26 



Proceedings of the Royal Irish A cademy. 



From this table it would appear that the negative charge on sleet is very 

 similar in magnitude to tiie negative charge on rain ; but the positive charge 

 is much smaller thau the corresponding one. It is noteworthy that a decided 

 change in the form of precipitation is generally accompanied by a change in 

 the sign of the charge. 



Hail and Snoic. 



A good many showere of hail and snow were observed, especially in 

 March and April. The apparatus is not well suited for measuring the 

 charge on these forms of precipitation. It was possible, however, to measure 

 accurately the toul chai-ge on the snow and hail wliich fell into the appara- 

 tus, melt them afterwards with a known volume of warm wat«r, and thus 

 get the increase in volume of the water in c.cs. The following observations 

 were obtained in this way. 



Datr. 



Arerage charge' 

 Vol. ill e.c. per c.c. Sign of iharge. 



in E. S. U. 



Description. 



JUIUTT 4. 



66-0 



Mtrdi 



2<. 



22-5 



„ 



i*. 



9-0 



,, 



M. 



IK 



., 



27. 



371 



.. 



28, 



1130-0 



,, 



■i». 



9-0 



,. 



29. 



190-0 



., 



29. 



30-0 



,, 



SI. 



12SO-0 



.»pril 



1, 



216-0 



.. 



1. 



ITo-O 



„ 



'> 



110-0 



May 



3, 



150-0 



-382 



- 



Small hailstones. 



-156 



- 



.. 



218 



- 



• 1 ft 



1-09 



+ 



Large snov and hail (mixed) 



5-41 



+ 



Hail and large rain. 



■093 



- 



Snow. 



■J -06 



- 



Snow. 



1 -08.5 



+ 



Uail. 



118 



-^ 



Hail. 



2-47 



-^ 



Hail. 



6-18 



- 



Small faailflonu. 



6-18 



- 



Small faailflonu. 



f.-50 



1 ■ 



Uail. 



Snow and rain. 



lie 



1 



IlaU. 



■08' 



i 



- 



Small hailstones. 



The change from small hailstones to large hailstones is always very 

 abrupt when it occurs, and is always accompanied by an equally abrupt 

 change in the sign of the chaise. This is perhaps the most remarkable 

 characteristic of these showers. It provetl rather disconcerting at first, so 

 that for this reason, or owing to the use of too low a capacity, sevei-al 

 s'lowers wer« missed, or the charge not accurately determined and such 



