I04 CARNEGIE INSTITUTION 



accomplish work urgently needed for the progress of astronomy, for 

 which provision can not equally well be made elsewhere. 



This subject is so important and presents so many points of nov- 

 elty that it would be impossible for your Committee during its brief 

 remaining tenure of office to give it consideration adequate for the 

 presentation even of a preliminary working plan. We have con- 

 tented ourselves, therefore, with the foregoing general suggestions, 

 and we would urge upon the Trustees of the Carnegie Institution 

 the importance of a full and careful investigation by means of a 

 commission specially appointed for that purpose. 



Edward C. Pickering, Chairman, 



S. P. L ANGLE Y, 



Simon Newcomb, 

 George E. Hale, 

 IvEwis Boss, 



Committee. 

 October 21, 1902. 



Sub-Appendix of Appendix A to Report of Committee 



ON Astronomy. 



PROPOSAI. FOR A DISTINCTLY SOLAR OBSERVATORY. 



October 20, 1902. 

 Professor George E. Hale : 



I have been asked by you for information in some detail regard- 

 ing the scheme of observations, installation of buildings, and cost 

 of equipment of a solar subtropical observatory for studying the 

 Solar Constant and allied problems at a great altitude, which was 

 proposed in answer to a letter from Mr. Walcott. 



I have just returned from Europe and am unprepared to give any 

 exact estimate, but will in the little time at my disposal indicate in 

 general terms what is needed. I have for this purpose taken a list 

 of apparatus actually in use at the Astrophysical Observatory and 

 extended by Mr. Charles G. Abbot, the aid acting in charge, to 

 what might be desired in the proposed installation, as a basis for 

 my estimate of cost. 



In my mind the essential idea for the solar observatory is to have 

 two adjacent solar installations in immediate sight of each other ; 

 one at a certain considerable altitude, the other at the very highest 

 altitude at which an observer can work, perhaps even only with 



