Yeomans provides a history of cometary thought—both scientific and superstitious—from the ancient Greeks and Chinese right up to the present. In his last three chapters he discards this straightforward chronological organization for a thematic one, combining the history of twentieth century research with a summation of the current state of knowledge. One of these chapters details studies of Comet Halley.

"Myth and folklore” are terms used by Yeomans to describe the beliefs that comets are portents of events, generally unhappy events. He is frequently critical of past thinkers who did not see the division between natural and supernatural in the same way he does. However, his criteria for inclusion was the influence of ideas on contemporary and later thinkers, not whether the ideas were correct or rational in the eyes of modern astronomers.

In both style and structure, this book more closely resembles a text than a narrative history, although the tedium is occasionally relieved by sidebars which highlight the colorful personalities who have been interested in comets.

The stylistic limitations should not bother most readers, who will probably use COMETS as a reference work. It is excellent for this purpose. It has an outstanding bibliography and a useful index. Each chapter contains an abstract and a summary. The book is accurate, logically organized, and well-illustrated.