It was the work of but an instant to convey the message to Ned.  The latter called Mr. Damon to relieve him in the motor room, and, a few seconds later, Ned had switched on the electricity.  By means of the lazy-tongs, and the toggle joints, the bank clerk lifted the lantern over until the powerful beam from it was projected straight down into the seething waters of the lake.

“Do you see anything?” asked Mr. Damon from the motor room, at one side of which Ned stood to operate the lantern.

“Nothing but white-caps,” was the answer.  “It’s a fearful storm.”

Once more came the series of shrill whistles, and the confused calling of voices.  Ned opened a window, in order to hear more plainly.  As the whistle tooted again he could locate the sound, and, by swinging the rays of the searchlight to and fro he finally picked up the craft.

“There she is!” he cried, peering down through the plate glass window in the floor of the motor room.  “It’s a small gasolene boat, and there are several men in her!  She’s having a hard time.”

“Can we rescue them?” asked Mr. Damon.

“If anybody can, Tom Swift will,” was Ned’s reply.  Then came a whistle from the speaking tube, that led to the pilot house.

“What is it?” asked Ned, putting the tube to his ear.

“Stand by for a rescue!” ordered Tom, who had also, through a window in the floor of the pilot house, seen the hapless motor boat.  The men in it were frantically waving their hands to those on the airship.  “I’m going down as close as I dare,” went on Tom.  “You watch, and when it’s time, have Koku drop from the stern a long, knotted rope.  That will he a sort of ladder, and they can make it fast to their boat and climb up, hand over hand.  It’s the only plan.”

“Good!” cried Ned.  “Send Koku to me.  Can you manage alone in the pilot house?”

“Yes,” came back the answer through the tube.

Koku came back on the run, and was soon tying knots in a strong rope.  Meanwhile Ned kept the light on the tossing boat, while Tom, through a megaphone had called to the men to stand by to be rescued.  The whistle frantically tooted their thanks.

Koku went out on the after deck, and, having made the knotted rope fast, dropped the end overboard.  Then began a difficult feature of airship steering.  Tom, looking down through the glass, watched the boat in the glare of the light.  Now coming forward, now reversing against the rush of the wind; now going up, and now down, the young inventor so directed the course of his airship so that, finally, the rope dragged squarely across the tossing boat.

In a trice the men grabbed it, and made it fast.  Then Tom had another difficult task—­that of not allowing the rope to become taut, or the drag of the boat, and the uplift of the airship might have snapped it in twain.  But he handled his delicate craft of the air as confidently as the captain of a big liner brings her skillfully to the deck against wind and tide.