An unusual book of ""mystery"" photos (black-and-white) with little in the way of verbal description. They are grouped into sections according to some theme (i.e., Snow on the Road, Snow on Roofs); each picture is captioned by the mystery question, Who made these tracks? Answers follow each section. A small selection of snow activities is added which includes interesting and hard-to-find information on various physical forms of snowflakes. But the photographs (familiar to readers of Nature and Science Magazine) constitute the major portion of the book; they are sometimes entertaining, sometimes instructive as science, sometimes poorly resolved (in this book), sometimes cute without making any positive contribution. One thing is certain--there is not much on library shelves which is comparable.