Magnetic Declination and Horizontal Force and Solar Spots. 77 



Table IV. Monthly Mean Diurnal Range of Declination and Hori- 

 zontal Force as determined from the observations on five selected 

 quiet days in each month. 





Table Y. Annual Means of the Monthly Mean Diurnal Range of 

 Declination and Horizontal Force as determined from the obser- 

 vations on five selected quiet days in each month. (As in Table II, 

 each number represents an annual mean of which the month itself 

 is the middle point.) 



