528 Professor Lodge [May 28, 



The experiment illustrates, however, that smoke can be caught and 

 deposited on the wing. 



[Special apparatus for producing and condensing quantities of 

 smoke was next shown in action. It could be kept electrified by a 

 splendid machine kindly lent by Mr. Wimshurst, but a small Voss 

 machine was amply sufficient for the purpose. After the lecture I 

 had an opportunity of trying Mr. Wimshurst's 8 -plate machine on 

 the smoke-chamber, and the rapidity with which it was cleared was 

 surprising. Eoughly speaking it might be called instantaneous.] 



When such a machine as this of Mr. Wimshurst's comes to be 

 used, one may hope to make an impression on fume produced on a 

 manufacturing scale. But further data in this direction are desirable. 



Leaving these sublunary and industrial applications, let us ask 

 finally if there may not perhaps be some possible mode of artificially 

 affecting atmospheric conditions by means of electricity. It certainly 

 seems to me rather probable ; and I should much like to have the 

 means of discharging a large quantity of high-pressure electricity 

 into the air, either for the purpose of acting on a fog, or in the hope 

 of perhaps affecting the weather. 



This much I regard as certain, that if a kite or a captive balloon 

 (a kite for windy days, a balloon for calm ones) be flown into a 

 cloud, and made to give off electricity for some time, that cloud will 

 begin to rain. 



It is just possible, though hardly probable, that by the automatic 

 coalescence of drops into larger ones, the potential of the charge so 

 given could become high enough to cause an artificial thunderstorm. 

 The amount of electricity in a thunderstorm is not very great 

 (Faraday reckoned it as less than the amount in a thimble-full of water, 

 and he was quite right) ; its potential is enormous, but there is 

 certainly some automatic regenerative action going on in the atmo- 

 sphere, which is able to raise the potential of a given charge higher 

 and higher until a flash occurs. 



It is well known, from observations made with Sir W. Thomson's 

 atmospheric recorder, that variations in the electrical condition of the 

 air precede a change of weather, but it is not known which is cause 

 and which is effect in this case. 



With a very large voltaic battery such as that constructed by Dr. 

 de la Rue, or perhaps even a bigger one, of sufficient E.M.F. to give 

 a constant brush discharge from points, a tremendous quantity 

 of electricity could be poured into the atmosphere, and its electrical 

 condition could be certainly disturbed. 



Whether this disturbance would be beneficial or not, is, I know, 

 another matter. I do not see how one is to tell without trying the 

 experiment. 



Perhaps usually the weather is best left alone ; but there are times 

 when any change feels as if it must be for the better. 



Very little is known at present concerning the causes operating in 

 the formation and dissipation of those Cyclones which act so powerfully 



