It suggested an idea and I hurried, shouting.

One of the men, seated in it, was evidently explaining its working to the others.

“Wait,” he said, as he saw me running down the shore, waving and shouting at them.  “Let’s see what this fellow wants.”

It was, as I soon learned, the famous Captain Burnside, of the United States Aerial Corps.  Breathless, I told him what I had seen and that we were all friends of Woodward’s.

Burnside thought a moment, and quickly made up his mind.

“Come—­quick—­jump up here with me,” he called.  Then to the other men, “I’ll be back soon.  Wait here.  Let her go!”

I had jumped up and they spun the propeller.  The hydroaeroplane feathered along the water, throwing a cloud of white spray, then slowly rose in the air.

The sensation of flying was delightful, as the fresh morning wind cut our faces.  We seemed to be hardly moving.  It was the earth or rather the water that rushed past under us.  But I forgot all about my sensations in my anxiety for Elaine.

As we rose we could see over the curve in the shore.

“Look!” I exclaimed, straining my eyes.  “She’s overboard.  There’s a motor-boat after her.  Faster—­over that way!”

“Yes, yes,” shouted Burnside above the roar of the engine which almost made conversation impossible.

He shifted the planes a bit and crowded on more speed.

The men in the boat saw us.  One figure, tall, muffled, had a familiar look, but I could not place it and in the excitement of the chase had no chance to try.  But I could see that he saw us and was angry.  Apparently the man gave orders to turn, for the boat swung around just as we swooped down and ran along the water.

Elaine was exhausted.  Would we be in time?

We planed along the water, while the motor-boat sped off with its baffled passengers.  Finally we stopped, in a cloud of spray.

Together, Burnside and I reached down and caught Elaine, not a moment too soon, dragging her into the boat of the hydroaeroplane.

If we had not had all we could do, we might have heard a shout of encouragement and relief from the hill where Woodward and Arnold and the rest were watching anxiously.

I threw my coat about her, as the brave girl heroically clung to us, half conscious.

“Oh—­Walter,” she murmured, “you were just in time.”

“I wish I could have been sooner,” I apologized.

“They—­they didn’t cut the cable—­did they?” she asked, as we rose from the water again, bearing her now to safety.  “I did my best.”

CHAPTER XI

THE WIRELESS DETECTIVE

Del Mar made his way cautiously along the bank of a little river at the mouth of which he left the boat after escaping from the little steamer.

Quite evidently he was worried by the failure to cut the great Atlantic cable and he was eager to see whether any leak had occurred in the organization which, as secret foreign agent, he had so carefully built up in America.