ROUND THE YEAR 



affect the regularity of the crystalline masses, and the 

 freaks of hoar-frost are many. 



Many snow-crystals exhibit under the microscope 



FIG. 8. Natural hoar-frost, Christmas, 1892 ( n,f, natural size, the rest enlarged). 

 From Grossmann and Lomas, Nature, Oct. 18, 1894. 



cavities containing air, or water, or both. These 

 cavities are sometimes of very regular form, spheres, 

 or elongated tubes pointed at each end. In other 

 cases three sides of the hexagon exhibit one 

 pattern (a. Fig. 9) and alternate with three sides of 

 different pattern (.)'. The similar crystals of hoar- 

 frost have never been found to contain such cavities. 



