Toward midnight the airship stood at an altitude of 5,280 feet in the air, when a jet-black cloud was encountered.
She was rushing toward it, and the cloud ran at her.
In a moment she was shot into the middle of it.
Her entrance into the cloud seemed to agitate it.
At first the motion was easy, but gradually it intensified, and began to shake and toss the Jove.
Then it began to whirl.
Soon this motion grew furious.
The airship was checked in its flight, and spun around with the gyrating cloud at an appalling speed.
“A cyclone!” gasped Frank, in alarm.
“Look out!” yelled Barney. “We’re upsettin’!”