This neat, admirably written and beautifully produced little book is based on a series of sixteen lectures given to physics students at Imperial College by Professor Mason, from his newly created Chair of Cloud Physics in the University of London. His larger text (The physics of clouds, Oxford, Clarendon Press, 1957) epitomizes the results of the decade of active research to which his elegant experimental techniques have contributed so much, as those who know his papers will acknowledge.

In this concise introduction to the subject we begin with a summary of cloud forms and features. Nuclei of cloud condensation and growth of cloud droplets will attract many who want a summary of progress in recent years. Glaciologists will find the two chapters on the germination and growth of snow crystals, and on snow, rain and hail as precipitation especially interesting, although the emphasis is on events in the atmosphere. Nakaya’s work on crystal growth in this field has been extended by Mason and Hallett. Chapters follow on rainmaking experiments and on the electrification of thunderclouds.

Glaciologists who want a compact, up-to-date and readable account can be strongly recommended to this book. Physicists will welcome the descriptions of experimental techniques.The only criticism the reviewer would make is that readers will find it difficult to pick up many of the references, e.g. to Bowen’s work in Australia or “the work of the Cambridge school” (p. 118) as there is no full bibliography or list of papers, although a few sources are named in footnotes and captions. Otherwise, an excellent and delightfully compact account.