“Reverse the engine!” shouted McClure.  “We must have run upon a sandy shoal.”

Frantically he rang the engine room to back away.  But the order came too late.  With a slow ringing noise that plainly bespoke the grating of the ship’s keel on the bed of the ocean the submarine slid forward and then came to a dead stop, quivering in every steel plate from the tremendous throbbing of her engines.

“Great Scott, we’ve run aground!” exclaimed McClure as he stood wild-eyed in the conning tower.

Jack was despatched to the engine room for a report from Chief Engineer Blaine.  He returned in a moment to say that the ship’s engines were reversed and the propeller shafts revolving to the limit of the ship’s power.  Nevertheless, it was only too evident that the Dewey was enmeshed in a treacherous shoal from which she was unable to extricate herself.

Officer Binns was ordered to throw off all possible ballast.

One by one the tanks were emptied.  The air pumps were working valiantly but at each discharge of water ballast the officers of the stranded vessel waited in vain for the welcome “lift” that would tell them the ship was floating free again.  The last ballast tank had now been emptied and the depth dial still showed eighty-four feet.

“Looks as though we were stuck, all right,” was McClure’s solitary comment as he gazed again at the depth dial.

The engines now were shut down, the air pumps had ceased working.  There was not a sound throughout the submersible, except the low drone of the electric fans that swept the air along the passageways.  Every man waited in stoical silence a further word from his chief.

“Jonah had nothing on us,” cried Bill Witt grinning, as the group of boys retreated down the passageway leading forward from the conning tower into the main torpedo compartment.  Lieutenant McClure and his officers were conferring together over the Dewey’s dilemma.

“This ship is no fish,” ventured Ted timidly, his mind engrossed in the new danger that threatened.

“Well, it’s a whale of a submarine, isn’t it?” continued Bill in a brave effort to be funny.

Ted agreed, but was in no humor for joking, and hurried amidships to join Jack, who had remained within call of his commander.

For some moments the boys discussed the predicament of the Dewey, the unfortunate circumstances that had led her aground, and the possibilities of being floated again.  Jack confided to his chum the fact that he had overheard Lieutenant McClure say the Dewey probably had ventured too close in shore and had run afoul of a sand bar.

“What’s the next move?” queried Ted.

“You’ve got me, chum; I don’t know what they will try next,” answered Jack, feeling a bit glum despite his natural cheerfulness.

Lieutenant McClure and his officers—–­Cleary, Binns, and Blaine—–­were now making an inspection of the Dewey fore and aft.  As they returned amidships the boys overheard snatches of the conversation.