June 22, 1888.] 



SCIENTIFIC NEWS. 



58X 



REMARKABLE HAILSTONES.— II. 



{Concluded from p. 558.) 

 A S a rule it was found, in tliese crystalline hailstones, 

 •^"^ that the growth and prolongation of the crystals 

 had taken place in a plane, corresponding to the direction 

 of the longitudinal axis of the spheroidal nucleus, as 

 may be seen in the figures. However, this rule 

 is not free from exceptions, since it often occurred 

 that ice-crystals, independently developed, had attached 

 themselves to the flattened sides of the spheroid, 

 and appeared to be sometimes deeply rooted in the 

 interior mass of amorphous ice. In making sections 

 of the hailstones, and on breaking them, it was plain that 

 the crystals, when removed, often left behind them an 



Fig, 3. 



angular depression corresponding in shape to their lower 

 extremity, something like the relation of a tooth to its 

 socket. This was especially the case in stones which, 

 like those of figs i and 2 (Scientific News, p. 557), were 

 covered with crystals of unusual size. 



The spheroids were thus in the majority of cases 

 encircled with garlands of parasitic crystals, a phenomenon 

 which seems closely connected with the causes which 

 determined the lateral flattening of each entire mass. 

 Even the extreme disc-like forms show this connection 

 quite distinctly. Fig. i gives a representation of the 

 normal relations between the length and the thickness 



of these ice-masses, garnished, as will be seen, with a 

 dense series of rhombohedric crystals, some of them as 

 much as 2 inches in length. There were also a few 

 specimens of very indefinite shapes which seemed as if 

 formed by the reunion of half-melted masses. Fig. 3 

 shows a mixture of sharply-defined crystals and of 

 masses partially melted. But the texture and the poro- 

 sity of the most irregular masses showed a nearer 

 approach to the primary spheroidal nucleus than to the 

 secondary parasitic crystals. The ice of these varieties 

 displayed in general the blueish colour of glaciers. 



From a comparison of the dimensions of the hailstones 

 represented in figs, i to 4, the maximum length was 

 4 inches by 2| inches in thickness. The weights of the 



Fig. 4. 

 largest stones, as determined by the observer, ranged 

 from 3i to 4 ozs. The ice melted remarkably slowly at 

 the atmospheric temperature of 62" Falir, 



The next morning it was observed, after remo\-al of 

 the water, that the ice in the iron vessel in which the 

 hailstones had been collected, consisted chiefly of veiy 

 regular convex lenses, 10 to 12 millimetres in breadth, 

 and 5 to 6 millimetres in thickness. These lenses were, 

 to a great extent, freed from bubbles and chinks, and 

 were as clear as ordinary magnifying glasses. The 

 nucleus of the original spheroid was either quiie clear 

 or still slightly opalescent. There remained no trace of the 

 radial, spoke-like lines springing from the central nucleus. 



The water which remained on melting the hailstones 

 left, on evaporation, no trace of solid matters, even on 

 examination with a strong magnifying power. 



A similar hailstorm is recorded as having taken place 

 at Marienfeld, to the east of Tiflis, on September 12th, 

 1863. The spherical hailstones, however, were covered 

 merely with needles and teeth of ice, and not by any 

 means with regularly developed crystals. 



The observer, Herr Abich, makes no attempt to 

 account for the remarkable and, as we believe, very 

 exceptional phenomena which he describes. 



