244 COMMANDER L. W. P. CHETWYND: RESULTS OF MAGNETIC OBSERVATIONS 



increase has, since the year 1898, been diminishing, that this annual increase is at 

 present very small, and may shortly become an annual decrease. Thus, if AH 

 represent the difference of the values of Horizontal Force for successive years, AH has 

 been positive, but has since the year 1898 diminished in numerical value. 



AH is at present very small and may shortly change from being + to being . 



27. The Inclination-change curve, fig. 4, indicates that the amount of the annual 

 decrease has been, and still is, diminishing, and that its present value is 1'. Thus, 

 if A0 represents the difference of the values of Inclination for successive years, A0 has 

 been, and still is, negative, but has diminished in numerical value until it is now 1'. 



. , . _j i 1 i ; i 1 > - 



1889 .10 91 sa 93 94 93 96 37 S3 99 I900 Ol 0! (X5 04 K> 06 07 08 



Fig. 1. Curves of mean annual decrease of Declination at Ke\v, Greenwich, and Stonyhurst 



(derived from quinquennial means). 



1889 90 91 9 93 9* 95 86 97 98 99 1900 01 OZ 03 04 05 



Fig. 2. Curve of mean annual decrease of Declination at Kew 

 (derived from quinquennial means). 



06 07 



03 



