A scholarly, well-researched environmental history of the Rhine, particularly its role in European economic and national history over the last 200 years. Cioc, who documents the profound ecological degradation of the overburdened river, also devotes a chapter to hopeful signs of restoration. He does a good job of telling the story of the Rhine and the consequences of tinkering by hydrologists and engineers. Though the river flows through the heart of industrialized central Europe, it's less than 1,000 miles in length and now without much of the riverine vegetation and floodplains that once helped to keep it clean.  (GER130, $24.95)