HE < )UTD( )( )\i \V< )RU>. 



435 



coatings to the true crystals. The 

 hulk oi the snow Fall, consisting of 



true transparent snow crystals, is 

 formed directly from the invisible 

 water vapor (individual water mole- 

 cules) in solution within the atmos- 

 phere and floating about among the 

 clouds, as well as below and above 

 them. In general the western quad- 

 rants only of widespread storms fur- 

 nish large quantities of perfect and 

 beautiful tabular snow crystals suit- 

 able For photographic purposes. As 

 a rule, the several cloud strata, the 

 low. intermediate and high, tend to 

 produce certain characteristic types 

 peculiar to themselves. The arrange- 

 ment of the air tubes and the shading 

 within the crystals, outlining various 

 geometrical forms, one outside the 

 other, shows more or less perfectly 

 the varied shapes that the crystals as- 

 sumed as development proceeded from 

 the center outward. Snow crystals, 

 differing but little or not at all from 

 those falling from storm clouds, some- 

 times form (though in small quantity) 

 and fall to earth from clear, cloud- 

 free air. Many types of snow have 

 their counterparts among frost and ice 

 crystals. Many of the irregularities of 

 form so characteristic of the crystals. 

 falling during thick and heavy snow 



storms are due to crowding; i. c to 

 the close proximity oi two or more 

 crystals while in the process of devel- 

 opment. Crystals that develop rapidly 

 tend to form in an open and arbores- 

 cent manner; those that develop slow- 

 ly become close and solid. 



Public recognition of my work came 

 slowly. \o illustrated or other kind of 

 articles treating of snow crystals ap- 

 peared until the "Popular Science 

 monthly" published an illustrated arti- 

 cle about them in 1898, twelve years 

 after the beginning of our studies and 

 photographic work. Many illustrated 

 articles treating of them have appeared 

 since then, both here and abroad. 

 These, and especially the writer's 

 "Studies of Snow Crystals during the 

 Winter of 1901-1902," one hundred and 

 fifty illustrations, published by r the 

 Weather Bureau have served to attract 

 world wide attention and admiration. 

 Recently the Weather Bureau has pub- 

 lished "Studies of Frost and Ice Crys- 

 tals," one hundred and seventy-five illus- 

 trations, and the writer hopes this latter 

 article, together with this little sketch of 

 our study, will help to call renewed 

 attention to the wonders and the 

 beauties of the crystals of frost, ice 

 and snow. 



SPECIMENS SHOWING "DAINTY" FINE LINES. 



