364 



Results of Makerstoun Observations, 1844. 



TABLE XXXI. — Mean Variations of the Horizontal Component of Magnetic Force, with reference 

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

 and for the Twelve Lunations of 1844. 



Moon's 

 Hour- 



Lunations. 

































Angle. 



1st. 



2d. 



3d. 



4th. 



5th. 



6th. 



7th. 



8th. 



9th. 



10th. 



11th. 



12th. 



Win- 

 ter. 



Sum- 

 mer. 



Year. 



h. 



o-oo 



0-00 



O'OO 



o-oo 



o-oo 



o-oo 



o-oo 



o-oo 



o-oo 



o-oo 



o-oo 



0-00 



0-00 



0-00 



00 







0000 



0118 



0384 



0967 



0371 



0321 



0161 



0337 



0232 



0549 



0318 



0153 



0045 



0231 



0049 



1 



0266 



0302 



0276 



0385 



0468 



0294 



0160 



0389 



0228 



0573 



0272 



0098 



0090 



0153 



0033 



2 



0325 



0181 



0000 



0557 



0507 



0461 



0283 



0216 



0104 



0532 



0127 



0084 



0000 



0187 



0005 



3 



0553 



0182 



0202 



0428 



0314 



0368 



0218 



0291 



0172 



0428 



0007 



0351 



0079 



0131 



0016 



4 



0433 



0225 



0771 



0557 



0417 



0421 



0189 



0175 



0288 



0466 



0000 



0389 



0172 



0174 



0084 



5 



0521 



0123 



0039 



0759 



0363 



0329 



0106 



0000 



0280 



0372 



0158 



0356 



0053 



0139 



0007 



6 



0465 



0129 



0428 



0370 



0347 



0400 



0235 



0109 



0139 



0302 



0392 



0351 



0136 



0099 



0029 



7 



0526 



0221 



0622 



0365 



0346 



0246 



0196 



0204 



0371 



0207 



0122 



0242 



0115 



0121 



0029 



8 



0322 



0048 



1014 



0000 



0052 



0531 



0171 



0162 



0160 



0566 



0371 



0356 



0238 



0012 



0036 



9 



0297 



0195 



0283 



0032 



0284 



0483 



0364 



0351 



0351 



0435 



0269 



0449 



0113 



0144 



0040 



10 



0375 



0238 



0734 



0279 



0291 



0277 



0416 



0389 



0025 



0000 



0293 



0427 



0136 



0112 



0036 



11 



0435 



0113 



0575 



0011 



0420 



0385 



0491 



0368 



0169 



0154 



0441 



0365 



0135 



0140 



0051 



12 



0605 



0235 



0847 



0039 



0000 



0382 



0392 



0648 



0491 



0896 



0287 



0325 



0324 



0158 



0152 



13 



0515 



0111 



0636 



0405 



0456 



0405 



0587 



0244 



0655 



0966 



0357 



0244 



0263 



0291 



0189 



14 



0528 



0178 



0958 



0577 



0307 



0461 



0265 



1086 



0650 



0559 



0448 



0295 



0286 



0390 



0250 



15 



0367 



0140 



1224 



0438 



0069 



0402 



0374 



0430 



0498 



0396 



0260 



0385 



0254 



0201 



0139 



16 



0526 



0230 



0669. 



0546 



0234 



0203 



0307 



0494 



0391 



0276 



0329 



0228 



0168 



0195 



0093 



17 



0386 



0395 



0568 



0606 



0032 



0202 



0154 



0356 



0501 



0386 



0182 



0361 



0171 



<*1 11 



0068 



18 



0370 



0242 



0407 



0361 



0115 



0122 



0074 



0202 



0486 



0538 



0386 



0344 



0173 



0059 



0027 



19 



0413 



0329 



0874 



0501 



0350 



0000 



0161 



0270 



0385 



0645 



0503 



0498 



0335 



0111 



0134 



20 



0552 



0312 



0694 



0426 



0370 



0092 



0000 



0108 



0007 



0335 



0407 



0115 



0194 



0000 



0008 



21 



0396 



0315 



0739 



0363 



0301 



0301 



0070 



0116 



0000 



0531 



0647 



0295 



0279 



0025 



0063 



22 



0463 



037? 



0148 0295 



0367 



0400 



0154 



0105 



0020 



0461 



0279 



0253 



0121 



0056 



0000 



23 



0594 



0287 



0784 0496 



0420 



0347 



0155 



0196 



0041 



0255 



0318 



0000 



0165 



0109 



0048 



24 



0468 



0000 



0609 0346 



0332 



0279 



0326 



0217 



0211 



0428 



0472 



0350 



0180 



0118 



0060 



Table XXXI. has been formed in the same manner as Table XI. The numbers in the first column are 



ffths of the moon's hour-angles from the meridian. 



Diurnal Variation of the Horizontal Component with reference to the Moon's Hour-Angle. — In this case, 

 as in that for the magnetic declination, the means for the lunations in winter give a somewhat different law 

 from those for the lunations in summer. The following are the means at nearly two-hourly intervals for the 

 summer and winter groups, and for the whole twelve lunations : — 



Groups, 



Winter,... 0-000 

 Summer, 0-000 



Istl) °- 00 ° 



Oh Qm 



066 

 155 



2 h 25 m 

 000 

 147 



4h 20 m 



073 

 144 



6M5 m 

 086 

 098 



8M0"> 



136 

 066 



10 h 5 m 



096 

 114 



12 h 0- 

 254 

 212 



13i> 55" 



231 

 283 



15h 50" 

 131 



156 



17 h 45™ 

 215 

 073 



19 h 40-° 



197 

 000 



21" 35" 

 104 

 070 



037 000 035 019 028 033 160 184 070 070 025 012 



In the winter group, for which the moon is in opposition north of the equator — 



The maximum occurs about 2 hours after the moon's inferior transit. 

 The minimum 2 hours superior transit. 



If there are secondary maxima or minima, they are not well marked in the means for 1 844. 

 In the summer group, for which the moon is in opposition south of the equator, the variation is distinctly 

 double ; 



The principal maximum occurs about 2 hours after the moon's inferior transit. 



The principal minimum 4 J before superior transit. 



A secondary maximum 2 after 



A secondary minimum 8 after 





