Vertical Component of Magnetic Force. 



377 



TABLE XLI. — Means of the Diurnal Ranges of the Vertical Component of Magnetic Force, with 

 reference to the Moon's Age, Declination, and Distance from the Earth, for 1844. 



Moon's 

 Age. 



Mean 

 Diurnal 

 Range. 



Moon's 

 Age. 



Mean 

 Diurnal 

 Range. 



After 



Moon 



farthest 



North. 



Mean 

 Diurnal 

 Range. 



After 



Moon 



farthest 



North. 



Mean 

 Diurnal 

 Range. 



Before 



and 



after 



Perigee. 



Mean 

 Diurnal 

 Range. 



Before 



and 



after 



Apogee. 



Mean 

 Diurnal 

 Range. 



Dav. 



15 



0-00 



1150 



Day. 



6 



0-00 

 0748 



Day. 

 



0-00 



0591 



Day. 

 14 



0-00 



0591 



Day. 



7 



0-00 

 0806 



Day. 



7 



0-00 

 0880 



16 



1230 



1 



0488 



1 



0494 



15 



0678 



6 



0638 



6 



0754 



17 



1226 



2 



0513 



2 



0844 



16 



0417 



5 



1221 



5 



0996 



IS 



1250 



3 



0366 



3 



0634 



17 



0963 



4 



0790 



4 



0765 



19 



1362 



4 



0385 



4 



1070 



18 



0793 



3 



0651 



3 



1228 



20 



0758 



5 



0589 



5 



1172 



19 



0919 



2 



0702 



2 



1541 



21 



0744 



6 



0448 



6 



0898 



20 



0835 



1 



0905 



1 



0945 



22 



0559 



7 



0457 



7 



0859 



21 



0995 



P 



0688 



A 



0877 



23 



0440 



8 



0867 



8 



0794 



22 



0785 



1 



0915 



1 



0441 



24 



0435 



9 



0980 



9 



0766 



23 



0800 



2 



0736 



2 



0524 



25 



0566 



10 



1309 



10 



0672 



24 



1189 



3 



0595 



3 



0523 



26 



0342 



11 



0888 



11 



0484 



25 



0868 



4 



0561 



4 



0577 



27 



0425 



12 



1491 



12 



0706 



26 



0928 



5 



1045 



5 



0604 



28 



0453 



13 



1197 



13 



0609 



27 



0650 



6 



0716 



6 



0826 



29 



0384 



14 



1334 











7 



0887 



7 



0904 



Table XLI. has been formed from Table XL. in the manner described for Table II. 



Variations of the Diurnal Range of the Vertical Component with reference to the Moon's Age. — The means 

 in the first portion of Table XLI. shew that the diurnal range of the vertical component is a minimum about 

 conjunction and a maximum about opposition. The following are means of groups : — 



14 days to 16 days, Full Moon, 0-001238 



17 20 ... 0-001149 



21 24 ... 0-000544 



25 28 ... 0-000446 



29 days to 1 day, New Moon, 0-000540 



2 5 days, 0-000463 



6 9 ... 0-000688 



10 13 ... 0-001221 



Here also, as in the case of the horizontal component, there is an appearance of a secondary maximum at 

 New Moon, but it is not by any means distinct. 



Variations of the Diurnal Range of the Vertical Component with reference to the Moon's Declination. — This 

 result is also well marked in the means in the second portion of Table XLI. The diurnal range of the vertical 

 component is a minimum when the moon has its greatest north and south declination, and it is a maximum 

 when the moon is near, but north of, the equator. The following are means of groups : — 



27 days to 1 day, Moon farthest North, 0-000578 



2 5 days, 0-000930 



6 8 ... 0-000850 



9 12 ... 0-000657 



13 days to 15 days, Moon farthest South, 0-000626 



16 19 ... 0-000773 



20 22 ... 0-000872 



23 26 ... 0-000946 



MAG. AND MET. OBS. 1844. 



5c 



