Page:Popular Science Monthly Volume 64.djvu/393

Rh to design it so that the results shall not be disappointing. Those inventors who expect to attain 70 to 100 miles an hour by some happy combination do not know what they are talking about.

It is interesting to speculate which of the above-mentioned navigable balloons would, if competing, stand a chance of winning the $100,000 prize which has been offered by the St. Louis Exposition of 1904. So far as can now be discerned, the only vessels which are likely to develop the required minimum speed of 20 miles an hour over the ground, which speed really requires about 25 miles an hour through the air as there will almost invariably be some wind, will be the Santos Dumont No. 7, the Lebaudy and the Deutsch air-ships, all of them French. The English vessels of Spencer and of Beedle are too small to lift sufficient power to drive them at 25 miles an hour. The balloon of Dr. Barton might gain this speed if it were not 40 feet in diameter, besides being loaded down with aeroplanes, and it remains to be seen what will be the effect of this combination. The American air-ships all seem to be too small to lift enough power to give them the required speed save the Stanley air-ship, 228 feet by 56 feet in diameter, begun in San Francisco. Should this be completed in time, and should the weights be kept approximately near those stated in the circulars, it might have a chance to obtain 25 miles an hour, but it would need more than three times the 50 horse power contemplated in order to do so, and the weight of the aluminum shell and framing would probably absorb much of the lifting power.

If the aeronautical contest at St. Louis were scheduled to take place a few years later, thus giving time to consummate recent success, it is not improbable that the main prize would be carried off by a flying machine. This yet lacks the safe flotation in the air which appertains to balloons, but it promises to be eventually very much faster.

The writer found, somewhat to his surprise, when on a visit to Paris last April, that a decided reaction has set in among the French against balloons. It seemed to be realized that the limit of speed had been nearly reached for the present, and that but small utility was to be expected from navigable balloons. They must be large, costly and require expensive housing, while they are slow and frail and carry very small loads. As commercial carriers they are not to be thought of, but they may be useful in war and in exploration.

Hence the French are turning their thoughts towards aviation and propose to repeat some of the experiments with gliding machines which have taken place in America. Even Colonel Renard, the celebrated pioneer of the modern navigable balloon, is now said to have become a convert to aviation and to say that the time has come to try the