216 



MR. J. BAXENDELL ON THE 



other part on the opposite side; but the results of this 

 discussion of the Oxford Anemograph Observations seem 

 to show that the greatest easterly deflection of the needle 

 should be taken as the direction of the true magnetic me- 

 ridian — and that the daily oscillations are due to one dis- 

 turbing force only, which, when in operation, acts always 

 in the same direction. 



Table V 





h. h. 

 0—2 



25-18 



h. h. 



2—4 



h. h. 

 4—6. 



« 



h. h. 



6—8 



h. h. 



8—10 



h. h. 

 10—12 



h. h. 

 12-14 



h. h. 

 14—16 



h. h. 



16—18 



h. h. 



18—20 



h. h. 



20—22 



h. h. 



22-0 



Means. 



1859 



24-52 



21-93 



19-88 



18-83 



18-23 



18-23 



18-19 



17-81 



19-13 



21-68 



26-19 



20-82 



1860 



25-5.3 



25-02 



23-04 



21-18 



20-03 



19-32 



18-56 



18.49 



13-31 



19-68 



22-64 



26-24 



21-50 



1861 



23-76 



23-10 



21-18 



18-58 



18-00 



17-39 



17-55 



17-13 



17-51 



18-06 



20-02 



23-34 



19-63 



1862 



24-83 



23-88 



21-60 



19-75 



18-93 



18-71 



18-32 



18-21 



18-28 



19-48 



22-70 



24-79 



20-80 



1863 



25-01 



24-75 



22-63 



20-04 



18-99 



18-54 



1906 



18-33 



18-45 



19-26 



21-77 



25-02 



20-99 



1864 



23-49 



23-89 



21-58 



19-15 



18-03 



17-70 



17-21 



16-65 



16-.39 



17-18 



20-32 



22-88 



19-54 



1865 



22-54 



21-99 



2007 



17-77 



16-74 



16-31 



16-48 



16-26 



16-39 



17-16 



19-92 



22-12 



18-65 



Means. 



24-33 



23-88 



21-72 



19-48 



18-50 



18-03 



17-91 



17-61 



17-59 



18-56 



21-29 



24-36 



20-27 



Differen 



ces 0-4 



5 2-1 



6 2-2 



4 0-98 0-47 0-12 0-30 0-02 -0-97 2-73 3-07 0-03 



Table V. shows the actual mean annual bi-horary velo- 

 cities of the wind for the seven years 1859-65 ; and it will 

 be seen from the differences between the mean values at 

 the foot of the Table that the maximum velocity occurs at 

 about oh. 45 m., the minimum at about 17 h. om., and 

 that during the increase of velocity the rate of change was 

 greatest at about 21 h. 30 m., and during the decrease at 

 about 5 h. 30 m. Here we have the maximum occurring 

 somewhat earlier than when the direction of the wind is 

 taken into account, thus bringing all the phases of the 

 wind changes somewhat in advance, in point of time, of 

 those of the magnetic variations, and indicating therefore 

 that the magnetic disturbances are due to electrical cur- 

 rents generated or modified by changes and disturbances 

 of the atmosphere. 



