You Must Be Joking To the Editor: Okay, it's about that lightning protection article, May '89. Sure it has some funny stuff in it. Like those positive charges that flash out to meet the negative charges--what are they? Electrons that hate their mothers? Heavy metal atoms on steroids? But it wasn't that funny, and it wasn't tongue-in-cheek, so I was trying to figure out what the story was. I think it's a false story you put in to see if everybody's b.s. detectors were tuned and operating. If you're giving away a free subscription to the first 100 letters or so, please note my address below. There was one cute paragraph about how ". . . only lightning currents of small