Those not interested in the Machian view of dynamics should not be put off from buying this book. (It represents only a small part of the material while presumably voicing important philosophical issues.) The first half of the book focuses on the technical accomplishments of Hipparchus, Ptolemy, Copernicus and Kepler. Biographical detail is scant; the book articulates the technical advances, who made them and how they were made. Comprehensive explanations are accompanied by all the necessary illustrations. Some illustrations, being to scale, reinforce some of the challengers that beset the early astronomers. The step by step manner of progress laid down allows the reader to appreciate the ongoing achievements taking place. The book also covers the work of Huygens and Newton. I have not read these sections but feel that unlike many biographies of Newton the author delves more fully into the workings of Newton's mind as he developed his dynamical theories. No great mathematical knowledge is required to follow the thread. The book is well researched and Julian Balfour is a capable writer. Recommended.