"I wish I had a straight stick, and then we could tell exactly," remarked Alfred, as he looked around for something to verify the assertion.
"Use a string," said Ralph. "Here is one; wait, and let me stand right over the stone. Now, I'm going to stretch it and hold it parallel with the arrow below. When I give the word sight along the string and see whether or not it crosses the hill in the distance."
"All right," answered Alfred. "Lower the right hand a little; it over-shoots the hill too much; are you ready?"
"Yes; how is it?" asked Ralph.
"Oh, it points down to the hollow left of the hill," said Alfred, "so I suppose the mark must be intended for something else."
"Come on, Frisky; enough of that," shouted Alfred. "Up the hill," and he marched off whistling.
After Ralph started Frisky jumped out of the hole, gave a few discouraging barks, and leaped after the boys.
Within fifteen minutes the motor camp was reached; then great cave-like holes were noticed, stored with huge shells, and numerous smaller caves, in which were men lying about.
"There the guns are," said Alfred. "Well, they have them nicely hidden, and I don't see how the flyers would ever pick them out the way they are arranged."