S84< M. De la Rive on the Formation of Hail. 



polished stones which formed part of the cornice of houses were 

 broken on their edges, and some phonolite slabs, which were em- 

 ployed instead of the tiles which cover the roofs, were broken by 

 the shock of the masses of ice. Finally, a considerable part of 

 the beautifully stained glass in the windows of the Cathedral of 

 Clermont was in a few minutes broken, although it had been ex- 

 posed for at least four centuries without having been injured by 

 any storm. 



The hailstones fell very obliquely, so much so, that many 

 persons were struck by them in their rooms, after they had 

 entered through their windows ; others were surprised in the 

 fields and were wounded, though I have not heard that any were 

 killed. I anticipated that I should have discovered a marked ro- 

 tatory motion in the hailstones, but I could not convince myself 

 of it at the moment of their fall, for they almost all broke instant- 

 ly on the pavement. 



The fall of the hail was scarcely over when I went, accompa- 

 nied by M. Bouillet into the Botanic Garden, with the intention 

 of examining the hailstones. Here we found many which, from 

 having fallen upon the plants, were quite entire, and presented 

 very remarkable forms. Their medium size was about the size 

 of a pullet's egg, and some were as large as a turkey's. We 

 were, however, informed that some of larger dimensions had 

 fallen at Montferrand. Their form was an elongated spheroid, 

 with the two extremities apparently equal : they were gene- 

 rally studded over with crystals, some of which still bore the 

 shape of hexagonal prisms, terminated by six-sided prisms ; but 

 more frequently the angles had melted away, and the prisms had 

 become cylindrical. Some of these superadded crystals projected 

 as much as eighteen lines at the moment of their fall, and some 

 according to appearance were two inches high. Other hailstones 

 were only rough on their surface, and presented an infinite num- 

 ber of small elevations, like the masses of sulphuretted iron which 

 are found in certain clays and lignites. 



The crystals were grouped at the two extremities of the 

 great axis of the ellipsoid, which, to all appearance, were the 

 two poles of the hailstones, and their equator, so to speak, was 

 deprived of a large proportion of them : in all the crystals were 

 largest at the two extremities. The interior structure of the 



