just as a side note,you don't see as much info in the camping "how too do it" books on the ax and it's care and sharping as you once did.i have some older books that have not only the use of the hockey puck shaped stone but how to drive in stakes to hold the ax against a log so you can file with both hands,more control i guess. and some more detailed stuff on how to bury the head in such a way that a busted handle can be burned out without killing the temper of the edge.
I am always looking for old camping and hiking books. There is so much lore that has been nearly lost. That is why I admire guys like you who go to nature centers and give kids a taste of the past. Oddly enough, most of the old timers that I have read advise against hatchets in favor of a full sized axe. Some go as far as to say a full sized axe is the only indepensible survival tool that there is. They say that a hatchet is too small to be effective and dangerous to handle. One example is the 1971 book 'Backcountry Camping' by Bill Riviere. He has a chapter on backwoodsmans tools that really explores the axe. This guy looks exactly like I always thought a '50s backwoodsman should look. Floppy hat, boots, pipe, and a checkered flannel shirt. He lived the backwoods life that I wish I could live.