The light of lanterns showed that the men of one gang were searching thoroughly all along the top of the wall. Once in a while a man belonging to the beach patrol passed the chief engineer and the superintendent, reporting only that no signs of Harry had been found.
An hour thus passed. Then, from over the water, as the lantern-bearing searchers were returning, a dull explosion boomed across the water.
"Great Scott!" quivered Tom. "There they go at it again, Mr. Renshaw!
Another section of the retaining wall has gone—-blown up!"
CHAPTER V
WANTED—-DAYLIGHT AND DIVERS
In a trice the foreman of the gang on the wall wheeled his men about, running them out seaward toward the scene of the latest explosion. That much was plain from the twinkling of the rapidly-moving lanterns.
"Come on, Renshaw!" Tom shouted. "You, too, Nicolas. You can pull an oar."
Reade was already racing out on to the small dock. He all but threw himself into a rowboat that lay tied alongside.
"Cast off and get in," Tom ordered his companions, as he pushed out a pair of oars. "Nicolas, you're also good with a pair of oars. Mr. Renshaw, you take the tiller. Inform me instantly when you see the first gleam of the 'Morton's' search-light. Evarts ought to have caught the scoundrels this time. Evidently he's been cruising softly without showing a light."
Mr. Renshaw gathered up the tiller ropes as Tom pushed off from the dock. Then the chief engineer addressed himself to the task of rowing. His firm muscles, working at their best, shot the little craft ahead. Nicolas, at the bow oars, did his best to keep up with his chief in the matter of rowing, though the Mexican was neither an oarsman nor an athlete.