An accurate portrayal of the events leading up to and following the momentous discovery, this forsakes the too-easy suggestion of serendipity for a more complete and accurate discussion of the complex interplay of men and events that culminated in the recognition of X-radiation. In so doing, Mr. Dibner does not find it necessary to be mechanically and tediously chronological. In the case of Roentgen especially, this would be a disservice to the reader, for here we have one of the last generation of physicists able to become physically as well as mentally involved in his discovery. Picture Roentgen, having discovered this penetrating radiation, running about his lab picking up any object--wooden, metal, glass, whatever--in order to place it in front of the new ray to see if it will be penetrated. The author also shows the public furor which the new discovery caused, including some of the absurd claims made by others for it. An appendix contains a translation of the original Roentgen announcement. This is one of the better historical biographies of a scientist for young people; so, however, is the Esterer, below.