Each one of the thousands of moving pictures, as I have explained in previous books, is three-quarters of an inch deep, though, of course, on the screen it is enormously enlarged.
After the film has been exposed, three-quarters of an inch at a time, it goes below into another light-tight box of the camera, whence it is removed to be developed and printed. The movement of the film, the operation of the claws and the opening and closing of the shutter, making it possible to take sixteen pictures a second, was, in this camera, all controlled by the air motor.
Joe and Blake found much to amuse them in San Francisco, which they had never before visited. They were a bit “green,” but after their experiences in New York they had no trouble in finding their way around.
“We’d better go to some hotel, or boarding house,” suggested Joe, after their arrival. “Pick out one where we can leave the camera working while we’re gone.”
They did this, being fortunate enough to secure rooms in a good, though not expensive, hotel near the financial district. One of their windows looked directly out on a busy scene.
“That’ll be just the place, and the sort of scene Mr. Ringold wants,” declared Blake. “Let’s set the camera there on the sill and see what it gets. The light is good to-day.”
It was, the sun shining brightly, and being directly back of the camera, which would insure the proper illumination.
They adjusted the machine, and set the mechanism to go off about an hour after they had left the room. Then they went to find the shipping agent, to see if they could get any news of Joe’s father.
But, to their disappointment, he was out, and none of the clerks could tell them what they wanted to know. They were directed to return the next day.
“More disappointment!” exclaimed Joe. “It does seem as if I was up against it, Blake.”