The power having already been shut off, the Hawk was proceeding only under the headway given by the now dormant motor.
This was sufficient not only to turn her, but also to carry her downward so that the bottom of the car swept the roof.
As they passed one of the chimneys, Ferral dropped the loop of the rope over its top, and laid back. His pull halted the air ship.
In a twinkling, Matt was over the rail and standing beside the car. He held out his hand to the girl, and she ran toward him, with a cry of joy and thankfulness.
At that precise moment, Matt, out of the tails of his eyes, saw a head appearing through the open skylight. Grasping Helen's arm, he hurried her toward the air ship.
"Step lively, mate!" cried Dick, as Matt assisted the girl into the car.
No matter how swiftly Matt hurried, it was certain that the man coming through the skylight would reach the roof in time to interfere with the two boys before they could get away.
Matt realized that, and so did Ferral. The man, who was now head-and-shoulders above the roof top, was Whipple, the most desperate member of the gang.
Whipple, who was undoubtedly amazed to see Helen all but rescued when, quite likely, he supposed her safe in some room below, gave a bellow of rage and fury.
"That'll do you, King!" he roared. "Ye're not goin' ter hike off with the girl in any such way as this!"