He gave Jack the command:
"Full speed ahead!"
CHAPTER XX.
THE TRAP IS SPRUNG.
As the three officers aboard the U-16 knew, British battleships and vessels of war of all descriptions had been stationed all along the Thames, many of them patrolling the very mouth of the river. But now, as Lord Hastings, Jack and Frank stood upon the bridge of the little submarine after it had entered the mouth of Thames, there was not a vessel of any kind to be seen in the darkness.
"Admiral Fischer's orders have been followed out, sir," said Jack in a low voice.
Lord Hastings nodded but made no reply.
Behind the U-16 the other German submarines followed closely, two abreast. Aboard each the men stood to their posts, awaiting the signal they expected at any minute. All the vessels moved along upon the surface. The officers, from their places upon the bridge, followed with their eyes the movements of the U-16, which displayed a small stern light to guide them on.
In case of danger Lord Hastings had been instructed to give immediate warning, that the vessels behind might have time to dive.