PART in. THE CYCLE OF A YEAR. 17 



merely a dry and wet bulb arrangement ; that he " ignored 

 all previous use of it," though some other persons had 

 published on what was essentially the same in 1830, 1817, 

 and 1802 ; while the principle may be traced back to 

 Hutton in 1792 and slightly to Cullen in 1777 ;" and that 

 " the only thing which Mason did was to arrange a com- 

 pact form of dry and wet for travelling purposes." 



This last remark plainly shows that the high official 

 writer in the Society's " Quarterly Journal " of last year 

 knew nothing of the severe battle of hygrometry in 

 Madeira, which the dying Dr. Mason had fought so 

 gallantly and won half a century nearly before, and had 

 not read his Madeiran book, where this historical state- 

 ment comes out clearly on its p. 4,^ (< I need only ob- 

 serve here, that the principle of this method of registering 

 humidity and dryness of the atmosphere was first pointed 

 out by the late Dr. James Hutton." 



Whether, after all these labours, the posthumous 

 honour can now be procured of connecting Dr. Mason's 

 name once again with his favourite hygrometer, seems 

 doubtful ; but every additional inquiry into the climate of 

 Madeira at the place, will infallibly bear him out before 

 successive generations in showing the extraordinary 

 influence therein of that invisible climatic agent to whose 

 study he devoted himself ; and which, like some other 

 things we are told of elsewhere, is, though unseen, more 

 important than the things which do appear. 



In gathering up, therefore, the materials for a con- 



c 



