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PROCEEDINGS OF THE AMERICAN ACADEMY 



The successive column,s give the Flamsteed immbers, the photometric 

 magnitudes, and the magnitudes according to Sir William Ilerschel. 

 These have been derived from a discussion of all six catalogues of 

 Ilerschel. They have a special value for the present purpose, since 

 they indicate the brightness of these stars at the time the observations 

 now under consideration were made. The fourth column gives the 

 nuignitude according to the Uranometria Argentina. The magni- 

 tude of 19, 8 LibrcB, according to each of these scales is inserted in 

 brackets. 



TABLE IV. 



The scale of the Uranometria Argentina differs two or three tenths 

 of a magnitude from that of the photometer for stars of the fifth and 

 sixth magnitude. For the stars used in this comparison the difference 

 amounts to four tenths of a magnitude. Applying this correction, 

 the results become more readily comparable without affecting the con- 

 clusions derived from them. In Table V. the brightness of 8 at the 

 time of the various observations, and at maximum and minimum, as 

 stated in the first column, is compared. The following columns give 

 the mairnitude derived in Table IV. from the three authorities, after 

 applying a correction of four tenths of a magnitude to the Urano- 

 metria Argentina. The last column gives a mean value which may 

 be employed, since all the observations have been reduced to liie 

 same scale. 



T.VBLE V. 



