CHAPTER XVII. Air-Ships and Flying Machines

AIR-SHIPS AND FLYING MACHINES

WHEN we read of the great inventions of the past, we are apt to think that they would in any case have been invented some time or other, even though the great inventors themselves had never lived. But to tell the truth, each inventor had before him a great number of difficulties which he could only overcome by patient and persistent effort. It often happened that some attempt to solve the problem had been made before him, and had failed. Such a failure would lead men to believe that success was impossible. Somebody would try to prove that the problem could not possibly be solved, and that one might as well give it up as hopeless. It is just this kind of attitude which is most disturbing to inventors and discoverers. They are surrounded by friends who never cease to tell them that they are simply wasting their time in trying to solve a problem which cannot be solved.

Such a problem is that of flying through the air. The birds have solved it long ago, but even a few yearn ago it was taken for granted that no machine or engine could be built which would lift its own weight into the upper air. But within the last year the problem of human flight has been solved completely, and probably in a few years’ time the flying machine will be seen by nearly everybody every day.

This achievement means an entirely new development of civilisation. We are fortunate to live in the time of an invention which is more important than the steam-engine or the steam-ship, and will do more to bring people together than the telephone or the telegraph. We are doubly fortunate in being able to watch from day to day the manner in which the various difficulties of flying are overcome one by one. Instead of reading of great discoverers of far-off times, we can read about the triumphs of the great men of our own time. We can follow and admire the work of the heroes of science of to-day.

The first instrument which enabled man to rise into the air like a bird was the balloon. Nobody knows when the first balloon was sent up. But it is reported that at Pekin, the capital of China, a balloon was sent up at the coronation of the Emperor of China so long ago as the year 1306. In the year 1709, a priest of Lisbon is reported to have ascended into the air in a balloon filled with hot air, but the first authenic account we have of such an event dates from the year 1783.

Several years before that, Cavendish in England had found that hydrogen is fourteen times lighter than air, and that it therefore ascends through air. This was proved by filling a soap bubble with hydrogen instead of with air. It floated quickly up to the ceiling and then burst. This experiment set many people thinking about the possibility of getting things lifted up into the air by gas. Two of these people were brothers of the name of Montgolfier, who owned a paper factory in France. One day they made a great bag of paper and held it over the fire, thinking that the smoke from the fire would raise the bag into the air. But the paper was too heavy, and the balloon did not rise.

Most people would have been discouraged by such a failure, but the brothers Montgolfier guessed the cause of it, and proceeded to manage things better. They built another balloon in the shape of a box, with its opening downwards, and this time they employed silk instead of paper. They held it over a fire of straw and wool, thinking that such a fire developed a kind of gas which was very light, or which was repelled by the earth. They found, however, after a while, that the nature of the fire did not matter so long as it was hot enough. They found, in fact, that it was the hot air which really caused the balloon to rise, and that a flame burns upwards simply because it is lighter than air. How this should be so is quite clear from the principle of Archimedes, according to which a body loses as much in weight as the weight of the fluid it displaces.

We have seen already that the weight of the air inside an ordinary sized room is about a hundredweight. If therefore we construct a balloon of the same bulk as a room, and fill it with a gas much lighter than air, the balloon will weigh less than its ordinary weight by about a hundredweight. If the balloon together with a light gas which fills it weighs 60 lbs., it will be able to lift 52 lbs., or rather it will require 52 lbs. to keep the balloon down on the ground. By making the air inside the balloon hot, about 45 lbs. of air can be made to balance the pressure of the outside air, so that 60 or 70 lbs. may be the weight of the balloon itself. But by using hydrogen the weight of the gas can be reduced much further. For eight pounds of hydrogen exert the same pressure as a hundredweight of air, so that these eight pounds of hydrogen can lift 104 lbs.

The silk balloon constructed by the brothers Montgolfier rose up into the air, but fell down again as soon as it cooled. They therefore made a new balloon 40 feet high, constructing the envelope of packing-cloth covered with paper. The lower end was open, and under it was hung an iron cradle filled with moist straw and wool, which gave a slow fire, and helped to keep up the heat of the balloon. The new balloon rose into the air in June 1783, and soon sailed out of sight, bearing a message up to the clouds that mankind was about to enter their territory.

The news of this great success quickly reached Paris, and led to many attempts to imitate and develop the striking invention. In Paris, the work was taken up by the brothers Robert, makers of scientific instruments, and Professor Charles, a young and promising physicist. They made a balloon 12 feet in diameter and filled it with hydrogen gas. It rose into the air and sailed away before a huge crowd of people. A few days afterwards, the brothers Montgolfier brought to Paris a giant balloon 72 feet high, which also rose into the air, but was held back by ropes. A week after that they attached to the balloon a car of wickerwork, in which they put a sheep, a cock, and a duck. The balloon came to the ground somewhere out in the country, and all the three animals alighted safe and sound.

The success of these first three navigators of the air encouraged the human inventors of the balloon to venture themselves into cloudland, and in November of the same year two Frenchmen ascended in a fire-balloon and sailed over Paris across the river Seine. To show that the same could be done in a balloon filled with hydrogen, Charles and Robert made an ascent in a gas balloon a few days later. The balloon was made in lengths of red and yellow silk. It was provided with a net, to which the car was attached, with a valve for letting out the gas, with a barometer for measuring the height, and with bags of sand. The sand was taken as ballast, and was used to lessen the weight of the balloon when it was sinking too quickly.

