Whether the submarine had expended her last torpedo, or whether having missed what she intended for a vital shot she deemed there was not time to launch another and had sunk out of sight, or whether she were disabled, were questions perhaps never to be answered.

At any rate, the approach of the destroyer, which came on with amazing speed, served to make the Jeanne comparatively safe.  The lifeboats were emptied of their passengers, and once more there was a feeling of comparative safety as the passengers again thronged the decks.

On came the destroyer.  She proved to be one of Uncle Sam’s boats, and the joy with which she was greeted was vociferous and perhaps a little hysterical.  She had learned by wireless of the appearance of the French craft in the danger zone, and had come to fulfill her mission.  She had been delayed by a slight accident, or she would have been on hand when the submarine first approached.

The wireless message that had come just as the German craft appeared had been from the destroyer, to bid those aboard the Jeanne have no fear, for help was on the way.  And soon after the grim and swift craft from the United States had begun to slide along beside the Jeanne two more destroyers, one of them British, made their appearance, coming up with the speed of ocean greyhounds.

There was great rejoicing among the passengers, and much credit was given the lookout for his promptness in reporting a sight of the submarine.  Formal thanks were extended to the gun crews for their efficient work, without which the undersea boat might have accomplished her purpose.  Nor were the boiler room and engineer forces forgotten, for it was because of the sudden burst of speed on the part of the Jeanne that she escaped that one torpedo at least.

“Now we’ll be all right,” Charlie said, as he helped his friends make a few pictures of the approach and the convoying of the destroyers to add to the views they had of the submarine and her defeat—­temporary defeat it might prove, but, none the less, a defeat.

“Well, hardly all right,” remarked Blake, as the camera was dismounted.  “We’re still in the danger zone, and the Huns won’t let slip any chance to do us harm.  But I guess we have more of a chance for our white alley than we had before.”

Though the French ship was now protected by the three convoying vessels, the crews of which kept a sharp watch on all sides for the presence of more submarines, there was still plenty of danger, and this was felt by all.

At any moment a submarine, approaching below the surface with only her periscope showing—­and this made a mark exceedingly hard to see and hit—­might launch a torpedo, not only at the merchant-man but at one of the destroyers.

“It’s like sleeping over a case of dynamite,” observed Joe, as he and his chums went below.  “I’d rather be on the war front.  You can at least see and hear shells coming.”