Early inventors thought they would be able to steer balloons by means of sails, like a boat, but they soon found that this was impossible. The effect of hoisting a sail at the side of a balloon was merely to swing the balloon round until the sail was in front, while meantime it continued its course unaltered. The use of a rudder and other means were also tried, but without success; nor can such methods ever hope to succeed so long as a balloon floats in the air at the same pace as the wind that carries it forward. A balloon travelling with the wind may be compared to a boat drifting idly with the tide. As long as she drifts she refuses to answer her rudder, which swings idly. But presently the boatman hoists a sail, and the wind carries the boat onwards faster than the tide, and then immediately the rudder comes into action. Or should there be no wind, he may accomplish the same thing by dragging an anchor or other weight in the water, and so slowing his boat down until it moves slower than the current; he will then again find that his boat will answer her helm. To steer his course in a balloon, therefore, the aeronaut must so arrange that he is travelling faster or slower than the wind in which he finds himself. To travel faster, he must employ some sort of engine or motor to drive his craft onwards. To travel slower, he must trail something along the ground beneath to act as a drag. Part of the equipment of every balloon is a long trail-rope, which, when the balloon is aloft, hangs some 300 feet below the car. The object of this rope is to break the force of the fall when the balloon comes down to the earth at the end of the voyage. In the greater number of cases a balloon, in its final swoop to the ground, falls the last few hundred feet with considerable, and often uncomfortable, speed. But when provided with a trail-rope, as it descends more and more of the heavy rope will lie along the ground, and so lighten the weight of the balloon, and lessen the shock of falling. If then a trail-rope were used of such length that it would sweep along the ground while the balloon was flying in the air, the effect would be to put a drag or brake on the balloon, and so render it capable of being steered to some extent with a sail; and this is what has actually been done in all attempts of the kind. But since a long rope dragging rapidly across the country is a very dangerous object, capable of doing great damage, and also liable to catch in trees and other obstacles, such experiments can only be tried with safety over the sea, or, as in the case of Andrée’s voyage, over desert or uninhabited country. The best way of steering a balloon, therefore, is to provide it with some mechanical power which shall urge it onwards at a greater speed than the wind; and when this is done, it has ceased to be a balloon in the popular sense of the word, and has become an “airship.”