their richness in beautiful snowflakes. A favorable winter may furnish as many as fifteen good snowfalls and 300 or more new photos.
Good snowfalls often occur during, or at the end of, a period of zero weather. Great storms and blizzards not seldom give opportunity of gathering wonderful crystals. Yet, as a rule, less intense snows, when the crystals are of but medium to small size and fall rather scatteringly, are most favorable.
Three Examples of the Perfect Symmetry of Snow Crystals; They Probably Are Built Up Layer by Layer from the Center, Until All the Branches and Petals Are in Place
The larger flakes rarely exceed one-third inch in diameter. Often the best ones are tiny bits of pure beauty from one-twentieth to one-fiftieth inch in diameter. The percentage of perfect crystals in a favorable snowfall varies greatly. Sometimes all will be so rarely beautiful as to make selection a bewildering task, while again one may search all day long to find one or two perfect ones.
Snow crystals are never formed as a result of the freezing of raindrops or of visible clouds. Hail and granular snow result thereby. The making of the true snow crystals is far more complex. Each cloud-born jewel is the product of a process that goes on in one of the rarest laboratories in the universe, the thin air in which we live, and through the assembling of the unseen atoms and molecules of which all crystals are built.
The snowflake is doubtless built by stages from its center outward. And as it grows, and its branches and other adornments unite, it bridges over and imprisons tiny quantities of air, in the form of minute tubes. These look dark when viewed visually or photographed, and, together with other dark features, due to abrupt changes in thickness, give great richness of design to their interiors, and serve to outline the various transitory forms the crystals assumed in cloudland. They assume most varied forms, resembling dots and dashes, lines and other strange characters. Frequently they are arranged in a wonderfully symmetrical manner. The number of divisions a crystal may assume, whether it be a snow or other crystal, is supposed to be determined by the number and arrangement of the atoms that group together to form it.
The tiny magnetic poles of these crystals attract other atoms to them and establish lines of growth, called axes, and the bodies grow mainly outward from them. Minor variations in form depend upon the number and arrangement of the tiny electric charges that collect upon them and establish secondary or third-degree axes, and upon their rates of growth and the temperature. Rapid rates of growth tend to produce open branching crystals; slow rates of growth, solid ones. In the case of snow crystals, the branchy ones usually form within the lower, warmer, wetter clouds, because there is more material there for rapid growth, while the more solid ones form at higher, colder, drier altitudes. Not seldom they are wafted upward and downward within the clouds, and have both of these characteristics of growth impressed upon them.
Exceptionally beautiful crystals, when photographed, are used by schools, museums, lecturers, art-craftsmen, silk manufacturers, metal workers, interior decorators and other designers.
