How do you know that no two snowflakes are exactly alike? Does it matter? For the scientist, the similarities between snowflakes are just an interesting, and probably much more important, than their differences. The author of the text in "The Snowflake" is Chairman of the Physics Department at Caltech. While he is involved in gravitational wave experiments and the development of tunable lasers for physics education, he also makes time to study snowflakes. With his photography collaborator Patricia Rassmussen, he has put together a beautiful book that intices the reader to join the fun of snowflake photography. The author's Web site, www.snowcrystals.com, not only explains how he grows "custom" snow crystals, but also how you can make your own pictures like his. These authors follow in the footsteps of the genius Wilson Bentley, who was first to photograph a single snowflake in 1865, and whose amazing pictures Snow Crystals are still in print from Dover Publications (I bought my copy "some time ago". The price on the cover is $3.25).