Latham--October 21, 1909--made a short flight, about 11 minutes, in the teeth of a 40 mile gale, at Blackpool, Eng. He used an Antoniette monoplane, and the official report says: "This exhibition of nerve, daring and ability is unparalled in the history of aviation."Farman--October 20, 1909--was in the air for 1 hour, 32 min., 16 seconds, travelling 47 miles, 1,184 yards, a duration record for England.
Paulhan--January 18, 1901--47 1/2 miles at the rate of 45 miles an hour, maintaining an altitude of from 1,000to 2,000 feet.
Expense of Producing Gas.
Gas is indispensable in the operation of dirigible balloons, and gas is expensive. Besides this it is not always possible to obtain it in sufficient quantities even in large cities, as the supply on hand is generally needed for regular customers. Such as can be had is either water or coal gas, neither of which is as efficient in lifting power as hydrogen.
Hydrogen is the lightest and consequently the most buoyant of all known gases. It is secured commercially by treating zinc or iron with dilute sulphuric or hydrochloric acid. The average cost may be safely placed at $10 per 1,000 feet so that, to inflate a balloon of the size of the Zeppelin, holding 460,000 cubic feet, would cost $4,600.
Proportions of Materials Required.
In making hydrogen gas it is customary to allow 20per cent for loss between the generation and the introduction of the gas into the balloon. Thus, while the formula calls for iron 28 times heavier than the weight of the hydrogen required, and acid 49 times heavier, the real quantities are 20 per cent greater. Hydrogen weighs about 0.09 ounce to the cubic foot. Consequently if we need say 450,000 cubic feet of gas we must have 2,531.25pounds in weight. To produce this, allowing for the 20percent loss, we must have 35 times its weight in iron, or over 44 tons. Of acid it would take 60 times the weight of the gas, or nearly 76 tons.
In Time of Emergency.
These figures are appalling, and under ordinary conditions would be prohibitive, but there are times when the balloon operator, unable to obtain water or coal gas, must foot the bills. In military maneuvers, where the field of operation is fixed, it is possible to furnish supplies of hydrogen gas in portable cylinders, but on long trips where sudden leakage or other cause makes descent in an unexpected spot unavoidable, it becomes a question of making your own hydrogen gas or deserting the balloon.
And when this occurs the balloonist is up against another serious proposition--can he find the necessary zinc or iron? Can he get the acid?
Balloons for Commercial Use.
Despite all this the balloon has its uses. If there is to be such a thing as aerial navigation in a commercial way--the carrying of freight and passengers--it will come through the employment of such monster balloons as Count Zeppelin is building. But even then the carrying capacity must of necessity be limited. The latest Zeppelin creation, a monster in size, is 450 feet long, and 42 1/2 feet in diameter. The dimensions are such as to make all other balloons look like pigmies; even many ocean-going steamers are much smaller, and yet its passenger capacity is very small. On its 36-hour flight in May, 1909, the Zeppelin, carried only eight passengers.
The speed, however, was quite respectable, 850 miles being covered in the 36 hours, a trifle over 23 miles an hour. The reserve buoyancy, that is the total lifting capacity aside from the weight of the airship and its equipment, is estimated at three tons.
