"There is a simpler mode than that," said I, "which geometry teaches us, and by which the highest mountains can be measured." I then showed the method of measuring heights by triangles and imaginary lines, using canes of different lengths and cords instead of mathematical instruments.

My result was thirty feet to the lowest branches.

This experiment filled the boys with wonder and desire to become acquainted with this useful, exact science, which, happily, I was able to teach them fully.
I now ordered Fritz to measure our strong cord, and the little ones to collect all the small string, and wind it.

I then took a strong bamboo and made a bow of it, and some arrows of the slender canes, filling them with wet sand to give them weight, and feathering them from the dead flamingo.

As soon as my work was completed, the boys crowded round me, all begging to try the bow and arrows.