108 



On Dove's Law of the 



5 from the N.E. to the S.W. quadrant. 

 3 from the N, to S., or vice versa. 

 2 from E. to ¥. 



These figures illustrate, in strict conformity with the 

 theory, how quickly the vane travels hetween E. and N. and 

 W. and S., while it is retarded in the "critical quadrants," 

 viz., S. and E. and N. and W. 



The following table contains the analysis of the facts from 

 which the above results have been derived : — 



Between 



Positive. 



Negative. 



Difference 



S. and S. E. 



1159-5 . 



942-5 . 



. 2170 



S.E. and E. 



668-5 . 



535-5 



. 1330 



E. and N.E. 



816-5 . 



627-5 . 



. 189-0 



N.E. and N. 



1565-5 . 



. 1351-5 



. 2140 



N. and N.W. 



1085-5 . 



880-5 



. 205-0 



N.W. and W. 



1012-0 . 



858-0 



. 154-0 



W. and S.W. 



1118-5 . 



928-5 



. 190-0 



S.W. and S. 



1362-0 . 



. 11230 



. 239-0 



1541-0 

 Sums of positive revolutions throughout 



the year 48'16 



It is evident that the values, as given in the third column, 

 ought to be equal; because, if the vane had to pass forty- 

 eight times round the compass, an equal number of points 

 must have been traversed in each octant, and these dif- 

 ferences are, if we reduce the octants to quadrants, as 

 follows : — 



Between S.E. and N.E 350 



„ N.E. and N.W 419 



N.W. and S.W 344 



S.W. and S.E 456 



We see by these results that the vane passes more rapidly 

 over from S.E. to N.E., and from N.W. to S.W., than from 

 N.E. to N.W. and S.W. and S.E. 



The relative frequency of the winds affords a means to 

 arrive at the same conclusion, that the quadrants between 

 N.E. and N.W. ; S.W. and S.E. are the critical quadrants, 

 i.e., the contesting field of the alternating currents. 



The following numbers express the relative values of the 



