184 On the Theory of Rail. 



was f in. long, and J in. in diameter. All the perfect stones 

 (except those of clear ice) had a distinctly fibrous structure, 

 and were more or less pear-shaped, unless broken in their fall. 

 Some showed only two broad bands, others as many as five 

 or six. 



Figs. 15 and 16 represent two different forms of hailstone, 

 which fell during a violent storm in Cambridgeshire, on 

 August 9th, 1843. Some of the stones were so large that 

 they stuck in a wine-glass 36 . 



Fig. 17 represents a hailstone that fell in Georgia on May 

 27th, 1869. It was picked up, together with others like it, 

 and drawn at the time by Staatsrath Abich, and described by 

 him in a letter to Chevalier W. von Haidinger 37 . Similar 

 stones also fell on June 9th at 6 p.m. They were 2 \ in. 

 in diameter, spheroidal, of definite crystalline structure, over- 

 grown along the plane of the major axis by a series of clear 

 crystals, exhibiting various combinations belonging to the 

 hexagonal system. The most abundant were combinations 

 of the scalenohedron with rhombohedral faces, crystals f in. 

 in height, and corresponding thickness, prettily grouped, with 

 combinations of the prism and obtuse rhombohedron. The 

 terminal plane was also occasionally noticeable. Some which 

 fell at the beginning of the storm were flat tabular crystalline 

 masses 1-J in. in diameter. The ring surrounding the nucleus 

 had a milky appearance from the presence of small air-bubbles, 

 as had the nucleus itself in most instances : many had also a 

 clear nucleus. In melting down, some of the stones took the 

 shape of a regular hexagon. The milky ring round the 

 central point was a sort of fibrous web, composed of the 

 finest air-cavities, traversed by thread-like pores. Some of 

 the air-bubbles were pear-shaped or worm-like, running from 

 centre to circumference. The crystals were attached para- 

 sitically to the edge of the stone, or else inserted in a kind 

 of socket, as was noticed when the stones thawed down. 



Highgate, N., July 1889. 



36 Observations in Meteorology, by the Rev. R. Jenyns, M.A., F.L.S. 



37 Journal of the Austrian Meteorological Society, iv. p. 417, translated 

 into the Annual Report of the Board of Regents of the Smithsonian 

 Institution for 1869. Professor Henry was kind enough to send me a 

 copy of this work. 



