Wiesenthal, head of the Vienna-based Documentation Center, who has made a career of finding fleeing Nazi criminals (Eichmann, among others), has set out with equal doggedness to track down Columbus' ethnic origins. There are ambiguous signs -- Columbus was too erudite to have been a simple weaver, he quoted Old Testament scriptures, used an arcane cipher in letters to his son, spoke Castilian too well to have come from Genoa -- that the explorer might have been at least part Jewish. But was he a Spanish Marrano, or from a Jewish family which migrated from Cologne to Italy? Because his first voyage was unmistakably financed by two court Marranos, did he set off expecting ""to be reaching countries in which Jews lived and governed?"" (His official interpreter spoke Hebrew.) And was he not, at the end, inadvertently successful in carrying out his ""secret mission"" because the Caribbean Indians were descendants of the Ten Lost Tribes of Israel? Wiesenthal is too methodical a scholar to leap to conclusions; he limits himself to suggesting these hypotheses and marshaling the evidence in the framework of Spanish court politics, the Inquisition and the expulsion of the Jews from the Iberian Peninsula. Unfortunately the questions raised are highly academic, of interest only to Judaicists, Hebraicists, and those intrigued by similar conundrums such as who wrote Shakespeare's sonnets -- or whether Ericson got here first.