A Q-&-A grabbag, with a little something for everyone. Some of Barr's 538 numbered entries are simple riddles (the first transplant--Adam's rib); some matters of plain fact, well known (who said ""Let them eat cake""?) and otherwise (what 12 listed notables have in common is that they were all born in 1856); some involve arithmetic and geometry, logic or laws of physics (increasing the weight doesn't make the object fall faster). Ranging in level from kiddie fun (Q: What has three hands? A: A clock with an alarm or a second hand) to esoterica (HIUNDRATATATARIRE--an example of bagpipe music, as given by the verbal equivalents), the questions are packed tight, in a format that gives devotees more for their money but makes no visual overtures to the non-addict.