"You also know that all three of us have been practicing at telegraphy a
good deal during the past few weeks, because every man who follows the
sea ought to know how to send and receive wireless messages at need."

"Yes; I know that, Benson."

"Well, sir, I guess that the lead has been hitting the top of the
'Farmun's' hull, and I've been tapping out the signal--"

"The signal, 'Come up--rush!'" broke in Hal, with an odd smile.

"Right-o," nodded Jack Benson.

"How on earth did you know what the signal was, Hastings?" demanded
Mr. Farnum.

"Why, sir, I've been sitting so that I could see Jack's arm. I've been
reading, from the motions of his right arm, the dots and dashes of the
Morse telegraph alphabet."

"You youngsters certainly get me, for the things you think of," laughed
the shipyard's owner.

"And the 'Farnum,' or whatever it is, is coming up," called Captain Jack,
suddenly. "I just felt my lead slide down over the top of her hull.
Hard-a-starboard, Hal, and row hard," shouted young Benson, breathlessly.

Though Hastings obeyed immediately he was barely an instant too soon.
To his dismay, Mr. Farnum saw something dark, unwieldly, rising through
the water. It appeared to be coming up fairly under the stern of the