APPENDIX II 



SUMMARY OF SPECTROBOLOMETRIC WORK ON MOUNT WIL- 

 SON DURING MR. ANGSTROM'S INVESTIGATIONS 



Bv C. G. Abbot 



Table 16, similar in form to tables 35 and 36 of Vol. Ill of the 

 Annals of the Astrophysical Observatory of the Smithsonian Institution, 

 contains a summary of all Mount Wilson spectrobolometric observations 

 obtained by Mr. Aldrich, with accompanying" measurements and reductions, 

 for days in which Mr. Angstrom obtained observations in California in 1913. 

 The final column is of interest in connection with the pyrheliometric observa- 

 tions on Mount Whitney, given in Appendix III. The third column contains 

 spectroscopic determinations by Mr. Fowle of the total depth of precipitable 

 water existing as vapor above the observing station at Mount Wilson (latitude 

 34 12' 55" N., longitude 118° 03' 34" W., elevation 1,727 meters or 5,665 feet). 

 The letters given under " grade " have the following meanings : vp, very 

 poor ; p, poor ; g, good ; vg, very good ; e, excellent. All observations were 

 made between 6 and 10 o'clock in the morning except those of August 8, 

 which were made between 2 and 6 o'clock in the afternoon. For a discussion 

 of the methods and apparatus used the reader is referred to Vol. Ill of the 

 Annals, cited above. 



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