ON HAILSTONES, RAINDROPS, AND SNOWFLAKES. 161 



XX r. On the Formation of Hailstones y Raindrops, and 

 Snowflakes. By Prof, O. Reynolds, M.A., F.ll.S. 



Read November 13th, 1877. 



My present communication forms a continuation of the 

 paper I read before this Society on the 31st of October, 

 1876, " On the Manner in which Raindrops and Hailstones 

 are formed/^ 



To the contents of this paper I shall have to refer con- 

 tinually ; hence, in order to render what I have to say in- 

 telligible, it may be well for me to recapitulate some of the 

 leading points in my former paper. The chief purpose of 

 the paper was to explain the manner in which the minute 

 cloud-particles aggregated so as to form raindrops and 

 hailstones. 



Aygreyation resulting from the more rapid Descent of 

 the larger Particles. 



I commenced by pointing out that, as the suspended 

 particles of water or ice which constitute a cloud arc all 

 descending with velocities which increase with their size, 

 the larger particles will descend faster than the others, 

 and will consequently overtake those immmediately beneath 

 them ; with these they will combine so as to form still 

 larger particles, which will move with greater velocity and, 

 more quickly overtaking the particles in front of them, will 

 add to their size at an increasing rate. And I then pro- 

 ceeded to consider how far this was a sufficient as well as 

 a necessary cause of the phenomena of hail and rain. One 

 of the most important points on which my arguments were 

 based was 



SER. 111. VOL. VI. M. 



