116 



Prof. B. Stewart on the Daily 



[Alar. 22, 



differences, slightly equalized, are therefore made to form the ordinate 

 of a curve of which the time is the abscissa, and we may expect to derive 

 from such a curve materials for determining whether there be any 

 inequality in the declination-range due to such configurations. The 

 method employed in plotting this curve will be understood from the fol- 

 lowing example : — 



Table TIL 



Date, 1858. 

 Feb. (3) 



Monthly 

 value. 



1034 



Mar. (0) 



1022 



„ (1) 



1025 



» (2) 



1025 



„ (3) 



988 



April (0) 



952 



» (1) 



910 



12. With regard to the fir 

 conjunction of Venus and Mer 



Three- 

 monthly 

 value. 



. 983 

 . 983 

 . 980 

 . 974 

 . 961 

 . 950 



Difference. 



+ 45 

 + 40 

 + 45 

 + 32 

 + 9 

 - 4 



Final equalized 

 difference, plotted 

 in the curve. 



+43 

 + 42 

 + 38 

 + 21 

 + 2 



st configuration mentioned (the period of 

 cury), these observations embrace 39 periods 

 in all ; and summing up the ordinates of the curve corresponding to each 

 30 degrees of angular separation for the various 39 periods, precisely 

 after the manner employed in the paper on Solar Physics already referred 

 to, we obtain the following result : — 



Table VIII. — Venus and Mercury together (0° denotes conjunction). 



o 



Between 



and 



O 



30 



+ 193 



30 



55 



60 



+ 23 



60 



>» 



90 



-196 



90 



55 



120 



-207 



120 



55 



150 



- 93 



150 



?J 



ISO 



- 59 



180 



>} 



210 



- 43 



210 



?5 



240 



+ 13 



240 



55 



270 



+ 26 



270 



55 



300 



- 52 



300 



»? 



330 



- 49 



330 



JJ 



360 



119 



In Figs. III. and IV. (p. 105) the sun-spot and the declination-curve for 

 this configuration are exhibited together. It will be noticed that there is 

 a very striking likeness between the two, the declination-curve, however. 



