530 



[Oct. 18, 



1, 1889, presented some peculiarities wliicli the autlior desires to place on 

 record. 



The storm was heralded by the usual bands of dark clouds and a high 

 wind velocity. A fall of rain was followed by a copious fall of hail. The 

 storm was of short duration and was rapidly followed by a clear sk3^ 



An examination of a number of hail stones which fell on a grass plot 

 in the northern section of the city showed the following peculiarities, viz. : 



(1) Most of the larger stones examined were nearly spherical in shape, 

 with only a slight tendency to an oblately spheroidal shape. Some of 

 them varied in diameter from an inch to an inch and a quarter. 



(2) The smaller stones were, on the contrary, so markedly oblately 

 spheroidal as to closely approach in many instances the shape of flat discs. 



(3) Cross sections of the stones showed the usual concentric layers of 

 alternate opaque and transparent ice. 



(4) The nucleus of the stones examined was of opaque ice. 



(5) The outer layer of nearly all the stones, and, without exception of 

 all the larger stones, was of opaque ice. 



These peculiarities are common to nearly all hail stones, and are only 

 referred to in connection with a peculiarity I have never before noticed 

 in hail stones, nor have I ever seen the same referred to in the literature 

 of the subject. 



On the outer surface of a number of the larger stones examined, well- 

 marked crystals of clear transparent ice projected in some instances for a 

 full quarter of an inch. These crystals, as well as I could determine from 

 the perishable nature of the material, were six-sided prisms with clearly 

 cut facets, and well-marked terminal faces. The crystals projected from 

 the surface of the stone in the direction of their greatest length. They 

 closely resembled the crystals so common in geodes Avhere the mineral 

 matters are slowly deposited from the mother liquor. 



The size and transparency of the crystals, and the well-defined charac- 

 ter of their edges and faces, indicated their formation under conditions 

 favorable to crystalline growth, among the most essential of v, hich are 

 time, and comparative freedom from motion during formation. 



It would appear, therefore, that the stones must have been in a condi- 

 tion of actual or comparative rest in a mass of vapor-saturated air for a 

 short interval of time after their formation, and immediately before their 

 fall to the earth. 



The conditions of rapid motion so usually assumed in the generally 

 accepted theories for the formation of hail are so opposed to such a rest of 

 the hail stones, that the condition of rest in the stones appears to be improba- 

 ble, unless such theories be considerably modified. 



It has been suggested, however, that an actual rapid motion of the 

 stone, while surrounded by an accompanying mass of vapor-laden air, 

 would place the stone in a position of relative rest as regards the aii', and 

 so give the crystals the opportunity required for growth. 



Whatever meteorological conditions may have existed during the forma- 



