A Machine for Testing the Lifting Power of Aëroplanes.
In this machine power is transmitted from the horizontal main shaft and upward through the vertical steel spindle and through the two members of the long arm. A is a scale showing miles per hour and B a scale divided into feet per minute; C, Dynamometer for recording the push of screw; D, Dynamometer showing the lift of the aeroplane.
The ordinary balloon has played a much more important part in actual warfare than most people realize. A balloon corps was organized in France as early as 1794, when balloons were built for each of the Republican armies. One of these balloons, measuring thirty feet in diameter, was sent up near Mayence, to gain a view of the Austrian army. The balloon was held captive by two ropes, and an officer in the car wrote his observations, weighted the letters, and dropped them overboard. The Austrians were furious at this spying, and opened fire, but the ropes were lengthened and the balloon rose to a height of 1300 feet, where it was out of range. Several years later balloons were again used in battles by the French against the Austrians, who were so angry with the new machine that they declared that any balloonist captured would be shot. For a long time afterward, however, this method of warfare was neglected, and even Napoleon could not see its value, and closed the aëronautical school and disbanded the corps.
The use of the balloon was revived in America during the Civil War, and proved to be so valuable that no great war has since been fought without it. During the attack on Richmond, a number of balloons were sent up daily by the Federal Army to overlook the besieged city. From a point eight miles away, valuable information was gained as to the position of the troops and the earthworks. A telegraph apparatus was taken up and messages were sent directly from the clouds, almost over Richmond to Washington.
In the Spanish-American War in 1898, the balloon was again called into use. One ascent was made before Santiago, Cuba, and the position of the various Spanish forces were observed and reported. Another was sent up at El Paso, less than 2000 feet from the Spanish trenches, and the position of the Spanish troops on San Juan Hill was discovered. The balloon was finally brought down by the Spanish guns.
During the siege of Paris in 1870, balloons were used successfully to escape from the city. Some sixty-six of them, carrying 168 passengers, succeeded in passing over the German armies. The French army has also made good use of the balloon in the wars in Madagascar, and several English balloon corps were engaged with the British army during the Boer War.
For ordinary military work, balloons of three sizes are used, a large balloon for forts, the regular war balloon, and an auxiliary for field work. The large balloon holds 34,500 cubic feet of gas and is only used above fortifications. The regular field balloon is thirty-three feet in diameter, and holds 19,000 cubic feet of gas. It is designed to carry two passengers to a height of 1650 feet. The auxiliary balloon is considerably smaller, holding only 9200 cubic feet of gas, and carrying but one passenger. It is much easier to handle on long marches, and, of course, may be filled and sent aloft in much less time.
The balloons are usually filled from cylinders, which may be hurried across country in carts or automobiles. There is, besides, a regular field gas generator, readily packed up and carried about, which will fill an ordinary balloon in from fifteen to twenty minutes. To resist aërial attacks, a special armored automobile has been adopted by some European armies, carrying a gun which may be aimed upward and at any angle. Despite its weight, the automobile will travel at the rate of forty miles an hour. The recent developments of the dirigible war balloon has rendered the free balloon practically obsolete, and it is unlikely that it will ever again be used in actual warfare.
The United States has been the first country to adopt the aëroplane as a weapon of warfare. After the successful flights of the Wright Brothers, the War Department purchased one of their aëroplanes, and several officers were instructed in driving it. Before being accepted, the Wrights were required to make a flight of ten miles over a rough, mountainous country near Washington, and return without alighting. The test, which was highly successful, was witnessed by President Taft and many representatives of the Government. In the event of war, the United States Government could quickly mobilize a formidable fleet of aëroplanes, and man them with experienced aviators.