At best, however, the balloon as a means of locomotion is of more interest from a scientific than commercial standpoint. Increasing experience will determine the best disposition to be made in relation to a variety of points that are still open to discussion, such as the best methods of reducing resistances and increasing the efficiency of the motor. On the basis of the success already attained, calculations have been made which indicate that it may be quite possible in the near future to construct larger balloons that will travel in calm air at the rate of twenty-five or thirty miles an hour. Such air-ships, capable of ready direction at safe elevations, may serve important purposes in time of war. But for the public their use must long continue to be very limited. The enormous expense attendant upon the construction and manipulation of an aërostat capable of carrying even so few as a score of persons forbids competition with railroads and steamships. The high-tension battery, which is at present the most available source of energy to give motive power, has an effective life of only a few hours; and, even during this time, the cost of zinc and acid is far in excess of that of coal and water. For special purposes, where surface locomotion is impossible, and expenses can be sustained by great corporations or very wealthy individuals, the "dirigeable" balloon may, perhaps, win for itself an important place. The history of the application of science to art, especially during the last half-century, suggests caution in making sweeping denials, merely because our present knowledge does not enable us to grasp all the details of future development. Dr. Lardner's assertion, that no steamship would ever cross the Atlantic, may well remain fresh in our minds. The present competition between electricity and coal-gas as illuminating agents could scarcely have been foreseen in the days when coal-gas was itself comparatively a novelty. If we continue, as is probable, to attain cheaper methods of generating electricity, the balloon may grow in favor as the electric light has done, but without causing-the least commotion in the market for railroad stocks.
But, for the development of aëronautics as an art, we must continue to look to France, its earliest home. If stock companies are formed for the manufacture of air-ships, it must be first among those to whom the recent successes have already become a source of pride. Even as toys and as advertising media, balloons have always been more popular in France than elsewhere. The city of Paris has for years past included one or more large establishments devoted exclusively to the manufacture of them. Should "dirigeable" balloons ever become of commercial importance, enterprising Americans will be quick to imitate their French neighbors, and put upon our market all that the public may demand. The day is perhaps not far distant when at least a favored few in our own country may enjoy the luxury of summer afternoon excursions through the air, free from dust and cinders, and occasionally even vying with the birds in speed.
