Sbe (Breat Cloufc 2)rive. 1 79 



Then came a series of days in which the great 

 drive went on with endless variety but no cessation. 

 The mornings dawned fair and promising, and it 

 would seem as if the last of the procession had 

 drifted by us in the night. But the middle of the 

 forenoon would see their tops gleaming again in the 

 sun, as they came rolling and tumbling before a 

 fresh breeze or drifting swiftly before a lighter air. 

 Then, by noon, the smaller detachments massed them- 

 selves, darkened into nimbus beneath, dropped a few 

 bolts of lightning and a torrent of rain, and then 

 littered and obstructed the sky till sundown. Some- 

 times the cumulus would be backed and reinforced 

 by those clouds of the upper regions which foretell 

 a storm ; and then the tints would fade out of the 

 lower clouds, they would flatten into a monotony of 

 grey, and another day of rain would make the pre- 

 parations for more cloud processions next day. 



I have often wondered just where the initial point 

 of a thunder-storm might be, and wished that I 

 might see one start. The great cloud drive has 

 afforded plenty of examples. This charging of the air 

 with moisture ; this huddling of the clouds together ; 

 this liberation of electricity with the changes in tem- 

 perature, — has created a score of electrical storms be- 

 fore our very eyes. Sometimes they have come in 

 small and weak detachments ; sometimes they have 

 advanced across a third of the horizon. Twice I 

 have seen one form almost in the zenith, and start 

 from our own village. Twice, moreover, I have seen 



