P. E. Chase on influence of Gravity on Magnetic Declination. 87 
Tametolre.m lemto7 aM. 
Northern zones, S.E 
Southern “ 
N.E. N.W 
the northern extremity. RRS 
Substituting these declination values for the current-deviations 
to which they correspond, the almost precise accordance of theory 
and observation in*the prominent features of the normal varia- 
a of declination, may be seen by a reference to the following 
table: 
Daily maximum,’ Easterly. Westerly. | 
Half-yearly “ April to Sept.? } Easterly. Westerly.|Morning.|Evening. 
eee ORS ly. | Mean. | Mean. 
Westerly. Easterly. an. | Stationary. 
Theoretical, - - = = - | 7 AM. lem. | 10am. | 4PM. |7P.M.tolam. 
Observed [I to ¥i;° es 6-8 “ Ea 9} “ 5 « gs“ «3 e 
Gen. Sabine, in speaking of the opposition of the annual and 
semi-annual curves (St. Hel. Obs., 2, exix), says, “ these remark- 
able systematic dissimilarities may be regarded as sufficient m- 
dications of a difference in the mode of operation of the solar in- 
fluence in the two cases.” I am not aware that any attempt has 
* In the northern zones. ? Over the whole earth. aa 
* The bracketed references are to the numbered quotations from the Girard Col 
