396 



Results of Makeestoun Observations, 1844. 



Variations of Total Magnetic Force with reference to the Moon's Age. — It is evident, from the first portion 

 of Table LVII., that the total force is a minimum about opposition and a maximum about conjunction ; this 

 will also appear in the following means of gi'oups : — 



14 days to 16 days, Full Moon, 0-000017 



17 20 ... 0000068 



21 24 ... 0000135 



25 28 ... 0-000130 



29 days to 1 day, New Moon, 0-000132 



2 5 days, 0-000126 



6 9 ... 0-000133 



10 13 ... 0-000034 



The value of the force does not vary greatly for the 10 days before and the 10 days after conjunction, the 

 mean value being 0000131 ; the mean for the remaining 10 days, including opposition, being 0-000034. There 

 is a slight appearance of a secondary minimum at conjunction, the maxima occurring before and after that epoch. 

 The incomplete series of observations for 1843 gave nearly the same result, the secondary minimum at con- 

 junction being better marked. 



Variations of the Total Magnetic Force with reference to the Moon's Declination.- 

 of groups of the second portion of Table LVII. : — 



-The following are means 



27 days to 1 day. Moon farthest North, 0-000123 



2 5 days, 0-000070 



6 8 ... 0-000060 



9 12 ... 0-000054 



13 days to 15 days, Moon farthest South, 0-000103 



16 19 ... 0-000091 



20 22 ... ■ 0-000054 



23 26 ... 0-000058 



The simple means and the means of groups indicate that the total magnetic force is a maximum when the 

 moon has its greatest north and greatest south declination ; it is a minimum between these epochs. This result 

 also was obtained from the incomplete series of observations for 1843. 



TABLE LVIII. — Diurnal Variations of the Total Magnetic Force in 1844, as deduced from 



Tables XXVIL and XLIII. 



