TABLE XIV ===============+==============+======================================= Type | m_{n} – m_{T}| Number ---------------+--------------+--------------------------------------- E0–E3 | 1.64 | (9) E4–E7 | 1.43 | (7) Sa–SBa | 0.97 | (5) 1.27 when N.G.C. 5866 is omitted Sb–SBb | 1.70 | (11) Sc–SBc | 1.76 | (5) 1.19 when N.G.C. 5194 is omitted +--------------+--------------------------------------- Unweighted mean| 1.50 | (37) 1.45 (35) Weighted mean | 1.55 | (37) 1.52 (35) ---------------+--------------+--------------------------------------- TABLE XV Absolute Magnitudes of Nebulae =============+===========+====================== System | M_{T} | M_{S} -------------+-----------+---------------------- Galaxy | | –5.5 M 31 | –17.1 | 6.5 LMC | 17.0 | 8.0 SMC | 16.0 | 5.5 M 33 | 15.1 | 6.5 N.G.C. 6822 | 13.7 | 5.8 M 101 | 13.5 | –6.3 M 32 | –13.3 | +-----------+---------------------- | | –6.3 | | –9.0 = M_{S} – M_{T} +-----------+---------------------- Means | –15.1 | –15.3 Adopted | –15.2 | -------------+-----------+---------------------- In Table XV are listed absolute magnitudes of the entire system and of the brightest stars involved, for the galaxy and the seven nebulae whose distances are known. The data for the Magellanic Clouds are taken from Shapley’s investigations. The absolute magnitudes of the remaining nebulae were derived from Holetschek’s apparent magnitudes and the distances as determined at Mount Wilson, where the stellar magnitudes were also determined. M 32 is generally assumed to be associated with the great spiral M 31, because the radial velocities are nearly equal and are unique in that they are the only large negative velocities that have been found among the extra-galactic nebulae. M 101 has been added to the list on rather weak evidence. The brightest stars involved are slightly brighter than apparent magnitude 17.0, and several variables have been found with magnitudes at maxima fainter than 19.0. Sufficient observations have not yet been accumulated to determine the light-curves of the variables, but from analogy with the other nebulae they are presumed to be Cepheids. On this assumption, both the star counts and the variables lead to a distance of the order of 1.7 times the distance of M 33. The inclusion of M 101 does not change the mean magnitude of the brightest stars involved, but reduces the mean magnitude of the nebulae by 0.2.