Local System and Draper Extension 61
the frequency of Class A stars of successive intervals of
brightness.
Figures 5 to 10 give plots of the positions in equatorial
coordinates of stars between magnitudes ten and eleven in
region of the Henry Draper Extension. Coordinates are right ascen-
sion and declination. The heavy curved line represents the galactic
circle.
the Taurus region, which extends over about nine hundred
square degrees and includes sections of several of the neigh-
boring constellations. The course of the galactic circle
through the region is indicated.