But the Wondership, bearing the two boys who could not help laughing
heartily, although they feared serious consequences might come of the
accident, was winging its way onward out of earshot of the not
unnaturally indignant Ezra Perkins.

They passed Rayburn before Jack noticed a peculiar smell in the
atmosphere.

It was leaking gas. Then, for the first time, he recollected that the
farmer might have hit the gas bag above them with his double shots,
although, till then, there had been no indication that such was the
case.

He called Tom to the wheel, explaining his suspicions and clambered
out on the rigging to see if he could find any holes in the balloon.
It would have made a less steady boy dizzy and sick to stand on the
edge of the Wondership, clinging to one of the supports that held the
body of the craft to the gas-bag, while the whole affair plunged and
swayed five hundred feet above the earth. But Jack, used as he was to
navigating the air, felt none of these qualms.

His suspicions were speedily confirmed. There was a jagged hole in the
underbody of the balloon, from which gas was rushing. Jack's face grew
grave. The situation was dangerous.

He knew, as does every balloonist, that out-rushing gas can make an
electric spark in the atmosphere which, in turn, ignites the gas
itself, sometimes with fatal results. Experts in aëronautics attribute
the disasters befalling the long series of Zeppelins, the giant
German dirigibles, to this cause.