A glossary of the most important terms used in geology (except for mineralogy and paleontology) in 1955. The definitions are unusually complete and many include discussions of usage, in some cases attributed to sources.
The completeness of the definitions made this book very useful to me as a grad student in the 1980s. For example, "alluvial fan" is described in a full paragraph rather than the single brief phrase that it would get in most dictionaries. However, its use today will be limited by the absence of words originating after 1955, including the terminology of plate tectonics and sequence stratigraphy, to mention only two fields. Nevertheless, the glossary will remain a useful source to historians of geology.