Sun-spots and Terrestrial Phenomena. 



261 



in paragraph 3, thus obtaining a table of differences (48 to each year) 

 to be re-arranged successive] y in three new tables, in lines correspond- 

 ing to the respective periods — one line to each period. 



The dates of conjunction and perihelion respectively having been 

 taken from the "Nautical Almanac," the differences were divided into 

 sets in such a manner that the mean dates of the first and last differ- 

 ences of each set never encroached on the preceding or following 

 period. The number of differences in a set were, for the periods (/3) 

 and (7), always either twelve or eleven, and when only eleven they 

 were increased to twelve by repeating either the last difference of the 

 preceding set or the first difference of the following set, whichever 

 was the nearer in point of time to the intervening period. The period 

 (a) is so variable that the number of differences in a set varied from 

 seventeen to twenty-one ; when seventeen they were increased to nine- 

 teen by repeating the preceding and following differences; when 

 eighteen they were increased to nineteen in the same manner as eleven 

 were increased to twelve in the case just described ; when twenty the 

 two first or two last numbers were replaced by the mean of them — 

 whichever was furthest in point of time from the middle of the inter- 

 vening period ; and when twenty-one the two first and the two last 

 differences were both replaced by their mean values. 



The results (the algebraical sums of the columns) given by the 

 several periods are as follows : — 



Table IV. — Period of Conjunction of Venus and Mercury (0° denotes 



Conjunction). 









62 periods. 



First 31 periods. 



Last 31 periods. 



Between 0° 



and (sj^)° 



+ 839 



+ 637 



+ 202 





(¥ 9 -) 



55 2(Vs£) 



+ 741 



+ 453 



+ 288 



55 



2(^% -) 



3, 8(W) 



-221 



- 87 



-134 





3(W) 



5, MW) 



-545 



-331 



-214 



33 



4(W) 



3, B(W) 



-564 



-595 



+ 31 



33 



5(W) 



3, 6(W) 



-267 



-604 



+ 337 



33 



6(W) 



33 1(W) 



+ 448 



-261 



+ 709 



35 



„ 8(^1) 



+ 398 



+ 46 



+ 352 



33 



8(W) 



,3 HW) 



+ 51 



+ 130 



- 79 



53 



9 (W) 



3, io(w) 



-700 



-347 



-353 



33 



10 (^%f-) 



33 11 (W) 



-311 



+ 120 



-431 





11 (W) 



„ 12(4#) 



+ 252 



+ 388 



-136 



35 



18 (W) 



3, 13 (^m 



+ 637 



+ 390 



+ 247 



3> 



1S{\% -) 





+ 855 



+ 484 



+ 371 





14 



33 1B(-W) 



-264 



-261 



- 3 







3, 16 (W) 



-976 



-516 



-460 





16(W) 



„ 17(W) 



-426 



- 91 



-335 







„ 18 (W) 



+ 81 



+ 282 



-201 





18(W) 



33 W) 



+ 196 



+ 234 



- 38 



