in the Air upon the Temperature of the Ground. 275 



against the theory, because it becomes more and more im- 

 possible to reconcile the chronology demanded by CrolFs 

 hypothesis with the facts of observation. 



1 trust that after what has been said the theory pro- 

 posed in the foregoing pages will prove useful in explaining 

 some points in geological climatology which have hitherto 

 proved most difficult to interpret. 



Addendum*. 



As the nebulosity is very different in different latitudes, 

 and also different over the sea and over the continents, it is 

 evident that the influence of a variation in the carbonic acid 

 of the air will be somewhat different from that calculated 

 above, where it is assumed that the nebulosity is the same 

 over the whole globe. I have therefore estimated the nebu- 

 losity at different latitudes with the help of the chart published 

 by Teisserenc de Bort, and calculated the following table for 



© 



% - 



Nebulosity. 



s § 



a* 



Eeduction factor. 



K=0-67. 



K= 



1-5. 



■ 



H 



a 

 <o 



o 



5 * 



9 



o 



o 



1 

 3 



11 



CD 



-- 1 



1 



O 



70 

























58-1 



667 



72-1 



0-899 



0-775 



0-864 



-2-8 



-2-4 



31 



2-7 



60 

























563 



676 



558 



0-924 



0-763 



0-853 



-30 



-24 



3-3 



2-7 



50 

























457 



633 



52-9 



1057 



0813 



0-942 



-3-5 



-2-7 



3-8 



2-9 



40 

























365 



52-5 



429 



1-177 



0939 



1041 



-3-9 



-3-1 



4-1 



3-3 



30 

























28-5 



47-2 



38-8 



1-296 



1-009 



1-120 



-4-1 



-3-2 



4-5 



3-5 



20 

























28-5 



47-0 



24-2 



1-308 



1017 



1-087 



-41 



-3-2 



4-3 



3-4 



10 



























501 



56-7 



23-3 



1-031 



0-903 



0-933 



-31 



-2-7 



3-3 



2-9 



54-8 



59-7 



24-2 



0-97 



0-867 



0-892 



-29 



-2-6 



3-1 



2-8 



-10 

























47-8 



540 



22-5 



1-056 



0-932 



0-96 



-3-3 



-29 



3-4 



30 



-20 

























29-6 



49-6 



23-3 



1-279 



0-979 



0-972 



-4-1 



-31 



4-2 



3-2 



-30 

























389 



51-0 



125 



1-152 



0-958 



0-982 



-3-8 



-3-2 



4-0 



3-4 



-40 

























62-0 



61-1 



2-5 



86 



0-837 



0-838 



-2-9 



-2-8 



3-2 



31 



-50 

























710 



71-5 



o-s 



0-749 



0-719 



0-719 











-60 





















* C/.p. 265. 



