1878.] 



Magnetic Declination at Prague. 



395 



Table VIII. — Period of Conjunction of Mercury and Jupiter (in all 

 150 sets, 0° denotes Conjunction). 





O 



o 



First half. 



Second half. 



Whole seri 



Between 



and 



30 



+ 47 



+ 775 



+ 822 



?j 



30 „ 



60 



-237 



+ 217 



- 20 



55 



60 „ 



90 



-402 



-358 



- 760 



55 



90 „ 



120 



-541 



-738 



-1279 



55 



120 „ 



150 



-583 



-740 



-1323 



» 



150 „. 



180 



— 512 



—402 



— 914 



55 



180 „ 



210 



-328 



- 66 



- 394 



55 



210 „ 



240 



+ 21 



+ 1 



+ 22 



55 



240 „ 



270 



+ 435 



+ 90 



+ 525 



55 



270 „ 



300 . 



+ 636 



+ 421 



+ 1057 



)J 



300 „ 



330 



+ 496 



+ 686 



+ 1182 



55 



330 „ 



360 



+ 300 



+ 885 



+ 1185 



Here, as before, we have a very considerable likeness between the 

 results derived from the two halves, while the whole is very similar to 

 the corresponding period derived from the Kew series or from that of 

 Trevandrum. 



9. Let us now try to combine together the planetary periods derived 

 from the three observatories — Kew, Trevandrum, and Prague — giving 

 equal value to the results of Kew and Prague, and half value to those 

 of Trevandrum. 



We thus obtain the following values of a single period, the unit being 

 as before, one thousandth of the whole mean range : — 



Table IX. — Mean Magnetic Result from the various Observatories. 



Venus and Mercury. 





O 







Kew. 



Prague. 



Mean. 



Between 







and 



30 



+ 4-95 



+ 7-45 



+ 6-20 



55 



30 



55 



60 



+ 0-59 



-1-82 



-0-61 



55 



60 



55 



90 



—5 -03 



-5 -88 



-5-45 



55 



90 



55 



120 



-5-31 



-1 -06 



-3 -18 



55 



120 



55 



150 



-2-38 



+ 3-34 



+ 0-48 



55 



150 



55 



180 



-1-51 



+ 0-98 



-0-26 



5J 



180 



55 



210 



-1 -io 



-0-33 



-0 71 



55 



210 



55 



240 



+ 0-33 



+ 1 -14 



+ 0-73 



55 



240 



>5 



270 



+ 0-66 



-3-20 



-1 27 



5> 



270 



55 



300 



-1 33 



-8-66 



-4-99 



55 



300 



55 



330 



-1 -26 



-2 32 



-1-79 



J) 



330 



55 



360 



+ 3-05 



+ 8-47 



+ 5 76 



VOL. XXVII. 2 D 



