Cragoe makes no assumptions about her readers' knowledge of architecture, yet has managed to provide a surprisingly informative yet concise volume.
She begins by illustrating the features which which help us to identify the function and style of buildings and the construction materials. However, most of the volume is devoted to the features (the towers, windows, domes etc) which provide 'clues' to the period and place. Short yet informative paragraphs complement the engravings, which are painstakingly detailed, despite being small.
Much (possibly most) of this volume is devoted to examples which follow classical and church architecture. There are some references to vernacular houses, shops etc, but they are covered in less detail. Nevertheless, this is an exceptional valuable resource, both for those who are involved in the design process, and for lay readers.