CHAPTER IV
"DANGER—COME"
IT was anxious work, standing around while Hank ran the film from his camera through some kind of machine which he had, to bring out the picture. After what seemed like a long time he took it out and looked through it toward the light.
"Hurrah!" he yelled. "We've got 'em."
We all crowded around to look, and sure enough at one end of the film we could see as plain as day two men standing up and looking toward us. And there was the brook, too, and the ravine, so real that we almost could hear the water pouring over the stones, which we think is the sweetest music in the whole world. Away back in the picture was the bush, behind which we boys were hiding when Hank took it. Only you couldn't see us at all, for we had been careful to keep out of sight.
It is wonderful, isn't it? I don't know how it is done and I don't believe that anybody else knows, but I know that it is so because I saw it with my own eyes.
Hank washed the film, and after it was dry put it in a frame with some paper which he had, and held it up to the gas jet. In a few seconds the picture showed up on the paper fine, just like our writing does when we do it in invisible ink and hold it up to a blaze.
We could tell who it was, all right. The big one had a scowl on his face, as if he had put it there when Hank tossed the stone and hadn't had time to smooth it out again.
"This picture is for the marshal," Hank told us. "Now I'll print another for the patrol. We'll let them soak and wash a while, and then dry them out. It'll take quite a long time, but we've got 'em all right."