The lure, problems and promise of Siberia as a new frontier dominate this spare, factual outline which introduces in turn each successive wave of Siberian settlers -- the indigenous tribes like the Yakuts and Evenkis, ""old believers"" fleeing religious persecution, czarist political prisoners, and -- today -- Soviet workers drawn by special benefits and celebrated as ""heroes of labor."" Lengyel covers the usual geographical and historical background, conscientiously (though for more knowledgeable readers, redundantly) relating each development to the Russian scene as a whole. There is a tendency to bend over too far backwards in the interests of detente; post-1917 labor camps are granted only three sentences and the subject is closed with the observation that ""since not much has been heard about them in recent times, it is assumed that the treatment of prisoners has become less cruel."" Otherwise, functional and undemanding.