As this book is written for boys of all ages, it has been divided under two general heads, "The Tomahawk Camps" and "The Axe Camps," that is, camps which may be built with no tool but a hatchet, and camps that will need the aid of an axe. The smallest boys can build some of the simple shelters and the older boys can build the more difficult ones. The reader may, if he likes, begin with the first of the book, build his way through it, and graduate by building the log houses; in doing this he will be closely following the history of the human race, because ever since our arboreal ancestors with prehensile toes scampered among the branches of the pre-glacial forests and built nestlike shelters in the trees, men have made themselves shacks for a temporary refuge.