For a time the possibilities of the motor-bicycle so occupied
Bert's mind that he remained regardless of the new direction in
which the striving soul of man was finding exercise and
refreshment. He failed to observe that the type of motor-car,
like the type of bicycle, was settling-down and losing its
adventurous quality. Indeed, it is as true as it is remarkable
that Tom was the first to observe the new development. But his
gardening made him attentive to the heavens, and the proximity of
the Bun Hill gas-works and the Crystal Palace, from which ascents
were continually being made, and presently the descent of ballast
upon his potatoes, conspired to bear in upon his unwilling mind
the fact that the Goddess of Change was turning her disturbing
attention to the sky. The first great boom in aeronautics was
beginning.

Grubb and Bert heard of it in a music-hall, then it was driven
home to their minds by the cinematograph, then Bert's imagination
was stimulated by a sixpenny edition of that aeronautic classic,
Mr. George Griffith's "Clipper of the Clouds," and so the thing
really got hold of them.

At first the most obvious aspect was the multiplication of
balloons. The sky of Bun Hill began to be infested by balloons.
On Wednesday and Saturday afternoons particularly you could
scarcely look skyward for a quarter of an hour without
discovering a balloon somewhere. And then one bright day Bert,
motoring toward Croydon, was arrested by the insurgence of a
huge, bolster-shaped monster from the Crystal Palace grounds, and
obliged to dismount and watch it. It was like a bolster with a
broken nose, and below it, and comparatively small, was a stiff