<Bun*3Ftre anfr IRatn 149 



smitten with the craze for ' weather-shooting.' Experi- 

 ments are continued for a few years perhaps, but they 

 only prove that the idea of affecting the weather by 

 the discharge of guns is an exploded one. The agita- 

 tion dies down until the next time. Its reappearance 

 is often due to the invention of some new apparatus, 

 which, of course, is no more effective than any of its 

 predecessors." 



So much for the purely experimental side of the 

 subject. On the theoretical side it should be remem- 

 bered that the energy involved in producing rainfall 

 is enormous. The heat liberated in the condensation 

 of a rainfall of one-tenth of an inch over an area of 

 one square mile, the Doctor pointed out, is the equi- 

 valent of the energy that would be produced by an 

 engine of ten million horse -power in half an hour, 

 compared with which expenditure of power the energy 

 expended in the heaviest cannonade that man can 

 produce must be puny. " We could only expect an 

 effect if the atmosphere were in a state resembling 

 that of a loaded gun, and the explosion provided the 

 analogy of pulling the trigger." But, as Dr. Shaw 

 remarked, there are no grounds for supposing that the 

 atmosphere is in a state of unstable equilibrium such 

 as is demanded by this suggestion. The only instances 

 where we have any evidence of instability are those 

 afforded by violent thunder-squalls. " But even then 

 we have no reason for supposing that we could influence 

 the course of the phenomena by explosives." 



IV 



An American authority, I am told by Mr. M. H. 

 Ilsley, has said that a favourite argument was that 



