.340 Di;. C. CHIvEE: ANALYSES OF RESULTS FKUM THE KEW MAGNETOGRArHS 
Year .... 
1890. 
1891. 
1892. 
1893. 
1894. 
1895. 
1896. 
H. 
-47 
+ -7 
V. 
+ 727 
+ 937 
+ 967 
+ 577 
+ 577 
+ 137 
1. 
— 
+ 2'-0 
+ 2'-6 
+ 2'-7 
+ r-6 
+ l'-6 
+ 0'-4 
Tir as can he judged, no correction is necessary for personal equation in the 
ohservations. During the whole period dealt with, the magnetic work has been 
under the cliarge of the Dhief Assistant, Mr. T. W. Bakeu, who has himself observed 
on the great majority of occasions. During 1891 to 1893 Mr. K. S. Whipple 
observed pretty frequently, and since then, during Mr. Baker’s holidays, the 
horizontal force observations have been mainly taken by myself, and the declination 
and inclination (jbservati(ms by Mr. Y¥. Boxall. No certain difference has, however, 
manifested itself between the several observers. 
§ 6. The mean annual values of the elements as corrected are given in Table II., 
and the corresponding secular changes appear in Table III. The values of N, M", 
and T were calculated from those of D, H, and I by the formulae 
N = H cos 1), W = H sin D, T = H .sec I. 
The action of the vertical-force magnetograph during the last two or three months 
of 1890 was not considered satisfactory at the time, and the corresponding results 
were discarded. Thus 1891 was the first year for which satisfactory mean annual 
values were obtainable for V and I. Tlie mean values at the foot of Table II. are 
thus calculated for 10 years only in the case of V, T, and I, as against 11 years in the 
other cases. These mean values are wanted later, they do not possess any immediate 
significance in connection with secular change. 
In Table III. I have added mean values of the secular changes at Parc St. Maur 
and Potsdam, for comparison with the mean changes at Kew. The Parc St. Maur 
data are from publications by Moureaux.^ As data for 1900 were not available the 
means in this case are for the period 1890 to 1899 for D and H, and the period 1891 
to 1899 for I and il’he Potsdam data are from a paper by Eschexhagex ;t they 
refer to exactly the same periods as the corresponding Kew data. 
* • Ann. du Bineau Central Meteorologitjue de France,’ 181*7, “ Memuires,” p. B. 65. 
t ‘ Ann. der Physik,’ vol. 6, 1901, p. 424. 
