9 6 



VOLUME 4. 



70. The Photographic Magnitude Scale of the North Polar 



Sequence. Frederick II. Scares, 27 pp. 



71. Preliminary Results of an Attempt to Detect the General 



Magnetic Field of the Sun. George E. Hale. 74 pp., 



4 pl. 



72. The Displacement-Curve of the Sun's General Magnetic 



Field. Frederick H. Scares. 27 pp. 



73. A Study of the Relation of Arc and Spark Lines by 



Means of the Tube-Arc. Arthur S.King. 26pp., 2 pl. 



74. Radial Motion in Sun-Spots. II. The Distribution of the 



Elements in the Solar Atmosphere. Charles K. St. 

 John. 51 pp. 



75. Tertiary Standards with the Plane Grating. The Testing 



and Selection of Standards. Second Paper. Charles 

 E. St. John and L. W. Ware. 24 pp. 



76. The Variation with Temperature of the Electric Furnace 



Spectrum of Titanium. Arthur S. King. 27 pp., i pl. 



77. An Application of the Registering Micro-Photometer to 



the Study of Certain Types of Laboratory Spectra. 

 Arthur S. King and Peter Paul Koch. 17 pp. 



78. Note on the Relative Intensity at Different Wave-Lengths 



of the Spectra of Some Stars having Large and Small 

 Proper Motions. Walter S. Adams. 4 pp., i pl. 



79. The Radial Velocities of One Hundred Stars with Measured 



Parallaxes. Waller S. Adams and Arnold Kohlschtitter. 



9 PP- 



80. Photographic Photometry with the 6b-Inch Reflector of 



the Mount Wilson Solar Observatory. Frederick II . 

 Scares. 34 pp. 

 8r. The Color of the Faint Stars. Frederick H. Scares. 9 pp. 



82. On the Individual Parallaxes of the Brighter Galactic 



Helium Stars in the Southern Hemisphere, together 

 with Considerations on the Parallax of Stars in Gen- 

 eral. J. C. Kapteyn. 86 pp., i pl. 



BEGINNING VOLUME 5. 



83. ( )n the Change of Spectrum and Color Index with Distance 



and Absolute Brightness. Present State of the Ques- 

 tion. J. C. Kapteyn. 18 pp. 



84. A Vertical Adaptation of the Rowland Mounting for a Con- 



cave Grating. Arthur S. King. 8 pp., i pl. 



