Speedy as the _Snowbird_ was, she could not get out from under the
shadow of the strange aeroplane. That was driven at a sharp angle down
upon the boys' flying machine, and it seemed to all those in the lower
'plane that a collision was imminent.

The thunder fairly deafened them all. Around them rolled the mists and
the wind shrieked through the stays of the aeroplane and shook the
structure like a dog worrying a bone.

Down they fell, and in an instant the rushing rain, emptied in a torrent
from the clouds, swept about them, saturating their garments and beating
the flying machine itself toward the distant earth.

During the next few moments Jack Darrow, Mark Sampson, and their
companions were in as grave peril as had ever threatened them in their
eventful lives.

The torrents of water all but beat the flying machine to the earth--and
to be dashed down from such a height spelled death to all and
destruction to the aeroplane.

Jack, however, had been taught to keep cool in moments of danger, and
he realized that their lives depended entirely upon his handling of
the great machine. They had descended below the level of the storm-cloud
at a most inopportune moment. They were caught in the midst of a
veritable cloudburst.

Shaken desperately by the wind, and beaten upon by tons upon tons of
water, it was a wonder that the great planes, or wings, of the flying
machine were not torn away. All Jack could do was to guide her the