346 



Results of Makerstoun Observations, 1844. 



TABLE XIV. — Mean difference of a Single Observation from the Monthly Mean at the 

 corresponding hour, for each Civil Day in 1844. 



Civil. 

 Day. 



Jan. 



Feb. 

 2-69 



March. 



April. 



May. 



June. 



July. 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 



1 



1-49 



1-40 



2-46 



2-53 



1-16 



1-62 



2-97 



[1-72] 



7-79 



1-65 



[1-94] 



2 



1-45 



1-51 



2 



35 



2-43 



1 



36 



[1 



08] 



1-25 



2-31 



1 



28 



2-35 



2-19 



109 



3 



0-72 



1-75 



[2 



61] 



2-66 



2 



05 



1 



01 



100 



1-87 



1 



28 



1-94 



[1-82] 



0-68 



4 



0-74 



[2-05] 



3 



62 



1-79 



1 



05 



1 



11 



1-25 



[2-11] 



1 



30 



1-62 



2-20 



2-61 



5 



2-57 



2-17 



3 



03 



1-54 



[1 



57] 







74 



0-74 



2-34 



1 



00 



1-38 



1-68 



1-44 



6 



2-76 



1-78 



3 



10 



2-60 



1 



87 







65 



1-00 



1-43 



1 



27 



[1-65] 



1-37 



0-98 



7 



[1-72] 



2-39 



4 



10 



[1-60] 







80 



1 



02 



[1-40] 



1-77 



1 



41 



1-59 



1-28 



0-72 



8 



1-52 



2-27 



3 



65 



0-95 



2 



29 







94 



1-77 



1-10 



[1 



35] 



1-87 



1-35 



[0-99] 



9 



1-32 



1-16 



2 



45 



1-35 



1 



99 



[0 



87] 



1-89 



2-40 



1 



19 



1-47 



1-67 



0-78 



10 



1-38 



1-24 



[2 



27] 



1-37 



1 



02 







83 



1-71 



1-43 



1 



67 



1-71 



[1-80] 



111 



11 



1-29 



[1-26] 



1 



10 



1-21 



1 



36 







94 



0-67 



[1-28] 



1 



53 



1-47 



2-60 



092 



12 



1-17 



1-00 



1 



17 



1-02 



[1 



41] 







86 



1-52 



0-85 



1 



12 



1-44 



2-72 



0-60 



13 



0-65 



0-87 



1 



53 



0-92 



1 



01 



1 



22 



103 



1-20 



1 



23 



[1-56] 



115 



0-67 



14 



[0-88] 



1-00 



1 



14 



[2-04] 



1 



70 







92 



[1-20] 



0-69 



2 



16 



1-82 



1-66 



117 



15 



0-59 



1-24 



1 



17 



1-17 



1 



38 







67 



112 



112 



[1 



58] 



1-22 



1-56 



[1-02] 



16 



0-54 



0-59 



1 



12 



1-07 



1 



04 



[1 



35] 



1-15 



1-32 



1 



58 



1-68 



8-02 



1-55 



17 



102 



1-38 



[1 



46] 



6-87 



1 



16 



2 



35 



1-67 



1-43 



1 



96 



1-84 



[2-80] 



107 



18 



1-31 



[0-95] 



2 



25 



1-32 



1 



07 



1 



78 



2-16 



[1-10] 



1 



47 



2-20 



2-31 



104 



19 



0-77 



0-97 



1 



95 



1-20 



[1 



52] 



1 



17 



1-02 



0-73 



1 



41 



1-22 



1-96 



1-95 



20 



109 



0-71 



1 



12 



0-74 



1 



10 







74 



0-56 



0-87 



3 



77 



[2-36] 



1-31 



3-44 



21 



[1-06] 



0-85 







93 



[1-26] 



1 



98 



2 



97 



[1-15] 



109 



1 



52 



5-54 



1-42 



2-72 



22 



115 



0-98 



1 



23 



1-32 



2 



80 



1 



25 



1-85 



2-48 



[2 



08] 



1-76 



5-58 



[1-75] 



23 



1-44 



0-80 



1 



23 



1-71 



3 



45 



[1 



31] 



0-52 



3-22 



1 



35 



1-62 



4-51 



0-80 



24 



0-61 



0-86 



[1 



32] 



1-27 



1 



45 



1 



10 



0-81 



2-75 



1 



44 



1-59 



[2-64] 



0-97 



25 



3-84 



[1-20] 



1 



43 



3-42 



1 



51 







51 



2-95 



[2-15] 



3 



02 



4-82 



1-25 



0-64 



26 



0-78 



0-90 



1 



40 



2-48 



[1 



84] 



1 



30 



1-76 



1-47 



4 



63 



4-60 



1-77 



0-87 



27 



1-95 



111 



1 



69 



2-47 



1 



47 







57 



2-43 



1-40 



3 



68 



[2-61] 



1-30 



113 



28 



[1-78] 



2-52 



1 



85 



[2-37] 



1 



86 







43 



[2-04] 



1-54 



2 



29 



1-60 



3-34 



1-71 



29 



102 



2-14 



3 



25 



1-18 



1 



30 



1 



75 



1-24 



1-30 



[4 



06] 



1-48 



2-13 



[1-87] 



30 



1-51 





7 



94 



2-15 



1 



57 



[1 



10] 



1-59 



2-87 



3 



60 



1-58 



1-77 



3-68 



31 



1-59 





[3-43] 





0-92 





2-25 



2-28 





1-82 





1-97 



Annual Variation of the Differences for the Magnetic Declination. — The following are the mean differences 

 for each month : — 



Jan. 



Feb. 



March. 



April. 



May. 



June. 



July. 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 



r-34 



l'-40 



2'-22 



l'-87 



l'-60 



1' 12 



l'-43 



r-7i 



l'-93 



2'-26 



2'-30 



l'-40 



There are here two maxima and two minima ; the principal minimum occurs in June, and the principal 

 maximum in October and November ; the mean for the three months, May, June, and July, is l'*38, which is 

 also the mean for the three months, December, January and February. The law of the variations may be stated 

 as follows : — The mean difference of hourly observations from their corresponding monthly means is a minimum 

 near the solstices, and a maximum near the equinoxes. This result is in accordance with that already obtained 

 in the discussion for the diurnal range. 



.. 



