This text is presented as a practical and simplified approach to vector electrocardiography. The introduction is clearly presented. The author has utilized a "motion picture" type of study of instantaneous changes in the vector loop. This technique is imaginative in approach, but fails in execution, because (1) the figures have been made too small, so that the pages must be scrutinized to find minute changes, and (2) although the idea of keeping the leads in spatial orientation is good, the reader must turn his head each time to get things right side up, thus losing the trend. This reviewer was unable to get a clear grasp of the patterns as presented. I think, however, that further work with this method of presentation may prove rewarding.