HUTCHISON'S OBJECTIONS, WITH REPLIES. 453 



Objections by Mr. Graham Hutchison, of Glasgow , with 



Replies. 



202. DEAR SIR, Last winter, I carefully read all the 

 papers regarding your meteorological opinions, which you 

 transmitted me. As I did not take notes of the various 

 statements contained in them, I now put down the follow- 

 ing remarks merely from recollection. 



According to your theory, rain, hail, snow, water-spouts, 

 land-spouts, cross currents of air, and barometric fluctua- 

 tions, are all occasioned by one and the same cause, namely, 

 upward vortices of air, produced and maintained by the 

 same means, namely, heat evolved during the condensation 

 of invisible vapor into clouds. And so far as I can ascer- 

 tain from the documents transmitted me, you conceive that 

 all these meteorological phenomena are never produced in 

 any other way. Your theory is both simple and ingenious ; 

 but I find great difficulty in conceiving how the various 

 meteorological phenomena presented to observation in this, 

 and in other countries, can be reconciled therewith, or 

 explained thereby. I shall state what appear to me to be 

 imperfections in your theory, and objections that may be 

 urged against it, just as they suggest themselves. 



1st. I find no account given in your theory how the con- 

 densation of invisible vapor into cloud, which gives out the 

 heat that occasions the upward aerial vortex, commences. 

 And admitting, for the sake of argument, that rain is 

 always, and only, occasioned by an upward aerial vortex, 

 which, according to your theory, so far as I understand it, 

 possesses the principle of self-perpetuation, I find no expla- 

 nation given of how the upward vortex, and the rain there- 

 by occasioned, should ever cease, when once it has com- 

 menced. Let us consider these two points separately. 



Rain never begins to descend till the clouds have acquired 

 a considerable degree of density. But your theory gives 



