OBSERVATIONS COMPARED WITH EPHEMERIS. 



CC1X 



VENUS II. 



Computation for Cracow Meridian Observations. 



8. SOLAR PARALLAX FROM CORRESPONDENT OBSERVATIONS. 



The fewness and insufficiency of the correspondent observations have already been shown and 

 commented upon. It is nevertheless proper to deduce such resultant values as they afford, and 

 this the preceding computations now enable us readily to do. 



The comparisons in these cases having been made with the same star and nearly at the same 

 time, the corrections of the ephemeris and of the semidiameter may be regarded as constant 

 for the interval which may have elapsed between the northern and the southern observation. The 

 paucity of material renders any attempts to eliminate the influence of irradiation or of personal 

 equation altogether futile, and the formula thus assumes a very simple shape. 



The comparison of the planet with a fixed star gives the equation 



3 d=3 d J<Jr k* *Am if + t + q 



or Dm = 3 d + (46 a ) r 

 in which the notation of 3 is retained, p a being substitued for k *r o , the parallax as computed 

 with the adopted Enckian value. 



The results of the correspondent observations thus computed are appended, and arranged in a 

 form which will explain itself. The northern observations are first given, then the southern 

 ones, and lastly, the values deduced from the combination of the two, together with the determi- 

 nation of a- from the equation 



8= (k, - k,) iw = WDj (Am t - Am,) (r, - r.) + (ft ft) 



Z 3 



