Then and there the brothers resolved on an experiment. They made themselves a small fire of some light fuel in a little tin tray or chafing-dish, and over the smoke of it they held a large paper-bag. And to their delight they saw the bag fill out and make a feeble attempt to rise. They were surely on the eve of some great invention; and yet, try as they would, their experiment would not quite succeed, because the smoke in the bag always became too cool before there was enough in it to raise it from the table. But presently, while they were thus engaged, a neighbour of theirs, a widow lady, alarmed by seeing smoke issuing from their window, entered the room, and after watching their fruitless efforts for some while, suggested that they should fasten the tray on to the bottom of the bag. This was done, with the happy result that the bag immediately rose up to the ceiling; and in this humble fashion the first of all balloons sailed aloft. That night of 1782, therefore, marks the first great step ever made towards the conquest of the sky. But to better understand the history of “Aeronautics”--a word that means “the sailing of the air”--we must go back far beyond the days of the Montgolfier brothers. For in all times and in all ages men have wanted to fly. David wished for the wings of a dove to fly away and be at rest, and since his time, and before it, how many have not longed to take flight and sail away in the boundless, glorious realms above, to explore the fleecy clouds, and to float free in the blue vault of heaven. And since birds achieve this feat by means of wings, man’s first idea was to provide himself with wings also. But here he was at once doomed to disappointment. It is very certain that by his own natural strength alone a man will never propel himself through the air with wings like a bird, because he is made quite differently. A bird’s body is very light compared with its size. The largest birds in existence weigh under thirty pounds. A man’s body, on the contrary, is very heavy and solid. The muscles that work a bird’s wing are wonderfully powerful and strong, far stronger in proportion than the muscles of a man’s arm. To sustain his great weight in the air, a man of eleven stone would require a pair of wings nearly twenty feet in span. But the possession of such mighty wings alone is not enough. He must also possess bodily strength to keep them in sufficient motion to prevent him from falling, and for this he would require at least the strength of a horse.