Magnetic Declination. 



353 



or 6 h p.m. in June is only half a minute (0'"5) ; about this hour, also, the numbers of positive differences and 

 negative differences are nearly equal ; and since the mean of the observations at 6 h p.m. in June is within half 

 a minute of the monthly mean of all the observations, the probable error of a single observation in June 1 844 

 at 6 h p.m. would be only about 0'-5 from the mean declination for the month : a degree of accuracy which is 

 quite equal to any thing that can be expected from a month's observations with the best portable apparatus. 



TABLE XX. — Number of Positive and Negative Differences which occur between the limits of 



successive Minutes for each Hour in 1844. 



Makerstoun 



0' 



1' 



2' 



3' 



4' 



5' 



6' 



7' 



8' 



9' 



10' 



15' 



20' 



25' 



30' 



Mean Time. 



to 



to 



to 



to 



to 



to 



to 



to 



to 



to 



to 



to 



to 



to 



to 



1'. 



2'. 



3'. 



4'. 



5'. 



6'. 



V. 



8'. 



9'. 



10'. 



15'. 



20'. 



25'. 



30'. 



40'. 



h. 



76 



59 



30 



9 



2 



4 



• • • 





2 





1 



1 









58 



24 



19 



6 



6 





6 



4 



1 



1 



2 



1 



1 









... 



13 { + 



78 



69 



16 



4 



4 



5 



1 



1 



2 



2 



1 















65 



19 



15 



10 



7 



3 



2 



1 



4 



2 



1 



1 





1 







.. 



"{- 



93 



44 



21 



4 



6 



3 



1 



1 



... 



1 





1 













67 



25 



18 



8 



5 



3 



4 



3 



1 





2 















l.|i 



80 



46 



18 



11 



4 



4 



3 





1 







... 











... 



66 



36 



19 



13 



8 



1 



2 



... 



1 





1 



... 













i6 it 



90 



30 



16 



8 



2 



2 



1 



1 



1 



3 



3 













... 



75 



36 



27 



8 



2 



3 



4 





... 





2 



... 













17 1 + 



80 



30 



9 



3 



4 



3 



2 









6 



... 





1 









81 



48 



26 



12 



4 



2 



1 



1 



... 





... 















18 | + 



64 



16 



10 



4 



2 



8 



2 



1 



2 





2 



1 













99 



62 



29 



10 





1 







... 











.. 









19 { + 



61 



28 



13 



5 



7 



3 



... 



1 



2 





1 



2 













91 



68 



27 



2 



2 



1 





... 







... 













.. 



20 { + 



71 



20 



16 



6 



4 



5 



5 



... 



... 





2 













.. 



85 



56 



31 



10 



1 









... 

















.. 



21 {t 



52 



30 



18 



6 



6 



1 



1 



2 



... 



2 



4 















84 



64 



29 



13 



1 





... 











... 













22 { + 



50 



29 



17 



9 



4 





6 



1 



1 





2 















96 



65 



26 



8 



... 





... 









... 















23 { + 



56 



32 



20 



13 



3 



2 



3 



1 







1 













.. 



81 



66 



28 



5 



2 



... 

















.. 









°{ + - 



53 



30 



12 



9 



4 



3 



1 



1 



2 







2 













98 



53 



35 



8 



1 



... 













... 













'{- 



59 



36 



13 



17 



4 



... 



3 





1 





... 















96 



46 



27 



8 



2 



... 











... 















*{ + - 



52 



39 



21 



13 



3 



2 





5 





















77 



68 



22 



6 



2 



2 



2 









... 















.{t 



53 



54 



13 



7 



10 



5 



... 



2 



1 



















75 



63 



15 



5 



6 





1 



1 



... 





1 



1 





.. 









*{! 



73 



38 



19 



8 



5 



6 





1 







... 















87 



50 



14 



2 



1 



2 



2 



2 



1 



1 



1 















*{+ 



70 



42 



20 



11 



6 



1 



2 



... 







1 



... 





.. 







.. 



100 



33 



11 



6 



2 



1 



2 





1 



1 



1 



1 













°{ + - 



80 



41 



27 



23 



7 



5 





2 



1 





... 















63 



26 



9 



6 



5 



1 



5 



3 





1 



6 













2 



>{ + - 



92 



68 



34 



10 



7 





... 





... 





1 















42 



15 



13 



8 



4 



6 



4 



2 



... 



1 



5 



1 













°{ + - 



81 



60 



46 



21 



9 



... 



3 



1 







1 



... 













25 



16 



9 



11 



8 



4 



2 



4 



2 



1 



5 



2 





2 







.. 



°{i 



78 



85 



33 



9 



... 



1 



... 



... 





2 



1 



... 











.. 



36 



12 



15 



10 



7 



10 



6 



3 



3 



... 



2 



1 













10 | + 



86 



87 



22 



9 



3 



2 



2 



2 







... 



... 





... 









30 



20 



14 



11 



6 



6 



3 



1 



1 



3 



3 



1 













11 { + 



74 



65 



44 



16 



7 



1 



1 



... 





... 



... 







.. 









34 



18 



16 



13 



7 



6 



3 



... 



2 



1 



2 



2 





2 





MAG. AND MET. OBS. 1844. 



4u 



