382 



PROCEEDINGS OF THE AMERICAN ACADEMY 



TABLE YL — Light Curve of fi Persei. 



It does not seem to be practicable to obtain at present more accurate 

 values from the observations of Dr. Schonfeld, on account of the un- 

 certainty in the value of a grade. The observations themselves are 

 much more precise, and determine the time of minimum, as has been 

 shown above, with an accuracy nearly equal to that of the photometric 

 measures. Even if more accurate measures of the comparison stars 

 should be made, we should still be in doubt whether to assume that g 

 is constant, or that the reduction should be made, as in the last column, 

 by a curve. From the residuals it a[)pfars that the various deduced 

 values differ from each other more than they differ from the photo- 

 metric measures. It accordingly appears scarcely safe to correct the 

 latter by the former. Tlie three values of the minimum correspond- 

 ing to the last three columns are 1.72, 1.56, and 1.65 magnitudes, their 

 mean agreeing exactly with the photometric measure of 1.64. 



It is to be noticed that the. value of (/ = 0.029 is confirmed by 

 the photometric measure of ^ Persei, since the residuals are less than 

 when g is taken equal to 0.025. A wholly inde[)endent test of the 

 accuracy of the meridian photometer measures is thus afforded. Since 



