Siegfried has done a more scholarly and penetrating job this time than he did in his disappointingly superficial Canada. And he has chosen a subject that is teeming with interest for every student of world affairs today. The two Canals are ""in the news"" as has not been the case since their first amazing emergence. They are vital lifelines to international existence. Siegfried has searched into their history, their geography, the personalities that brought them into being, their importance in world traffic and world commerce. Implicit throughout is the problem of the Canals in the present conflict -- proving grounds for armies, navies and air forces of the world.