While wonderful success has attended the development of the dirigible (steerable) balloon the most ardent advocates of this form of aerial navigation admit that it has serious drawbacks. Some of these may be described as follows:
Expense and Other Items.
Great Initial Expense.--The modern dirigible balloon costs a fortune. The Zeppelin, for instance, costs more than $100,000 (these are official figures).
Expense of Inflation.--Gas evaporates rapidly, and a balloon must be re-inflated, or partially re-inflated, every time it is used. The Zeppelin holds 460,000 cubic feet of gas which, even at $1 per thousand, would cost $460.
Difficulty of Obtaining Gas.--If a balloon suddenly becomes deflated, by accident or atmospheric conditions, far from a source of gas supply, it is practically worthless.
Gas must be piped to it, or the balloon carted to the gas house--an expensive proceeding in either event.
Lack of Speed and Control.
Lack of Speed.--Under the most favorable conditions the maximum speed of a balloon is 30 miles an hour.
Its great bulk makes the high speed attained by flying machines impossible.
Difficulty of Control.--While the modern dirigible balloon is readily handled in calm or light winds, its bulk makes it difficult to control in heavy winds.
The Element of Danger.--Numerous balloons have been destroyed by lightning and similar causes. One of the largest of the Zeppelins was thus lost at Stuttgart in 1908.
Some Balloon Performances.
It is only a matter of fairness to state that, under favorable conditions, some very creditable records have been made with modern balloons, viz:
November 23d, 1907, the French dirigible Patrie, travelled 187 miles in 6 hours and 45 minutes against a light wind. This was a little over 28 miles an hour.
The Clement-Bayard, another French machine, sold to the Russian government, made a trip of 125 miles at a rate of 27 miles an hour.
Zeppelin No. 3, carrying eight passengers, and having a total lifting capacity of 5,500 pounds of ballast in addition to passengers, weight of equipment, etc., was tested in October, 1906, and made 67 miles in 2 hours and 17 minutes, about 30 miles an hour.
These are the best balloon trips on record, and show forcefully the limitations of speed, the greatest being not over 30 miles an hour.
Speed of Flying Machines.
Opposed to the balloon performances we have flying machine trips (of authentic records) as follows:
Bleriot--monoplane--in 1908--52 miles an hour.
Delagrange--June 22, 1908--10 1/2 miles in 16 minutes, approximately 42 miles an hour.
Wrights--October, 1905--the machine was then in its infancy--24 miles in 38 minutes, approximately 44 miles an hour. On December 31, 1908, the Wrights made 77miles in 2 hours and 20 minutes.
Lambert, a pupil of the Wrights, and using a Wright biplane, on October 18, 1909, covered 29.82 miles in 49minutes and 39 seconds, being at the rate of 36 miles an hour. This flight was made at a height of 1,312 feet.
