Thirty-first Annual Meeting 197 
Nor, so far as known, have the lightning and thunder any 
influence on the formation, progress and termination of the 
thunder-storm, although they may and often do constitute 
the most impressive, spectacular, and even tragic features of 
the storm. For as Prof. Humphreys well says,? “‘No matter 
how impressive or how terrifying these phenomena may be, 
they never are anything more than mere incidents to or products 
of the peculiar storms they accompany. In short, they are 
never in any sense either storm-originating or storm-controlling 
factors.”’ 
3. Source of the Lightning 
Since we cannot have a thunderstorm without thunder, 
and cannot have thunder without lightning, it seems quite 
essential to a proper understanding of these storms to get a 
correct, scientific explanation of the source or cause of the 
lightning. Oh, yes, we are fully aware of the danger just here— 
namely, how easily and how quickly one may get beyond his 
depth when talking about the origin of electricity. We must 
admit, of course, that we know very little if anything for 
certain at this point, but then we would like to appear to know 
something about this interesting phase of our discussion. We 
are deeply indebted to Dr. G. C. Simpson® of the Indian 
Meteorological Department for our best information or knowl- 
edge on this point. Dr. Simpson, by numerous observations and 
laboratory experiments found out a great many extremely 
valuable-things concerning the electricity brought down by the 
raindrop and the snowflake, and at the same time, by means 
of a number of well-devised experiments, determined the 
electrical effects of each obvious process that takes place in 
the thunderstorm. He found out, for example, that no elec- 
trification resulted from freezing and thawing, air-friction, etc., 
but that when he allowed drops of distilled water to fall through 
a vertical blast of air of sufficient strength to produce some 
spray, 
(1) That breaking of drops of water is accompanied by the 
production of both positive and negative ions. 
(2) That three times as many negative ions as positive ions 
are released. 
as 
“‘Now,’’ as pointed out by Professor Humphreys’, “a 
strong upward current of air is one of the most conspicuous 
