“Correct!” cried Harry. “We’ll rehearse for this evening. We shall depend on Jimmie to be the pilot, though!”

“Leave it to me!” declared the younger lad. “I know where the buoys are! I have them all located in my head!”

“But we must be mighty careful,” declared Ned. “We don’t know how much English these fellows understand. They must not suspect!”

“Mum’s the word!” put in Frank. “Everybody mum!”

First visiting the warehouse at the wharf, where they procured a quantity of supplies, such as might be needed to carry out the work which they were supposed to be doing, the lads proceeded aboard the submarine.

Upon their arrival they found a painter at work inscribing the vessel with identifying marks. He had proceeded so far as to place “U-1—” on each side of the vessel. Jimmie joyfully declared that fortune was playing into their hands in this respect, and that if something would compel the man to quit work for a while the disguise could be quickly made.

At Ned’s request Harry began fitting wires from the storage batteries to the motors used for propelling the vessel. The boys were startled to hear him utter an exclamation of dismay. They found upon inquiry that he had endeavored to strip the insulation from a wire by using his pocket knife and had cut a finger badly.

“Pooh, pooh!” stated Jimmie, upon discovering the wound. “Don’t make so much fuss over a little thing like that. We’ll soon have you fixed up. Here, just hold the wound closed with your other hand while I hunt up some bandages. You’ll be all right in a minute!”

But Harry declared that the wound pained excessively. He refused to treat the matter lightly, but gathered up the tools with which he had been working. These he deposited in a canvas bag in which they had been brought aboard the vessel.