250 



Abstracts of the Makerstoun Observations, 1843. 



TABLE XXIV. — Variations of Magnetic Dip, with reference to the Moon's Age, Declination, and 

 Distance from the Earth, as deduced from Tables IX. and XVI. 





Variations 





Variations 



After 



Variations 



After 



Variations 



Before 



Variations 



Before 



Variations 



Moon's 



of 



Moon's 



of 



Moon 



of 



Moon 



of 



and 



of 



and 



of 



Age. 



Magnetic 

 Dip. 



Age. 



Magnetic 

 Dip. 



farthest 

 North. 



Magnetic 

 Dip. 



farthest 

 North. 



Magnetic 

 Dip. 



after 

 Perigee. 



Magnetic 

 Dip. 



after 

 Apogee. 



Magnetic 

 Dip. 



Days. 



15 



0-393 



Days. 







0-061 



Days. 







0-178 



Days. 



14 



0-157 



Days. 



7 



0115 



Days. 



7 



0-263 



16 



0-187 



1 



0-131 



1 



0-189 



15 



0-187 



6 



0-179 



6 



0-326 



17 



0-298 



2 



0-052 



2 



0164 



16 



0-251 



5 



0-273 



5 



0161 



18 



0-140 



3 



0-144 



3 



0-154 



17 



0-200 



4 



0-438 



4 



0-223 



19 



0-210 



4 



0-072 



4 



0-392 



18 



0-134 



3 



0-312 



3 



0142 



20 



0-159 



5 



0-036 



5 



0-374 



19 



0-080 



2 



0-166 



2 



0179 



21 



0-103 



6 



0-237 



6 



0-340 



20 



0-046 



1 



0-245 



1 



0136 



22 



0083 



7 



0-263 



7 



0-251 



21 



0-184 



P 



0-204 



A 



0-240 



23 



0-211 



8 



0-221 



8 



0-127 



22 



0-085 



1 



0-155 



1 



0000 



24 



0-053 



9 



0-309 



9 



01 64 



23 



0-143 



2 



0181 



2 



0-115 



25 



0-168 



10 



0-347 



10 



0-260 



24 



0-121 



3 



0-214 



3 



0-136 



26 



0-083 



11 



0-307 



11 



0000 



25 



0-142 



4 



0-154 



4 



0-204 



27 



0-000 



12 



0-205 



12 



0-136 



26 



0-200 



5 



0-103 



5 



0192 



28 



0-111 



13 



0-300 



13 



0-147 



27 



0-172 



6 



0-029 



6 



0-089 



29 



0-150 



14 



0-167 











7 



0-167 



7 



0-092 



Vakiations of Magnetic Dip, with reference to the Moon's Age. 



A glance at the quantities in the first portion of Table XXIV. will at once shew that the dip is a maximum 

 when the sun and moon are in opposition, and that it is a minimum when they are in conjunction. This result 

 is perhaps more distinct in the following 



Means of Groups. 



14 days to 16 days, Full Moon, 0'-249 



17 20 ... 0'-202 



21 24 ... 0'-112 



25 28 ... 0'-090 



29 days to 1 day, New Moon, 0'-114 



2 5 ... 0'-076 



6 9 ... 0'-257 



10 13 ... 0'-290 



The maximum of dip occurs in these means rather before full moon, and there is an indication of a secondary 

 maximum at the time of new moon, the minima occurring immediately before and after ; this indication of a 

 secondaiy maximum is probably too indistinct to be trusted. 



Variations of Magnetic Dip, with reference to the Moon's Declination. 



Means of Groups. 



27 days to 1 day, Moon farthest North, 0'-180 



2 5 ... 0'-27l 



6 8 ... " 0'-239 



9 12 ... 0'-140 



13 days to 15 days, Moon farthest South, 0'-164 



16 19 ... 0'-166 



20 22 ... 0'-105 



23 26 ... 0'-151 



*' 



The result from these means does not seem very distinct ; on the whole, there seems to be a maximum of 

 dip about the time the moon is on the equator moving southwards, and a minimum about the time it is on the 

 equator moving northwards. 



