220 



STELLAR PHOTOGRAPHY. 



the star. The result, which is given in the fourth column, shows the actual photo- 

 graphic brightness of these stars. The fifth column gives the Durchmusterung mag- 

 nitude, and the final column gives the residual found by subtracting the photographic 

 from the DM. magnitudes, after reducing the scale of the latter to that of the former. 

 Positive residuals indicate stars of a bluish color, and negative residuals those of a 

 reddish color, provided no errors are present. 



No. 



or DM. +89° 5, is shown to consist of two equal stars, whose combined 



o 



ht would equal that of a star of the magnitude 10.6, and give a resid 



the last column. Nos. 14 and 15 are so nearly in the same declination that then 

 trails coalesce, although separate at the ends. Their combined light was originally 

 measured, and the measures given were made subsequently. No. 27 was originally 

 omitted, since by precession it is now outside of the limit of one degree north polar 

 distance. 



The greater portion of the stars in Table VI. differ but little in brightness. 

 Accordingly, measurements were made of the polar stars proposed as standards of 



TABLE VII. 



Desig. 



269 



88° 112 



88° 37 



a 1880 



h. m. 



18 11 

 6 44 



19 44 

 51 



2 28 

 17 50 

 19 28 



19 

 13 23 

 19 30 

 19 30 



23 10 



18 30 

 9 10 



10 



81880. 



88 40 

 86 37 



88 57 

 88 23 



88 36 



89 36 

 89 48 

 89 54 

 89 45 

 89 49 

 89 54 

 89 55 

 89 50 

 89 53 

 89 57 

 89 54 

 89 58 

 89 58 

 89 58 

 89 57 



Trail . 



1.17 

 2.40 

 3.43 



3.08 

 3.97 

 3.37 



3.67 

 3.87 

 5.13 

 6.00 

 5.93 

 6.23 

 6.13 



6.60 



Resid 



210 



2ii 

 in 



in 



001 



111 



100 



111 

 111 



201 

 000 



111 



212 



lii 



20i 



Photog. 

 Magi i. 



10.4 



10.8 

 10.0 



11.1 

 12.9 



13.0 

 13.2 



12.7 



14.2 



Pliotora. 

 Magn. 



10.5 

 10.5 

 10.0 



12.2 

 12.4 

 12.8 

 13.2 

 13.3 

 14.0 

 14.0 



14.8 

 14.8 

 15.7 



Res 



