STELLAR PHOTOGRAPHY. 



219 



by less than a tenth of a magnitude. It is doubtful if this degree of accuracy can 

 be attained by any other photometric process hitherto employed. In no case does 

 a residual exceed three tenths of a magnitude, and in one case only do the meas- 

 ures of the same star differ from one another by as much as six tenths of a 

 magnitude. The greater portion of these stars are too faint to be contained in 

 existing catalogues. Their positions have not yet been determined from the photo- 

 graphs. A full publication of their magnitudes does not therefore seem desirable 

 in the present Memoir. As examples, the 38 stars enumerated in the Durchmuste- 

 rimg as belonging to this region have been selected from the entire list of 117 

 stars, and their measurements are given in Table VI. The successive columns give 

 the Durchmusterung numbers, the photographic brightness of the trail, and the 

 residuals from the mean expressed in tenths of a magnitude, negative residuals 

 being indicated by Italics. In order to make the magnitudes correspond with 

 those of equatorial stars giving trails of equal intensity, each of the original read- 

 ings has been diminished by three magnitudes. By means of Table II. and the 

 formulas given on page 190, a correction has been applied for the declination of 



TABLE VI. 



