"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 commander said. "Well, now we'll start."
If either Blake or Joe felt any surprise over the hurried visit, at the last minute, of Mr. Alcando's friend, they said nothing to each other about it. Besides, they had other matters to think of just then, since now their real moving picture work was about to begin.
In a short time they were moving away from the pier, up the harbor and toward the wonderful locks and dam that form the amazing features (aside from the Culebra Cut) of the great Canal.
"Better get our cameras ready; hadn't we, Blake?" suggested Joe.
"I think so," agreed his chum. "Now, Mr. Alcando, if you want to pick up any points, you can watch us. A little later we'll let you grind the crank yourself."
I might explain, briefly, that moving pictures are taken not by pressing a switch, or a rubber bulb, such as that which works a camera shutter, but by the continuous action of a crank, or handle, attached to the camera. Pressing a bulb does well enough for taking a single picture, but when a series, on a long celluloid strip, are needed, as in the case for the "movies," an entirely different arrangement becomes absolutely necessary.
The sensitive celluloid film must move continuously, in a somewhat jerky fashion, inside the dark light-tight camera, and behind the lens. As each picture, showing some particular motion, is taken, the film halts for the briefest space of time, and then goes on, to be wound up in the box, and a new portion brought before the lens for exposure.