"Oh, nonsense!" interrupted Blake. "Don't imagine too much. You think that curious box is some attachment for a moving picture camera; do you?"
"Well, it might be, and—"
"And you're afraid he will get ahead of you in your invention of a focus tube; aren't you?" continued Blake, not giving his companion a chance to finish what he started to say. For Joe had recently happened to hit on a new idea of a focusing tube for a moving picture camera, and had applied for a patent on it. But there was some complication and his papers had not yet been granted. He was in fear lest someone would be granted a similar patent before he received his.
"Oh, I don't know as I'm afraid of that," Joe answered slowly.
"Well, it must be that—or something," 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."