I kind of fell in love with saps and jacks a while back. From a hopelessly nerdy desire to produce a history on something no one ever has, I now have a manuscript I'm shopping around but good grief that's a long, slow process.
I obviously find them fascinating... used by Teddy Roosevelt, Al Capone, Jack Ruby and of course generations of police, sailors and even soldiers.
Legalities aside (for now), I think they occupy a unique space that has never been filled since they fell away. Something no longer than the length from my outstretched pinky to thumb, weighing less than a pound that can break bones (jack) or produce a KO (sap) with nothing but wrist action (in practiced hands)? That's kind of amazing.
I have an (amateurish) overview and collection vid if anyone's interested...
Didn't come here to self-promote, it's just that I almost fell out of my chair when I stumbled across this thread today.