MOUNT WILSON SOLAR OBSERVATORY. 1 57 



PUBLICATIONS. 



The following papers have been published in the Astrophysical Journal and 

 reprinted as Contributions from the Mount Wilson Solar Observatory : 



No. 20. Spectroscopic observations of the rotation of the sun, by Walter S. Adams. 

 No. 21. Sun-spot bands which appear in the spectrum of a calcium arc burning in the 



presence of hydrogen, by Charles M. Olmsted. 

 No. 22. Preliminary catalogue of lines affected in sun-spots, region X 4000 to X 4500, by 



Walter S. Adams. 

 No. 23. The tower telescope of the Mount Wilson Solar Observatory, by George E. 



Hale. 

 No. 24. Preliminary note on the rotation of the sun as determined from the displace- 

 ments of the hydrogen lines, by Walter S. Adams. 

 No. 25. Preliminary note on the rotation of the sun as determined from the motions of 



the hydrogen flocculi, by George E. Hale. 

 No. 26. Solar vortices, by George E. Hale. 

 No. 27. The Pasadena laboratory of the Mount Wilson Solar Observatory, by George E. 



Hale. 

 No. 28. An electric furnace for spectroscopic investigations, with results for the spectra 



of titanium and vanadium, by Arthur S. King. 

 No. 29. Anomalous refraction phenomena investigated with the spectroheliograph, by 



W. H. Julius. 



The annual report of the Director was reprinted from the Year Book of the 

 Institution and distributed with the Contributions. 



