Beginning well before the time and the place where the river meets the road, Mr. Billings explores American bridges and bridge building with an imagination that makes his interpretation of the subject singular. There is clarity of organization too. His discussion of the modern bridge building era is preceded by geological reference to the structure of the land, by what we know of ancient bridges and ducts, and by the tie between bridges and our growing traffic problem. From this we move to bridge history and types, told through descriptions of 19th century wagon bridges, the stone arc and metal truss, the revolutionizing steel structures, and, with this, special mention of built and unbuilt bridges in congested areas today. Much has been written on the subject, but there is a new fascination and completeness in this survey.