Vertical Component of Magnetic Force. 



385 



These differences give the same law as the differences discussed above. The maximum positive effect 

 occurs about 5J h p.m., and the maximum negative about l h a.m. ; whence, as in the analogous discussions for 

 the magnetic declination and horizontal component, we may conclude that the smallest and largest disturbances 

 obey the same diiu*nal law. (See pp. 345 and 368.) 



Differences of the Individual Observations from the Monthly Means for the Corresponding Hours. — Adopting 

 the process already indicated for the magnetic declination, p. 346, we obtain the following Table : — 



TABLE L. — Mean Difference of a Single Observation of the Balance Magnetometer from the Monthly 

 Mean, at the corresponding hour, for each Civil Day and Week in 1844. 



Civil 

 Day. 



Jan. 



Feb. 



March. 



April. 



May. 



June. 



July. 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 





Mic. Div. 



Mic. Div. 



Mic. Div. 



Mic. Div. 



Mic. Div. 



Mic. Div. 



Mic. Div. 



Mic. Div. 



Mic. Div. 



Mic. Div. 



Mic. Div. 



Mic. Div. 



1 



15-6 



32-6 



24-3 



24-9 



23-1 



6-6 



6-5 



31-5 



[18-9] 



132-9 



13-2 



[12-4] 



2 



17-7 



30-5 



40-5 



30-6 



15-4 



[15-1] 



11-2 



19-2 



14-5 



35-2 



14-5 



9-2 



3 



12-6 



19-2 



[32-6] 



19-3 



27-0 



19-6 



9-5 



18-4 



131 



21-8 



[14-5] 



7-7 



4 



121 



[23-0] 



24-2 



12-9 



33-0 



14-6 



11-6 



[17-9] 



14-9 



21-8 



13-0 



11-5 



5 



18-2 



23-5 



28-2 



9-4 



[23-9] 



18-2 



10-6 



9-9 



10-9 



21-4 



12-5 



11-3 



6 



10-6 



18-7 



55-9 



29-9 



18-9 



14-6 



8-6 



111 



16-9 



[19-3] 



14-7 



5-4 



7 



[12-8] 



13-3 



50-5 



[18-1] 



21-0 



13-9 



[14-1] 



17-2 



18-2 



19-1 



16-4 



6-7 



8 



140 



22-5 



35-5 



19-8 



28-2 



11-0 



23-7 



17-2 



[16-0] 



14-3 



17-9 



[8-2] 



9 



11-3 



12-5 



17-4 



18-3 



29-6 



[10-5] 



16-5 



34-0 



17-2 



17-6 



10-9 



7-5 



10 



10-9 



11-7 



[27-7] 



18-2 



20-6 



5-5 



13-5 



101 



14-1 



19-7 



[15-2] 



7-9 



11 



8-3 



[11-6] 



18-5 



120 



28-8 



12-7 



12-2 



[16-5] 



190 



18-7 



20-5 



10-6 



12 



7-2 



7-1 



26-4 



14-9 



[23-2] 



5-2 



6-6 



10-7 



14-5 



16-3 



14-0 



14-7 



13 



7-5 



5-8 



17-8 



25-2 



16-2 



8-6 



11-5 



14-5 



14-0 



[17-0] 



11-5 



12-8 



14 



[7-9] 



100 



24-7 



[32-3] 



12-5 



6-6 



[11-1] 



12-3 



9-1 



17-9 



9-5 



34-9 



15 



9-3 



24-0 



20-0 



16-8 



31-8 



16-7 



13-4 



160 



[12-7] 



13-6 



14-4 



[14-8] 



16 



7-4 



14-5 



25-0 



15-3 



9-7 



[11-2] 



120 



12-7 



15-3 



15-7 



97-2 



12-4 



17 



7-7 



23-2 



[21-3] 



109-8 



11-1 



13-0 



10-7 



8-0 



14-5 



11-8 



[29-3] 



7-5 



18 



6-1 



[17-8] 



20-0 



23-3 



19-8 



13-8 



10-2 



[12-5] 



8-8 



15-4 



17-0 



6-8 



19 



120 



19-7 



17-1 



16-2 



[14-0] 



8-8 



4-2 



13-7 



11-4 



14-4 



19-5 



101 



20 



6-6 



130 



21-2 



16-9 



16-2 



121 



10-6 



13-4 



36-4 



[25-8] 



18-5 



15-0 



21 



[7-4] 



12-4 



151 



[18-4] 



13-5 



190 



[8-3] 



11-5 



14-7 



93-1 



11-8 



250 



22 



7-3 



12-9 



18-7 



15-3 



13-8 



7-9 



9-0 



23-2 



[17-1] 



9-3 



44-5 



[11-7] 



23 



8-4 



9-1 



17-3 



19-2 



47-7 



[16-6] 



9-9 



34-1 



10-8 



10-7 



40-6 



5-9 



24 



3-8 



9-7 



[19-0] 



19-5 



11-5 



10-3 



5-8 



15-6 



12-9 



11-7 



[22-5] 



7-5 



25 



37-2 



[9-2] 



18-7 



22-7 



11-8 



21-9 



27-0 



[18-5] 



16-5 



12-8 



11-5 



6-4 



26 



12-9 



6-9 



19-7 



16-5 



[21-0] 



28-4 



14-7 



11-2 



77-6 



39-6 



12-3 



7-6 



27 





7-6 



24-7 



26-6 



22-0 



24-6 



18-5 



10-0 



18-3 



[17-9] 



14-5 



12-7 



28 



[20-8] 



8-8 



17-2 



[19-6] 



17-1 



221 



[23-5] 



16-5 



20-6 



15-8 



19-0 



5-6 



29 



14-7 



22-6 



28-4 



14-6 



16-2 



23-2 



22-8 



19-8 



[54-7] 



13-0 



11-7 



[16-7] 



30 



17-7 





137-4 



13-9 



16-4 



[16-2] 



22-9 



33-9 



43-5 



14-2 



15-0 



33-3 



31 



21-5 





[43-0] 





15-1 





34-8 



17-4 





18-9 





24-3 



Jan. 



Feb. 



March. 



April. 



May. 



June. 



July. 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 



123 



157 



294 



224 



203 



144 



137 



172 



191 



247 



199 



123 



Annual Variation of the Mean Difference for the Vertical Component. — The average difference of an 

 observation in each month, from the monthly mean at the corresponding hour, is as follows, in parts of the 

 vertical component. 



0-000 _ 



These quantities give the same annual law as the similar discussions of the two other elements. The 

 maximum disturbance of the vertical component occurs near the equinoxes, and the minimum near the solstices. 

 The effect of disturbance is greatest on the means for this component ; the amount of disturbance of the 

 individual observations (independently of sign), is also much the greatest for the vertical component ; the 

 average difference of a single observation from the monthly mean for the corresponding hour is from -J to ^ of 

 the mean diurnal range as deduced from the whole series of observations for each month of the year. 



The mean difference of an observation of the vertical component for the year 1844 = 0000 184. 



MAG. AND MET. OBS. 1844. 



5 E 



