396 



Prof. B. Stewart on 



[May 16. 



Period of Mercury. 





o 





O 



Few. 



Trev* 



Prague. 



Mean. 



Between 







and 



30 



+ 



.-/3A 



oO 



+ 3*02 



+ 2 -33 



I A 



+ 4 



18 



jj 



30 



55 



60 



+ o 



DO 



+ 3*91 



— 1 '86 



1. ct 



+ 2 



/0 



M 



60 



55 



90 



i o 



+ o 





+ 6 '16 



— 6 -04 



+ 



.on 



39 



55 



90 



55 



120 



I A 



+ 



• AQ 



Uo 



+ 8 77 



-8 75 



— 1 



71 



55 



120 



55 



150 



A 



— 4 



• 91 



+ 6 -21 



— 7 -47 



— 6 



. A *7 



4/ 



55 



150 



55 



180 



/? 



— O 



/O 



— 5 *19 



—4 -64 



— 5 



. f r> 



5^ 



55 



180 



55 



210 



c 



— D 



•QK 

 OO 



— 15-35 



— 1 -67 



— o 



.oo 



zo 



55 



210 



55 



240 



-4 



•29 



— 15 *23 



+ 1 74 



-4 



•07 



55 



240 



5 5 



270 



-2 



•15 



— 8 14 



+ 5 '07 



-0 



•46 



If 



270 



55 



300 



+ 



•20 



+ 2-39 



+ 6-04 



+ 2 



•97 



55 



300 



55 



330 



+ 2 



•43 



.+ 9-02 



+ 6-20 



+ 5 



•26 



55 



330 



55 



360 



+ 4 



•28 



+ 6-26 



+ 5-88 



+ 5 



•32 















Mercury 



and Jupiter. 









o 





o 



Few. 



Trer. 



Prague. 



Mean. 



Between 







and 



30 



+ 10 



•05 



+ 10 '53 



+ 5 -48 



+ 8 



•32 



55 



30 



j» 



60 



+ 12 



•05 



+ 6 -28 



— 13 



+ 6 



•02 



5? 



60 



55 



90 



+ 10 



•35 



+ 3 -00 



— 5 "07 



+ 2 



•71 



55 



90 



55 



120 



+ 5 



•21 



— 2 -74 



— 8 '53 



-1 



•88 



» 



120 



55 



150 



- 1 



•94 



— 8:93 



— 8 -82 



-6 



•09 



55 



150 



55 



180 



- 8 



•oo 



— 10 -86 



— 6 -09 



-7 



•81 



55 



180 



55 



210 



-10 



•76 



—11 33 



—2 '63 



-7 



•62 



55 



210 



55 



240 



-10 



•76 



— 9'51 



+ -15 



-6 



•15 



55 



240 



55 



270 



- 8 



•70 



Ci .OA 



— 2 84 



+ 3 '50 



— 2 



•65 



55 



270 



55 



300 



- 5 



•11 



+ 5-16 



+ 7-05 



+ 1 



•81 



55 



300 



55 



330 



- 



•16 



+ 9-65 



+ 7-88 



+ 5 



•02 



55 



330 



JJ 



360 



+ 5 



•44 



+ 11 -70 



+ 7-90 



+ 7 



•68 



10. The mean sun-spot results corresponding to these three periods 

 may be derived from the researches of Messrs. De La Rue, Stewart, 

 and Loewy (Phil. Trans., 1870). For a single period they are as follows, 

 the solar unit being one millionth of the sun's visible hemisphere : — 



Table X. 



Mean Solar Results. 



Period of 



Between 



and 



30 



55 



30 „ 



60 



55 



60 „ 



90 



55 



90 „ 



120 



Terms and 

 Mercury. 



+ 18 -61 

 - 1-54 

 -18 -50 

 -26 -17 



Mercury. 



-2 

 -8 



57 

 03 

 (39 

 •53 



Mercury and 

 Jupiter. 



-1 



-2 

 -4 

 -4 



56 

 17 

 07 

 89 



* I take this opportunity of mentioning that a slight error has occurred in my 

 determination of the inequality due to the period of Mercury, as shown by the 

 Trevandrum observations (Proc. Eoy. Soc, February 7, 1878), and that the above is 

 the correct result. 



