MOUNT WILSON SOLAR OBSERVATORY. 243 



(21) The discussion has brought out many new facts relating to the 

 enhanced hues in the chromosphere. 



(22) Five photographs of Hind's Variable Nebula in Taurus indicate 

 no changes which may not be attributed to differences in the quality 

 of the plates. 



(23) The object N. G. C. 6760, described as a variable nebula, has 

 been found to be a star-cluster showing no traces of nebulosity. 



(24) The first complete determinations of stellar parallax with the 

 80-foot Cassegrain combination of the 60-inch reflector are very 

 satisfactory. 



(25) The measurement of the magnitudes of some 600 stars near the 

 North Pole establishes the photographic scale from the second to the 

 twentieth magnitude. 



(26) As previously found, the magnitudes are in close agreement 

 with the Harvard results for the interval 10.5-15.5, but there are 

 divergences for both bright and faint stars. 



(27) A determination of the photo visual scale for magnitudes 2 to 17.5 

 has been made. 



(28) A comparison of photographic and photovisual magnitudes 

 shows that the minimum color index of the whitest stars increases with 

 increasing magnitude, indicating that the fainter stars are redder than 

 the brighter ones. 



(29) A determination of the photographic and photovisual light 

 curves of the cluster-type variable star RS Bootis indicates a marked 

 change of color with magnitude, in harmony with observations of a 

 simultaneous change in spectrum. 



(30) The total number of constant-velocity stars for which radial 

 velocities have been determined is now 545, an increase of 173 during 

 the year. 



(31) The velocities of 100 parallax stars published since the last 

 report are of special interest. Twenty of these (corrected for the sun's 

 motion) exceed 50 km. and 6 exceed 100 km., the highest being 319 km. 



(32) Two A-type stars of high constant velocity (over 100 km.) have 

 been found. 



(33) Several pairs of optical double stars are indicated by their equal 

 velocities to be physically connected. 



(34) The star 0. Arg. S. 14320 is found to have the enormous velocity 

 in space of 577 km. per second. 



(35) There have been 16 new spectroscopic binaries discovered, 

 making the total number 115. 



(36) Comparative photographs on the same plate of the spectra of 

 near and distant stars show that the latter are, in general, much fainter 

 in the violet. 



(37). Photometric measures of 151 photographs of stellar spectra con- 

 firm this result, and show that the amount of the effect depends upon 

 the spectral type, being twice as great for K0-K4 stars as for F0-F9 stars. 



