When the ice flowers or crystals first begin to appear, it is usually upon the surface of the water, and close to the sides of the pail. Frequently they push out in long, delicate, needle- or lance-like forms while upon the plain edges of these sharp lances, scallops and delicate serrations quickly follow. But the individual or flower type of crystals which grow and scatter themselves over the surface of the water, do not attach themselves to any object, but grow in a detached fashion, and are really the most interesting crystal for observation and study. These detached crystals following out the laws which govern also the frost and snow crystals from their first stage of development, form a simple, smooth-edged disc of very thin transparent ice, gradually merging into the same, hexagonal, flower-like pattern, which governs the frost and snow crystals, although during the first stages of their development they show no tendency to follow hexagonal outlines. The photographed illustrations showing this type of ice crystal, from its start to finish were most of them taken from indoor observation.
118. High altitude crystal with germs attached
119. A daintily etched centre design
Beginning with photograph [No. 128], we have the germ or birth, showing the first stage which the ice crystal assumes in its formation. It is always seen as a round disc of very clear, thin ice.
[No. 129] illustrates the second stage of growth in which the tiny serrations or scallops are just beginning to shoot out and form about the germ or disc. Frequently they remain in this stage of development for some time without further change, but when it is zero weather they quickly increase in growth, and soon begin to show clearly defined scallops as shown in photograph [No. 130].
In [No. 131], the ice crystal has at last begun to assume definite form, and its hexagonal shape is more clearly defined; while in [No. 132], we have the completed flower-like outline, and in Nos. [133] and [134] the finished ice flower with its air inclusions of light and shade perfected. This shows the entire process of growth of the commonest type of these ice crystals, after which process they lose their identity and merge into the solid ice film.
However, ice film growth is not wholly supported in this manner, for branches often form upon the under side of the ice film, and grow downward into the water, as shown in photograph [No. 135], which is a section of ice with fern-like crystal-growth growing down into the water, thus aiding in growth and solidification. Each type of crystal, and there are five, represents some different characteristic growth—the long, narrow, needle type, the simple stars of six points, and the spherical or discoidal forms; also those resembling coral-like formations.
