mething," insisted Blake. "You hear
Alcando and someone else talking about a machine, and you at once
jump to the conclusion that it's a camera."

"No, I don't!" exclaimed Joe. He did not continue the conversation
along that line, but he was doing some hard thinking.

Later that evening, when Mr. Alcando called at the room of the two
chums to bid them goodnight, he made no mention of his visitor on
the balcony. Nor did Blake or Joe question him.

"And we start up the Canal in the morning?" asked the Spaniard.

"Yes, and we'll make the first pictures going through the Gatun
locks," decided Blake.

"Good! I am anxious to try my hand!" said their "pupil."

With their baggage, valises, trunks, cameras, boxes of undeveloped
film, other boxes to hold the exposed reels of sensitive
celluloid, and many other things, the moving picture boys and Mr.
Alcando went aboard the government tug _Nama_ the next morning.
With the exception of some Army engineers making a trip of
inspection, they were the only passengers.

"Well, are you all ready, boys?" asked the captain, for he had
been instructed by his superiors to show every courtesy and
attention to our heroes. In a sense they were working for Uncle
Sam.

"All ready," answered Blake.

"Then we'll start," was the reply. "I guess--"

"Oh, one moment, I beg of you!" cried Mr. Alcando. "I see a friend
coming with a message to me," and he pointed along the pier, where
the tug was tied. Coming on the run was a man who bore every
appearance of being a Spaniard.

"You are late," complained Mr. Alcando, as the runner handed him a
letter. "You almost delayed my good friend, the captain of this
tug."

"I could not help it," was the answer. "I did not receive it
myself until a few minutes ago. It came by cable. So you are off?"

"We are off!" answered Mr. Alcando.

Then the other spoke in Spanish, and later on Blake, who undertook
the study of that language so as to make himself understood in a
few simple phrases knew what it was that the two men said. For
the runner asked:

"You will not fail us?"

"I will not fail--if I have to sacrifice myself," was the answer
of Mr. Alcando, and then with a wave of his hand the other went
back up the pier.

"All right?" again asked Captain Watson.

"All right, my dear sir, I am sorry to have delayed you," answered
Mr. Alcando with more than his usual politeness.

"A little delay doesn't matter. I am at your service," the
commande