panorama. But now I must leave you again to your own resources, for it is time that we should prepare for the descent, and I require to have all my wits about me. The grapnel, which is hooked on to the edge of the car, is lowered down by the rope, which is 100 feet in length, and firmly fastened to the hoop. Now we must exercise judgment and caution in selecting a proper place on which to make our descent by looking along the earth in the direction in which we are travelling. We must not come down among the crops, or we shall have the farmer after us for damages. The trees are particularly dangerous, as we have seen. So are the telegraph wires, for even if they should not destroy us, it would go hard with us in the Law Courts if we were to damage them. An aëronaut must thus have his eyes wide open, and be able to see some miles in front of him; and he must try to make for some open park or pasture land, which he can distinguish from land on which crops are growing by the cattle grazing. So the valve is opened a little, with the immediate effect of causing the balloon to descend to from 1000 to 500 feet above the earth.
Now we pass rapidly over the country until we arrive over the selected spot, when, giving the valve another stout pull, the balloon obeys and drops. Perhaps, on a closer inspection, the place we have chosen is not so favourable as it appeared at a distance; then, of course, we have to part with a bag of ballast, and ascend again until we reach a more suitable alighting ground. The grapnel takes hold at last, and on a calm day the balloon may be brought down as lightly as a feather by the regulating of the ballast; but when there is a strong current of air the grapnel will sometimes trail, which causes the balloon to jerk unpleasantly, but with good management there is no danger.
Having thus taken you up, and brought you safely down again, I will redeem the promise I make in the title by showing you
How to make a Model Balloon,
which, simple as it may seem, is in reality a very intricate operation, and you will find, as you follow me, that there is a great deal to be learned. I do not fancy you will think it at all dull work, however; on the contrary, while it is instructive and scientific, it will afford you many hours’ agreeable and innocent amusement. You have been taught how to make yachts, and have been very delighted, I have no doubt, when your first attempt at shipbuilding has proved successful, and you have seen your ship float upon the water and carry sail; but I do not think there are many readers who have had the opportunity of learning how to make a balloon which will actually hold gas and ascend into the air. Perhaps you will find this latter part of my treatise rather technical, yet I hope you will give it your attention, for I am about to endeavour to let you know more about this subject than has ever been written upon it before; and though I do not expect, or wish, to make you all professional aëronauts, I do certainly desire to awaken in your minds an interest in ballooning—a science which is daily becoming of more recognised importance.