This is possibly an engineering, rather than physics, question. (Ooooooooo! Busted!) John picks up a paperclip and notices that it has been (very weakly) magnetized... it attracts other paperclips, but only at ridiculously short distances. John wishes to foster this interesting characteristic, but has no access to electricity or stronger magnets. How should he proceed to eventually make a strong bar magnet? I have no proof that such a thing is possible, but it seems to me that if I can rub a needle repeatedly with a magnet to organize the needle's molecules along an axis, without losing the original magnet's magnetism, then perhaps it is. My bet is that someone, hundreds of years ago, had the same thought and a lot more time to experiment, so I would guess it's a long-solved problem.