Page:Collier's New Encyclopedia v. 01.djvu/67

AERONAUTICS Jeffries, crossed the English Channel from Dover and landed at Calais.

Up to this time ballooning had been carried on as an adventure or a sport. Scientists intervened, and sought through this novel medium to ascertain scientific data that so far had been based only on conjecture. The first ascent with this object in view was made in 1804 from Paris. It was learned that as the balloon rose the air became drier and that at 23,000 feet the chemical composition of the air did not vary from that at the surface of the earth.

The two most notable ascents recorded were those made by Glaisher and Coxwell in September of 1862 and of Berson and Suring, July 31, 1901. In the former ascent it was claimed that a height of seven miles was reached, but this was not susceptible of proof, because at 29,000 feet Glaisher lost consciousness. The ascent continued until Coxwell, who was almost paralyzed, opened the valve with his teeth, and the balloon finally landed with both passengers safe. More reliable figures as to altitude were those recorded by Berson and Suring, when they ascended from Berlin to a height of 6.7 miles. This is the greatest height that has ever been attained by men in a balloon, although it was exceeded by Major Schroeder of America who reached an altitude of 33,113 feet in an airplane.

Within the last twenty-five years, many notable balloon flights have been recorded, some of them negotiated with great risk to the aerial adventurers. Up to the present century, the longest flight was that made by M. Goddard, who traveled the distance of 1,032 miles from Leipsic to Wilna in a little over twenty-four hours. In 1900 De la Vaulx covered the distance from Vincennes, France, to Korosticheff, Russia, 1,193 miles, in 35¾ hours. In 1912, Dubonnet and Dupont made a trip of 1,211 miles in the "Condor II." But a still longer flight was that of Rumpelmayer, who on March 24, 1913, completed a journey of 1,493 miles from Paris to the vicinity of Kharkoff, Russia. In America, Hawley and Post the balloon "America" drifted 1,172 miles from St. Louis, landing in a dense Canadian forest.

The great defect of the globular balloon that was recognized almost from the date of its invention was its inability to be propelled or steered. The huge machine was wholly at the mercy of the winds. It could rise by lightening its load; it could descend by releasing its gas; but it could not choose its direction of flight. No goal except that of altitude could be achieved. The devices that were originally employed to supply this need were such as to almost provoke a smile. Blanchard, the English aeronaut, tried to use oars and a rudder, but failed. Another device was the making of a large hole in the side of the balloon, through which the gas escaping was by reaction to force the balloon forward. What doomed all these contrivances to failure in advance was the spherical shape of the balloon. The surface offered to the wind was too great to be overcome. It was only when the shape of the balloon was changed that propulsion and direction became possible.

The first dirigible balloon that could be called a success was the invention of Giffard„ a Frenchman. He constructed a spindle-shaped bag that was 143 feet long, 39 feet in diameter, and had a capacity of 75,000 cubic feet. From beneath the bag hung a car that carried a 3-horse-power engine that drove a three-blade propeller at the rate of 110