MAGNETIC DISTUEBANCES AT KEW. 



285 



" average departure from the mean " is meant the quotient when the arithmetical 

 sum of the 24 hourly differences from the mean for the day is divided by 24. 



Tables VI. and VII. contain the H and V inequalities for individual months of the 

 year based on all the disturbed days. The V inequalities are plotted in the curves 

 of fig. 1. These curves, it is hoped, will carry conviction of the fact that the main 

 features of the monthly inequalities are not accidental. 



?^wt/ rf 



Table VIII. gives the H and V diurnal inequalities for the year and the four seasons, 

 based first on all the disturbed days, then for winter and equinox on the 10 days a 

 month of largest range, and, finally, in the case of V, on the disturbed days of the 

 four years 1892 to 1895 only. In forming the seasonal variations equal weight was 

 allowed to each month, irrespective of the number of days, except in the case of the 



