444 LIEUT.-GENEEAL SABINE ON THE BESTTLTS OP THE 



the same methods of investigation have been pursued, though with series of observations 

 of shorter continuance, we find an approximation to the results at Kew and Hobarton 

 far too close to be accidental. Everywhere there is evidence of a similar double pro- 

 gression in the lunar day with branches of nearly equal duration. The extreme deflec- 

 tions which we have noted as occurring at Kew and Hobarton at the lunar hours of 1 

 and 13 (easterly at Kew and westerly at Hobarton), are recorded as occurring at Toronto 

 at O"" and 12'', at Philadelphia at 1'' and IS^, and at Pekin at 23'» and ll^ all being maxima 

 of easterly deflection; and at the Cape of Good Hope (a westerly maximum, as the 

 Cape is in the southern hemisphere) at 23'' and ll**. In like manner the hours which 

 characterize the opposite extremes at Kew and Toronto to those just noticed, viz., the 

 westerly at Kew and easterly at Hobarton, which are at 7** and 19'', are recorded as 

 occurring at Toronto at 6'' and 18'', at Philadelphia at 7'' and IQ*", at Pekin at 5''-5 and 

 17''-5, and at the Cape of Good Hope at 5''-5 and 17''-5. 



Some difference, in the time of the occurrence of a particular phase of the variation, 

 as well as in its amount, we should be prepared to find in different localities, due to 

 differences in their position on the surface of the magnetic sphere ; but with this allow- 

 ance there is a systematic consistency in the particulars which have been cited, which, 

 even in this, the infancy of the inquiry, promises to conduct those who will pursue it to 

 the recognition of one of those laws of general application which characterize the ope- 

 ration of great cosmical forces, 



A coi-responding accordance in the phenomena of the lunar influence on the Inclina- 

 tion and on the Total Force might easily be shown, even from the very brief record which 

 we as yet possess from the very few stations at which the phenomena have been made 

 the objects of investigation, carried on with suitable instruments and with suitable 

 methods of reduction. The conclusions from them are indeed somewhat less precise 

 than in the case of the Declination, because the conditions of the problem are necessarily 

 more complex; but they have the same general character and bearing in all material 

 respects ; and enough has already been stated to establish the general fact of the exist- 

 ence and systematic action of the moon's magnetic influence at the surface of our 

 globe, and to show that its phenomena are quite within the reach of properly directed 

 research ; and that they are assuredly well worthy of the attention of those who occupy 

 themselves in the pursuits of inductive philosophy. 



To establish on a satisfactory basis the existence of a difference in the amount of the 

 lunar-diurnal variation at the times when the moon is nearest to or furthest from the 

 earth, would probably require many more years of observation than have hitherto been 

 given to the subject at Kew. But it may not be superfluous to state that in the Vertical 

 Force, which is the only one of the elements in which the extreme deflections at the 

 turning hours on the two days preceding and the two days subsequent to the epochs of 

 perigee and apogee have hitherto been separately examined, the deflections are decidedly 

 greater in their mean amount in perigee than in apogee ; which is so far encouraging 

 towards a continuance of the examination in future years. 



