nch balloonists by the events of 1870-1, and which all the devotion
and science of the Tissandier brothers failed to accomplish. To-day
the problem may be set with better hope of success. All the essential
difficulties may be revived by the marking out of a hostile zone around
the town that must be entered; from beyond the outer edge of this zone,
then, the airship will rise and take its flight--across it.

'Will the airship be able to rise out of rifle range? I have always
been the first to insist that the normal place of the airship is in low
altitudes, and I shall have written this book to little purpose if
I have not shown the reader the real dangers attending any brusque
vertical mounting to considerable heights. For this we have the terrible
Severo accident before our eyes. In particular, I have expressed
astonishment at hearing of experimenters rising to these altitudes
without adequate purpose in their early stages of experience with
dirigible balloons. All this is very different, however, from a
reasoned, cautious mounting, whose necessity has been foreseen and
prepared for.'

Probably owing to the fact that his engines were not of sufficient
power, Santos-Dumont cannot be said to have solved the problem of the
military airship, although the French Government bought one of his
vessels. At the same time, he accomplished much in furthering and
inciting experiment with dirigible airships, and he will always rank
high among the pioneers of aerostation. His experiments might have
gone further had not the Wright brothers' success in America and French
interest in the problem of the heavier-than-air machine turned him from
the study of dirigibles to that of the aeroplane, in which also he takes
high rank among the pioneers, leaving the construction of a successful
military dirigible to such men as the Lebaudy brothers, Major Parseval,
and Zeppelin.

IV. THE MILITARY DIRIGIBLE

Although French and German experiment in connection with the production
of an airship which should be suitable for military purposes proceeded
side by side, it is necessary to outline the development in the two
countries separately, owing to the differing character of the work
carried out. So far as France is concerned, experiment began with the
Lebaudy brothers, originally sugar refiners, who turned their energies
to airship construction in 1899. Three years of work went to the
production of their first vessel, which was launched in 1