AERONAUTICS, History' of. There has always been interest by philosophers and scientists in aerial navigation, and the problem was given serious thought by the first physicists of whom history gives account. To those not versed, who consider mechanical flight to have been developed within the past few centuries, it may seem surprising that principles estab lished by Archimedes, a Grecian mathemati cian who lived several centuries before the Christian era, are now followed and are suc cessfully applied in the most modern types. Students of ancient history are familiar with the mythological legend of Dwdalus, Grecian sculptor, and Icarus, his companion, who made a flight with wings fashioned by the former, and which, like so many actual flights, ended in disaster. Icarus, feeling over-confident in his own ability, flew too near the sun, the heat of which melted the wax attaching the wings to his body, and precipitated him into the sea, which sea was named the Icarian Sea to com memorate the event.
The first human being whom history records as having actually risked his life in demon strating his theories was Fauste Veranzio, who in 1617 made a descent from a high tower in Venice supported by a primitive parachute con sisting of a square framework covered with canvas. There were no imitators of his methods for many years though there were many suggestions made, most of them fanciful and impracticable. Among these might be mentioned the creation of Francesco De Lana, which was to be sustained by four large hollow metal spheres, from the interior of which all the air was to be exhausted, the theory being that as the spheres were lighter than air they would float in space as does a cork upon water. It seems that even at this early period there was knowledge that air had a .definite weight just as any liquid or solid, and that bodies lighter than air would rise as would a chip of wood when released under the surface of the water. These metal spheres of De Lana's were held in fixed relation by a framework of wood and a boat or body was provided with oars and sails by which it was to be propelled. While his ideas and theories on the problem were very much the same as those which determine the aerostats, or balloons of the present day, there existed obvious practical difficulties and the proposed airship remained as a rather fancifully designed drawing.
It is interesting to note at this point a form of glider constructed by Karl Friedrich Meer win, a German architect who lived early in the 18th century, which proves that even at that date considerable was known of the law of resistance. The engineer calculated that an exposed area of 130 feet would be necessary to support a man's weight, or a weight equiv alent to that of an average man, and this is a very good approximation of the truth as will be pointed out later. This inventor suggested that experiments be carried out over water to prevent serious accidents, which suggestion has been carried out in more recent years by Count Zeppelin over the waters of Lake Con stance and in the experiments of Langley over the Potomac River at Washington, D. C.
Aerostats.— The discovery in 1776 by Cavendish of hydrogen gas and his proof that it was lighter than air represents the beginning of actual aerial navigation. It was natural for philosophers to conclude that if containers of sufficient dimension but little weight were filled with this gas they would rise in the air. Ex periments were made by filling soap bubbles with this gas, which, however, escaped so rapidly little was learned. Then attempts were made to fill bladders and paper bags, but again the gas escaped through the pores almost as fast as it was let into them.
The credit of inventing the aerostatic air ship or balloon is given to the Montgolfier brothers, Stephen and Joseph, who were the sons of a wealthy manufacturer of paper bags. These experimenters, after many trials, made a paper balloon of 700 cubic feet capacity, which was filled with smoke and heated air from a fire fed with wet straw and wool under the open mouth, and which surprised the multitude when it rose to the height of 1,900 feet. This was on 5 June 1783. Not long after this ex periment Faugus de St. Fond started a sub scription to raise the funds necessary to build a balloon, with the principal work of which the scientist, Charles, was interested. Through years of laboratory experience Charles was thoroughly familiar with the properties of hydrogen, and with the fact in his mind that heated air had enabled the Montgolfier brothers to ascend their balloon to a height of 1,000 feet, he concluded that by using a gas lighter than air, his success would be greater.