“Dot—­dash—­dash—­dot,” exclaimed Rob.

“That’s the letter P,” put in Merritt.

“That’s right, old man,” shouted Rob, slapping him on the back, “and we’ve found Joe Digby.  That smoke signal spelled Help in the Morse code.”

“You’re right,” shouted Merritt, “come on, Cap, come on, boys, we’ve got to get a move on and get it on quick!”

They dashed toward the dinghy and a few seconds later had once more embarked and were speeding toward the desolate and forsaken bungalow.  Somehow they managed to get ashore in the dinghy without anyone being spilled over the side in their desperate hurry and a minute later were pounding at the door.

“Joe—­Joe Digby,” shouted Rob in a strange, strained voice.

“Here,” came back the answer in a feeble tone, “oh, boys, I’m glad you’ve come.”

Furiously Rob shook the door.

“It’s locked,” came the voice from inside, “I tried to break it down.  Too weak, I guess.  Try the shutters.”

At each window in turn the Boy Scouts sought to effect an entrance, but in vain.  The owner of the place had screwed up the window coverings too tightly for them to be opened without tools.

The rescue party came to a momentary halt.

“I’ve got it,” shouted the captain suddenly, “we’ll have him out uv there in two shakes uv a drake’s tail.”

He produced his formidable old pistol and waved it grimly.

“Come on, boys,” he yelled, darting round to the front of the house—­the side on which the door was.

“What are you going to do?” demanded Rob, as much mystified as the rest at the old eccentric actions.

“Watch me,” grinned the captain as he gained the door.

“Stand clear!” he bawled at the top of his lungs, “stand clear uv the door inside there, Joe!”

“All right,” came back the reply, “I’m in a corner.”

“Now, stand by ter receive boarders!” roared the veteran as he placed the muzzle weapon at the lock and pulled the trigger.

“Bang!”

There was a roaring explosion from the wide mouthed weapon and a cloud of smoke filled the air.  But simultaneously there came a sound of ripping, tearing and splintering and the lock of the door, shot clean out by the heavy charge, clattered down to the floor on the inside of the room.

An instant later Joe Digby, pale and trembling from privation, surprise and happiness all mingled in one, was in the midst of his friends and fellow scouts.

“I don’t know what made me think of it,” he explained in answer to eager questions about the smoke telegraph message.  “It was what the books call an inspiration, I guess.  There were plenty of loose boards—­fragments of old packing cases lying about, and luckily they had not taken my matches.  I built a blaze and then, while it was still smoldering, I covered it with an old strip of sacking that I wetted with some water out of the bottle they left me.”