230 



Lieut. Hennessey on Actinometricai 



[Dec. 22, 



Thus at Dehra, October 28, we have the result 880 observed. The corre- 

 sponding result at Mussoorie (i. e. at ll h 15 m ) is found from the diagram 

 to be 945. Proceeding in this manner, and taking averages of all results 

 within 5 minutes of one another to make one result, we find : — 



Table III. 







M. 



D. 



M— D. 







M. 



D. |m-D. 





h m s 

















h m s 









27th. 



11 49 30 



1007 



876 



131 



3rd. 



11 15 45 



1002 



927 



75 





9 53 



969 



904 



65 





11 30 



1008 



918 



90 





29 30 



94 1 



888 



53 





11 36 30 

 11 45 30 



IOIO 



1013 



916 

 912 



94 

 101 







972 



889 



83 





000 

 15 



1006 

 1015 



908 

 929 



98 

 86 



2.8 th. 



1 1 1 5 





880 



6c 





30 



1005 



Q24. 



81 





11 20 



943 



881 



62 





° 4o u 





937 



83 







956 



890 



66 















11 41 30 















1 18 



967 



876 



9 1 







IOIO 



921 



89 





21 30 



928 



884 



44 



1 



4th. 





847 









33 30 



937 



885 



5* 



8 3 30 



718 



129 















8 13 



865 





1 26 



















946 



883 



63 





9 11 23 



943 



823 



120 













10 8 45 



996 



870 



120 



29th. 



3 45 



984 



897 



87 





11 9 45 



1 00 1 



905 



96 





21 30 



965 



907 



58 





11 19 



990 



910 



80 





32 



964 



895 



69 





080 



987 



913 



74 





41 



962 



900 



62 





1 8 45 



984 



894 



90 





1 20 



958 



891 



67 





2 10 



964 



845 



119 





1 33 30 



954 



889 



65 





3 9 3° 



911 



758 



'53 















480 



780 



54 6 



234 



















965 



897 



68 



































Mean from 









30th. 



11 41 48 

 1 30 

 17 35 



981 

 978 

 985 



917 

 904 

 918 



64 

 74 

 67 





n h 9 111 to 

 i h 8 m ... 



| 99 1 



906 



85 







1 9 g i 



913 



68 













And collecting the average daily results of Table III. for +1 hour from 

 noon, we obtain : — 



Table IV. 





M. 



D. 



M-D. 



1869. Oct. 



27. 



972 



889 



83 





28. 



946 



883 



63 





29. 



965 



897 



68 



Nov. 



30. 



981 



9i3 



68 



3- 



IOIO 



921 



89 





4- 



991 



906 



85 



Mean 



978 



902 



76 



which values of M — D and jj are practically identical with those of 

 Table II. 



(] (>) As regards the complete day-curve observed on November 4, it 



