Results of Makerstoun Observations, 1844. 



TABLE XLVII. — Mean Variations of the Vertical Component of Magnetic Force, with reference 

 to the Moon's Hour- Angle for each Lunation, for the Six Winter and Six Summer Lunations, 

 and for the Twelve Lunations, of 1844. 



Moon's 

 Hour- 



Lunations. 



















i 













Angle. 



1st. 



2d. 



3d. 



4th. 



5th. 



6th. 



7th. 



8th. 



9th. 



10th. 



11th. 



12th. 



Win- 

 ter; 



Sum- 

 mer. 



Year. 



h. 



0-00 



o-oo 



o-oo 



0-00 



o-oo 



o-oo 



o-oo 



o-oo 



O'OO 



o-oo 



o-oo 



O'OO 



o-oo 



o-oo 



0-00 







0061 



0004 



0139 



0282 



0035 



0126 



0055 



0089 



0048 



0117 



0079 



0047 



0025 ; 



0062 



0035 



1 



0096 



0029 



0057 



0130 



0060 



0140 



0045 



0071 



0004 



0000 



0095 



0069 



0008 



0031 



0011 



2 



0065 



0057 



0031 



0078 



0087 



0127 



0026 



0069 



0009 



0002 



0043 



0129 



0005 



0022 



0005 



3 



0053 



0084 



0035 



0085 



0106 



0128 



0017 



0060 



0000 



0054 



0000 



0071 



0000 



0022 



0003 



4 



0052 



0097 



0000 



0020 



0110 



0126 



0043 



0065 



0004 



0135 



0020 



0058 



0011 



0018 



0006 



5 



0034 



0119 



0080 



0000 



0094 



0119 



0081 



0038 



0026 



0173 



0023 



0028| 



0027 



0016 



0013 



6 



0028 



0105 



0045 



0037 



0081 



0080 



0078 



0018 



0042 



0204 



0050 



0011 



0024 



0012 



0010 



7 



0005 



0038 



0103 



0082 



0078 



0061 



0062 



0000 



0019 



0128 



0080 



0006 1 



0010 



0007 



0000 



8 



0027 



0046 



0170 



0067 



0000 



0055 



0071 



0033 



0035 



0123 



0069 



0005 



0024 ! 



0000 



0003 



9 



0019 



0075 



0166 



0058 



0042 



0043 



0062 



0046 



0014 



0172 



0083 



ooooi 



0036 



0001 



0010 



10 



0024 



0090 



0195 



0035 



0085 



0075 



0072 



0081 



0033 



0235 



0110 



0022; 



0063 



0020 



0033 



11 



0038 



0127 



0286 



0054 



0110 



0070 



0045 



0095 



0040 



0298 



0103 



0047 i 



0100 



0025 



0054 



12 



0016 



0132 



0346 



0047 



0071 



0055 



0005 



0090 



0063 



0396 



0124 



0078 ! 



0132 



0012 



0063 



13 



0000 



0163 



0438 



0065 



0090 



0000 



0000 



0106 



0088 



0424 



0152 



0097; 



0163 



0015 



0080 



14 



0020 



0159 



0460 



0101 



0119 



0038 



0033 



0077 



0112 



0541 



0176 



0106! 



0194 



0036 



0107 



15 



0056 



0172 



0489 



0109 



0101 



0045 



0054 



0101 



0098 



0475 



0196 



0093 



0197 



0041 



0111 



16 



0056 



0182 



0435 



0144 



0078 



0043 



0071 



0144 



0173 



0509 



0177 



0084 



0191 



0065 



0119 



17 



0062 



0169 



0426 



0185 



0049 



0040 



0075 



0150 



0220 



0458 



0163 



0064 1 



0174 1 



0076 



0117 



18 



0085 



0080 



0298 



0092 



0063 



0019 



0084 



0140 



0223 



0334 



0159 



0078 



0123 ! 



0060 



0083 



19 



0100 



0109 



0325 



0073 



0037 



0030 



0082 



0053 



0210 



0338 



0254 



0078 



0151 ; 



0037 



0086 



20 



0089 



0078 



0231 



0083 



0033 



0033 



0075 



0045 



0201 



0318 



0258 



0071 j 



0125 



0035 



0071 



2J 



0089 



0085 



0246 



0134 



0065 



0038 



0059 



0049 



0168 



0310 



0337 



0059 



0138 



0042 



0081 



22 



0091 



0019 



0176 



0165 



0046 



0050 



0070 



0067 



0138 



0286 



0334 



0060 1 



0111 



0046 



0070 



23 



0084 



0000 



0130 



0120 



0082 



0075 



0060 



0111 



0097 



0040 



0327 



0061 j 



0058 



0047 



0044 



24 



0056 



0009 



0135 



0150 



0078 



0100 



0055 



0127 



0049 



0101 



0351 



0055 



0068 



0050 



0050 



Diurnal Variation with reference to the Moon's Hour-Angle. — Considering the variations for the six winter 

 lunations, the six summer lunations, and for the year, as given in the last three columns of Tahle XLVII. 



In the winter group, the maximum of the vertical component occurs ahout 2 J hours after the moon's transit 

 of the inferior meridian, and the minimum ahout 3 hours after its transit of the superior meridian. 



In the summer group, there are two maxima and two minima ; the principal minimum occurs 4 hours 

 hefore the moon's inferior transit, and the principal maximum occurs 4^ hours after the inferior transit ; a 

 secondary minimum occurs about 4^ hours before the superior transit, and a secondary maximum at the 

 superior transit. 



In the mean of the 12 lunations in 1844, the maximum occurs 3-iy hours after the inferior transit, and 

 the minimum occurs 7 hours after the superior transit. There is a secondary maximum immediately before 

 this epoch, but it is not well marked. The remarks already made for the similar discussion of the horizontal 

 component also apply here. In order to eliminate the effect of disturbances, those observations were rejected 

 in the summations, which were considerably disturbed, differing from the monthly means at the corresponding 

 hours by more than 50 micrometer divisions ( = - 000500), quantities interpolated from the preceding and 

 succeeding observations having been substituted. The following are the resulting variations at intervals of §£ 

 of an hour: — 



0-0000 



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 



37 31 29 22 17 20 06 00 04 12 24 32 47 59 73 77 83 70 58 43 40 39 34 39 36 



The maximum occurs about 2 hours after the moon's passage of the inferior meridian, and the minimum 

 7 hours after the superior transit ; there is an ill-defined minimum about 3 hours before the superior transit, 

 and maximum at the superior transit. 