The great hopes built upon the balloon were not fulfilled for many years. Benjamin Franklin, when he first saw a balloon, said he had seen an infant which he hoped to see grow into a giant. But for ninety years no decided improvement was made in the construction of the balloon. Bold investigators of the air were found to cross the Channel from Dover to Calais, or from London to Germany, as Green did in 1836 in a giant balloon filled with coal-gas. Some great heights were reached. In 1862 two Englishmen named Glaisher and Coxwell rose to a height of seven miles, the greatest height ever attained by people in a balloon. Their pulses rose till they gave 110 beats per minute instead of about 70 or 80 beats per minute. Their faces became purple, and finally Glaisher became unconscious. Coxwell lost the use of his hands in the extreme cold of the upper air, but he managed to pull the valve rope with his teeth, and so they both returned safely to Mother Earth.

During the Franco-German war a number of balloons were sent up from Paris when it was besieged by the Germans. These balloons carried no fewer than two and a half million letters into the provinces of France. But the people in the provinces could not answer these letters, as no balloon could be relied upon to reach Paris. It is not surprising, therefore, that after the conclusion of the war, the French people should have made many efforts to construct balloons which could be guided to any particular destination. One such balloon was built in 1872, and another eleven years afterwards, but those balloons were not suitably constructed, and the engines and screw propellers were not powerful enough to take them against the wind.

It was only when motor cars were built in great numbers that people acquired sufficient experience to build very light and powerful engines suitable for propelling balloons. This shows how one class of inventors may help another class. A balloon which can be driven in any chosen direction is called an “air-ship.” Many such air-ships have been built within the last few years. They are shaped very much like a cigar. Some of them have cars made of light rods of steel or aluminium, and such air-ships have been navigated from one city to another over distances of sixty miles.

One of the most remarkable of these air-ships is that constructed by Count Zeppelin, a German officer (Fig. 76). It is 420 feet long, and 38 feet high. It is cylindrical in shape, and is covered with silk or gold-beater’s skin stretched over a stiff frame of aluminium rods. It is divided into sixteen air-tight compartments, so that if a hole should be cut in it at any point, the whole balloon would come to the ground very slowly. One such balloon travelled down the Rhine in August 1908 for over eleven hours. On its homeward journey it was caught in a storm and burnt up, but it was thought that it was built on a good plan, and the Germans at once set to work to build more ships of the same kind. In 1909 one of these made a trip from the Lake of Constance, in Switzerland, across Germany, to a place almost within sight of Berlin.

But while inventors were busy constructing balloons, the solution of the problem of flight was undertaken along an entirely different line.

Many men did not see why we should not to some extent imitate the flight of our successful rivals, the birds. It is true that from the earliest times many men have tried to make wings that could fly, but these attempts always ended in failure or disaster. The human body is too heavy in proportion to the power of the muscles. Birds are much stronger in proportion to their weight than we are. Their bones are built on a lighter plan, and there is no probability that we should be able to alter the construction of our own bones for the purposes of flight. Nor is that necessary. There are many ways of keeping a body afloat in air. Some birds can keep afloat for a long time without flapping their wings at all, and most people are acquainted with the trick of making a card fly through the air by giving it a rapid turning motion.

It was an American, Professor Langley, who first constructed a small machine which could fly through the air by means of its own mechanism. He found that the faster a flat surface is moved through the air in a horizontal direction, the less power it requires to keep it up. He concluded that if a machine is provided with horizontal wings, and driven very fast through the air, it will not require a very powerful engine to keep it up once a fairly high speed is attained. He launched his apparatus over a lake, and had the pleasure of seeing it fly for miles before it fell into the water. When this principle had been established other inventors straightway proceeded to apply it.

Two American motor manufacturers of the name of Orville and Wilbur Wright constructed a machine capable of carrying a man. Two years ago the first public trial of a flying machine was successfully made in Paris, when Mr. Santos Dumont, a young Brazilian balloonist, flew several hundred yards in a machine heavier than air. This machine consisted of a number of boxes open at both ends and covered with tightly-stretched canvas.

At that time it was found impossible to steer such a machine. But on December 30, 1907, Mr. Henry Farman succeeded at last in Paris in describing a complete circle in the air, covering a distance of more than half a mile, without once touching the ground. In July 1908 Mr. Farman remained in the air twenty minutes, covering a distance of eleven miles. This speed was afterwards increased to sixty miles an hour. Meanwhile Mr. Wilbur Wright had gone to France, and he soon eclipsed all the French records. On September 16, 1908, he flew a distance of a mile and a half with a passenger on board, and on September 21 he remained in the air one hour and a half, covering a distance of fifty-six miles. He remained in the air after darkness had set in, and it was strange to see his machine fly about like some gigantic night-bird. On the last day of 1908, Mr. Wright accomplished a flight lasting two hours twenty-three minutes, and covered a distance of nearly seventy-eight miles. This has since been exceeded both as regards distance and duration, and there seems every prospect that flights lasting several hours will soon be of common occurrence. On July 25, 1909, M. Louis Blériot, a French engineer, performed the great feat of crossing the English Channel from Calais to Dover in thirty-three minutes, in an aeroplane of his own construction. For ten minutes of the flight he was entirely out of sight of land.

Civilisation has now arrived at a new stage of immense importance. For the first time in its long history mankind has entered into full possession of the realm of air. We have now a new road which needs no repairing, and extends all round the globe. Our race enters on a new era, and nobody can say what great changes and improvements in our daily life are yet in store for us.

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