104 



REPORT — 1871. 



Table III. (continued). 



reason : while there are only about a dozen registers complete for the four 

 decades, there are thirty-eight which are complete for the last three decades. 

 'Now that we have found the relation between the first two decades, the re- 

 turns for the thirty years are rendered almost as instructive as those for 

 forty years. 



Fig. 3. 



1866 Report. 



1871 Report. 

 All stations. 



90 



We have therefore compiled Table IV., which differs from Table III. only 

 in its being for thirty years instead of forty, and in giving observations from 

 thirty-eight stations instead of twelve. 



J 



