172 DE. S. CHAPMAN ON THE LUNAE DIUENAL MAGNETIC VAEIATION, 



TABLE II. Eatio of Mean Semi-amplitudes of the Lunar Semi-diurnal Variation of 

 Terrestrial Magnetism, during a number of half months centred at Perigee and 

 Apogee respectively. 



(a) Declination West. 



(c) Vertical Force. 



