RAIN AND SNOW 



93 



consequently the size of the drop, we may be- 

 lieve when we consider how small are the rain- 

 drops in winter and how large they are in 

 summer. The first ones falling in a thunder- 

 shower, for instance, are unusually large. Pos- 

 sibly the size is caused by the outer edge of a 

 heavily saturated cloud being driven by the 

 wind against cold air and swift condensation 

 following the meeting ; or it may be that the 

 heavy drops fall from a very high cloud and 

 coalesce with others in falling. It is usually 

 only the first-coming clouds that cast the heavy 

 drops, and after the first dash they grow finer, 

 smaller, and more numerous. 



A thunder-storm comes and goes quickly, 

 the moisture being in measure localized. Both 

 its coming and its going present interesting, 

 sometimes fantastic, forms of clouds that are 

 continually torn, scattered and reunited by the 

 drive forward of the wind. Usually the cloud 

 is a thick one, and in its lowest part is dark, 

 becoming lighter in its main body, and if it is 

 a towering, cumulus cloud, its upper peaks may 

 sometimes be seen before or after the storm, 

 shining white in the sunlight. Beautiful by 

 day, all the forms of thunder-clouds are even 

 more beautiful by night, when lightning flashes 



Th*Jlrt 

 heavy rain- 

 fall. 



Thundtr- 

 $torm. 



