beleaguered city. As a colonel of cavalry, he
had been employed mainly in scouting duty throughout the war. He was
impressed now with the conviction that those globes, rising silently
into the air, above the enemy's cannon shot and drifting away to
safety would be the ideal scouts could they but return with their
intelligence. Was there no way of guiding these ships in the air, as
a ship in the ocean is guided? The young soldier was hardly home
from the war when he began to study the problem. He studied it
indeed so much to the exclusion of other military matters that in
1890 the General Staff abruptly dismissed him from his command. They
saw no reason why a major-general of cavalry should be mooning
around with balloons and kites like a schoolboy.

The dismissal hurt him, but deterred him in no way from the purpose
of his life. Indeed the fruit of his many years' study of aeronautic
conditions was ready for the gathering at this very moment. On the
surface of the picturesque Lake Constance, on the border line
between Germany and Switzerland, floated a huge shed, open to the
water and more than five hundred feet long. In it, nearing
completion, floated the first Zeppelin airship.

In the long patient study which the Count had given to his problem
he had reached the fixed conclusion that the basis of a practical
dirigible balloon must be a rigid frame over which the envelope
should be stretched. His experiments were made at the same time as
those of Santos-Dumont, and he could not be ignorant of the measure
of success which the younger man was attaining with the non-rigid
balloon. But it was a fact that all the serious accidents which
befell Santos-Dumont and most of the threatened accidents which he
narrowly escaped were fundamentally caused by the lack of rigidity
in his balloon. The immediate cause may have been a leaky valve
permitting the gas to escape, or a faulty air-pump which made prompt
filling of the ballonet impossible. But the effect of these flaws
was to deprive the balloon of its rigidity, cause it to buckle,
throwing the cordage out of gear, shifting stresses and strains,
and resulting in ultimate breakdown.

Whether he observed the vicissitudes of his rival or not, Count
Zeppelin determined that the advantages of a rigid frame counted for
more than the disadvantage of its weight. Moreover that disadvantage
could be compensated for by increasing the size, and therefore the
lifting power of the balloo