1877.] 



Range of Magnetic Declination. 



117 



lagging behind the other in point of time, as might be expected from 

 art. 6. 



13. Xext with regard to the second configuration (the solar period of 

 Mercury), the results are so decided that half the declination observations 

 are sufficient to give a tolerably good value. This will be seen from the 

 following Table : — 



Taele IX. — Period of Mercury about the Sun (in all 65 sets : 

 O 3 denotes Perihelion). 





O 









O 



First half. 



Second half. 



Whole series. 



Between 



and 



30 



+ 217 



+ 212 



+ 429 



j> 



30 



55 



60 



+ 153 



+ 280 



+ 433 



»» 



60 



55 



90 



- 3 



+ 259 



+ 256 



n 



90 



55 



120 



—168 



+ 173 



+ 5 



55 



120 



55 



150 ' 



-281 



+ 1 



-280 



55 



150 



55 



180 * 



-276 



-163 



-439 



55 



180 



55 



210 



-151. 



-262 



-413 



55 



210 



55 



240 



. — 5 



-274 



-279 



55 



240 



55 



270 



+ 73. 



-213 



-140 



55 



270 



55 



300 



+ 114 



-101 



+ 13 



55 



300 



55 



330 



+ 145 



+ 13 



+ 153 



55 



330 



55 



360 



+ 181 



+ 97 



+ 278 



In Pigs. y. and VI. the supposed inequalities due to this period are 

 compared together for spotted solar area and declination-range. It will 

 be observed that the latter lags visibly behind the former in point of 

 time. . . . . 



14. Let us, in the last place, consider the period of the conjunction of 

 Jupiter and Mercury. In this case, as in the previous one, the inequality 

 is so well marked that the observations may be split into two series ; this 

 will be seen from the following Table : — 



Taele X. — Period of Conjunction of Mercury and Jupiter 

 (in all 63 sets : 0° denotes conjunction). 





O 





First half. 



Second half. 



Whole sen 



Between 







and 30 



+ 198 



+ 435 



+ 633 



55 



30 



„ 60 



+ 236 



+ 523 



+ 759 



55 



60 



„ 90 



+ 225 



+ 427 



+ 652 



» 



90 



„ 120 



+ 119 



+ 209 



+ 328 



55 



120 



5, 150 



46 



- 73 



-119 



55 



150 



„ 180 



-185 



-319 



-504 



55 



180 



„ 210 



-251 



-427 



-673 



• » 



210 



„ 240 



-230 



-447 



-677 



55 



240 



„ 270 



-157 



-391 



-543 



55 



270 



„ 300 



- 91 



-231 



-322 



55 



300 



„ 330 







- io 



- 10 



55 



330 



„ 360 



+118 



+ 225 



+ 343 



