either by ascending to a higher point or descending. In fact, he
may be content to come to the ground. Nor must the fact be
overlooked that while the enemy is trying to place the observer
hors de combat, he is revealing the position of his artillery,
and the observer is equally industrious in picking up the range
of the hostile guns for the benefit of his friends below.

When the captive balloon is aloft in a wind the chances of the
enemy picking up the range thereof are extremely slender, as it
is continually swinging to and fro. While there is always the
possibility of a shell bursting at such a lucky moment as to
demolish the aerial target, it is generally conceded to be
impossible to induce a shell to burst within 100 yards of a
balloon, no matter how skilfully the hostile battery may be
operated.

The value of the captive balloon has been demonstrated very
strikingly throughout the attack upon the entrenched German
positions in Flanders. Owing to the undulating character of the
dunes the "spotters" upon the British monitors and battle ships
are unable to obtain a sweeping view of the country. Accordingly
captive balloons are sent aloft in some cases from the deck of
the monitors, and in others from a suitable point upon the beach
itself. The aerial observer from his point of vantage is able to
pick up the positions of the German forces and artillery with
ease and to communicate the data thus gained to the British
vessels, although subjected to heavy and continuous hostile fire.
The difficulty of hitting a captive balloon has been graphically
emphasised, inasmuch as the German artillerists have failed to
bring down a solitary balloon. On the other hand the observer in