"When we make drawings of the shapes of the leaves that will take us along another step, and thus enable us to find out just what kind of tree or plant we are talking about."
Fig. 16. Dentate. Fig. 17. Crenate.
The following day Harry proposed a trip over to the cave which George had discovered at the time he found the big air pocket that shot water and spray out into the ocean.
"I am interested," he said, "in seeing the air pocket George spoke about, and we might as well take our vacation to-day."
"As the distance is not great we need not bother about taking our luncheon along." And off they started, with the Professor bringing up the rear.
The course was first to Observation Hill, where they had erected a new and a larger pole than the one which had so mysteriously disappeared two months before. On every such visit it was the duty of the one who made the trip to scan the horizon in every direction.