Page:Popular Science Monthly Volume 90.djvu/41

 The Wonderland of Ice Crystals

���Snowflakes and fragmentary crystals of nat- ural size. The size depends upon the tem- perature, the largest being formed when the thermometer stands just below the freezing. The star- shaped crystals are the largest

��At right: This deposit forms on window- panes in comparatively dry air and in both warm and cool rooms. Alt ough beautiful it is not so striking as the "window ice" which forms indoors in a thin film of water

��In the magnified stellar snow crystals below it will be noticed that the branches of the principal rays are parallel to the rays adja- cent. The crystals are more or less imper- fect but the types are nevertheless distinct

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