“But what are we going to do?” asked Frank, somewhat impatiently. “We are not going to stand by and look on, are we?”

Lord Hastings smiled.

“Don’t you worry,” he said quietly. “We’ll take our part, whatever it may be. We’ll go below now.”

The three descended. The conning tower and bridge were closed behind them, and soon the tanks were opened. The D-16 submerged until the top of her periscope barely protruded above the edge of the water.

Lord Hastings, Frank and Jack took turns watching the approach of the two fleets, now that they were in range of the periscope; and it was while the latter was at the instrument that sudden signs of commotion became noticeable on the German vessels. At the same instant Jack perceived that the British ships had increased their stride, and were making directly for the Germans.

“They have sighted each other, sir,” he cried, turning to Lord Hastings in great excitement.

Lord Hastings sprang to the periscope.

“And the Germans are turning to run,” he said, after a quick glance.

It was true. The German commander, realizing that he was probably no match for the powerful British squadron, had no mind to give battle when the odds were as nearly even as they were now. Evidently he had more confidence in the power of his enemy than he had in his own. Therefore, immediately the British fleet was sighted, he gave the command to come about and make for the protection of the mined area about Heligoland at full speed.

But the time lost in coming about was to prove a severe blow to the Germans. The British fleet, led by the Tiger, Admiral Beatty’s flagship, had sighted its prey, and was making after it at full speed.