The next thing was to run the main string down and under one of the sapling supports on the brush screen where the camera was concealed. He smoothed away the bark from the wood so that the string would slip easily, and then ran it back up to the ridge of the lean-to. From there it was brought across and down to the ground, where the trap was to be laid.
“You see the idea, now, don’t you?” Dick asked.
“Well, we have vague glimmerings, and that is all,” answered Garry, speaking for himself and Phil.
“The thing is simple enough. This cord has been brought around so that it is attached to the lever and to this trap. When someone steps on the trap, it will sink just enough to pull on the cord, and that will bring down the lever, and presto, your picture is taken.”
“Well, I see that,” said Garry, “but what’s to prevent its taking another picture when someone steps on it again?”
“Easy again. Once the camera has been snapped by the trap, its work is done. You see the lever on this camera takes one picture when you pull down, then to get another, you push the lever back up. Of course there is nothing in this crude trap that will push up, so you can take only one picture without resetting the trap,” explained Dick.
“That’s well explained; now tell me something else and I will keep quiet for a while,” said Garry. “Why have you tied some extra threads to your main line that leads to the lever?”
“That’s an extra precaution. If I had a wide board that I could set in the ground, a weight on any portion of it would cause the entire board to sink a bit, and that would give the necessary pull to release the lever. But we have no board and so I must lay these strips of sapling close together. Suppose that the intruder steps on one spot, he would only cover about nine or ten of these saplings, and if my string was not hitched to those particular saplings, the trap wouldn’t work. The idea of the extra strings is so that on whatever portion of saplings anyone stands, he will be sure to pull down on a string. Savvy?”
“Right, as usual, I stand corrected,” murmured Garry in a purposely humble tone.
Dick looked at him sharply.