NOTES. 



PAG. 6. NOTE I. We regard hère as knoen tbe beautiful recherches of Wells (An 

 essay on Dew etc. London 1815) and otlier on the matter of Dew and its depending on 

 varous circumstances. 



PAG. 10. NOTE II. From tlie hypothesis on the moveable eqnilibrium of tempéra- 

 ture, the process is more complicated. The bulb of the thermometer radiâtes heat to the 

 atmosphère and to the sjiacc ontside it, both of which, especially the former, give heat back 

 trough radiating. If we call the former quantity of heat TJ and the latter IT we shall get 

 a quantity of lost heat 



V - U 



The same will be the case from the surface of the earth. The bulb of the thermometer 

 receives from it the quantity u and gives to it the quantity n' hence the gain of heat will be 



or the whole loss of heat 



V + u—{'ü' + n)=Q. 



This loss of heat may now be accurately estimated, if the worth of the bulb in water 

 (pc) is known, as well as the number of degrees tlie thermometer has fallen. 



PAG. 17. NOTE III. A comprehensive and valuable treatise, in which the destruction 

 of vegetation by frost etc. is thoroughly analysed, was published in Landtwirtsch, Jahrh. 1886 

 by Herr Miiller-Thorgau, which treatise, trough the kindness of M:r Rindell, I was-able 

 to obtain. 



PAG. 22. NOTE IV. The difficulties attending an exact calculation of the quantity 

 of heat radiated from the surface of the earth, are very great. If the formula of Dulong 

 and Petit is applied, in the form given to it by Peclet, i. e. 



Q =124,72 K a" [«'-1] 



the quantities having the same signification as is said page 19. 



This formula will be valid, supposing e and t to be constant, which is evidently not 

 the case here. In the first place the température of the surroundings falls very rapidly 

 because vegetation, on radiating heat to space, is cooled, and cold air pours down to the 



