312 



Royal Society , 



of the magnetic storms, indicated by the observations at the British 

 Colonial Observatories between 1840 and 1850, had led to the antici- 

 pation that the next epoch of maximum of the cycle might take place 

 ill the years 1858-1859. The nearly equal proportions in which the 

 numbers and aggregate values of the larger disturbances took place 

 in 1858 and 1859 are so far in accordance with this view. Should 

 the records of the succeeding years at Kew, made with the same in- 

 struments, and examined by the same method, show decreasing dis- 

 turbance in 1800 and 1861, the precise epoch of the maximum indi- 

 cated by the records of the Kew declinometer will be " the end of 

 1858 or commencement of 1859." 



In Table I. are shown the aggregate values of disturbance in the 

 two years, arranged under the several hours of solar time in which 

 they occurred. They are also divided into the two categories of 

 westerly and easterly deflections, since the experience gained at other 

 stations has now fully established that the westerly and easterly dis- 

 turbance-deflections are characterized in all parts of the globe by 

 distinct and dissimilar laws. The Ratios are also shown which the 

 aggregate values at the different hours, both of the westerly and the 

 easterly deflections, bear to their respective mean values, — or, in other 

 words, to the sums respectively of the westerly and easterly deflec- 

 tions at all the hours, divided by 24, and taken as the respective units. 

 Table I. — Showing the aggregate values of the larger disturbances of 

 the Declination at the different hours of solar time in 1858 and 1859, 

 derived from the Kew Photographs ; with the Ratios of disturbance 

 at the several hours to the mean hourly value taken as the Unit. 



Mean 



astronomi- 

 cal hours. 



Westerly deflections. 



Easterly deflections. 



Mean 



civil 



hours. 



Aggregate values. 

 (Minutes of arc.) 



Ratios. 



Aggregate values. 

 (Minutes of arc.) 



Ratios. 



18 

 19 



20 



21 



22 



23 







I 



2 



3 



4 



5 



G 



7 



8 



9 



10 



11 



12 



13 



14 



15 



16 



17 



553-9 

 549-3 

 4429 

 3701 

 376-9 

 361-8 

 413-7 

 431-1 

 4598 

 5130 

 403-9 

 343-8 

 282-5 

 110-7 

 65-6 

 88-2 

 59-0 

 35-7 

 146-7 

 141-8 

 146-7 

 151-5 

 289-5 

 458-9 



1-85 

 1-83 

 1-48 

 1-23 

 1-26 

 1-21 

 1-38 

 1-44 

 1-53 

 1-71 

 1-35 

 115 

 0-94 

 0-37 

 0-22 

 0-29 

 0-20 

 0-12 

 0-49 

 0-47 

 0-49 

 0-51 

 0-97 

 1-53 



118-9 

 120-9 

 115-2 

 121-2 

 104-6 

 125-8 

 173-0 

 153-3 

 1730 

 108-4 

 141-0 

 164-8 

 2911 

 381-8 

 499-0 

 572-9 

 724-3 

 767-8 

 709-5 

 634-8 

 577-2 

 461-8 

 305-8 

 144-9 



0-37 

 0-38 

 0-36 

 0-38 

 0-33 

 0-39 

 ? 54 

 0-48 

 0-54 

 0-34 

 0-44 

 0-51 

 091 

 119 

 1-56 

 1-79 

 2-25 

 2-38 

 2-21 

 1-98 

 1-80 

 1-45 

 0-95 

 0-45 



6 a.m. 



7 A.M. 



8 A.M. 



9 A.M. 



10 A.M. 



11 A.M. 



Noou. 



1 P.M. 



2 P.M. 



3 P.M. 



4 P.M. 



5 P.M. 



6 P.M. 



7 P.M. 



8 P.M. 



9 P.M. 



10 P.M. 



11 P.M. 



Midnight. 



1 A.M. 



2 A.M. 



3 A.M. 



4 A.M. 



5 A.M. 



Mean hourly value 299-9 = 1-00 



Mean hourly value 320-6 = 1-00 



