484 



Royal Society , 



observations of a single year with the degree of symmetry shown in 

 Table II., we may safely conclude that the observations themselves 

 are worthy of the labour bestowed in eliciting their results. In this 

 view the Hobarton observations prove themselves to have been not 

 only a faithful, but also an extremely careful series, highly creditable 

 to Captain Kay, R.N., and to the Naval Officers who with him and 

 their Civil Assistant Mr. Jeffery, maintained for so many years the 

 laborious and monotonous duty of hourly observation. 



Table III. exhibits the separate results in each of the three years 

 at Kew, as well as their mean. 

 Table III. — Lunar-diurnal Variation at Kew in the years 1858, 



1859, and 1860 ; omitting disturbed observations differing 3'*3 



from their final normals. 



Lunar 

 Hours. 



Year ending December 31. 



Means. 



Lunar 

 Hours. 











1858. 



1859. 



1860. 











-'6-0 



+ "0-6 



-12-6 



- "6-0 







1 



-14-4 



- 7-2 



-12-6 



-11-4 



1 



2 



-10-8 



- 9-6 



- 5-4 



- 86 



2 



3 



- 7-8 



- 4-2 



- 30 



- 5-0 



3 



4 



- 30 



- 4-2 



- 2-4 



- 3-2 



4 



5 



+ 5-4 



- 6-6 



+ 5-4 



+ 1-4 



5 



6 



+ 2-0 



+ 1-2 



+ 3-0 



+ 5-4 



6 



7 



+ 9-0 



+ 4-2 



+ 9-6 



+ 7-6 



7 



8 



+ 19-6 



+ 8-4 



+ 7-8 



+ 8-6 



8 



9 



+ 7-2 



+ 6-6 



- 0-9 



+ 4-3 



9 



10 



+ 3-0 



+ 7-2 



- 1-8 



4- 2-8 



10 



11 



- 3-6 



- 1-2 



- 4-2 



- 30 



11 



12 



- 4-8 



- 90 



-180 



-10-6 



12 



13 



- 3-0 



-13-2 



-15-0 



-10-4 



13 



14 



- 3-0 



- 8-4 



- 9-6 



- 70 



14 



15 



- 7-2 



- 3-6 



+ 4-2 



- 2-2 



15 



16 



+ 3-0 



+ 3-6 



+ 7'8 



+ 4-8 



10 



17 



+ 7-8 



+ 9-6 



+13-8 



-M0-4 



17 



18 



+ 7-8 



+14-4 



+ 17-4 



+ 13-2 



18 



19 



+ 4-8 



+ 18-0 



+ 15-0 



+ 12-6 



19 



20 



+ 3-0 



+ 12-6 



-f- 6-0 



+ 7-2 



20 



21 



- 2-4 



+ 18-6 



+ 2-4 



+ 6-2 



21 



22 



- 7-8 



+ 9-6 



- 3-0 



- 0-4 



22 



23 



- 60 



+ 5-4 



- 3-6 



- 1-4 



23 



In conclusion, it may be useful to call the attention of the Societv, 

 and of those Fellows in particular who interest themselves in tracing 

 up the phenomena of nature to their physical causes, to the assem- 

 blage of facts which are now available for such inquiries, in a branch 

 of magnetical science which may not inappropriately be called 

 celestial magnetism. In the introductory discussion prefixed to the 

 2nd volume of the St. Helena Magnetical Observations, p. cxliv to 

 cxlviii, the lunar-diurnal variation is given for each of the three 

 magnetic elements, the Declination, the Dip, and the Intensity of the 

 force, at the four stations of Toronto, St. Helena, the Cape of Good 

 Hope and Hobarton, and for the Declination at two additional stations 

 Kew and Pekin. The variations are given both in formulas and in 



