42 CARNEGIE INSTITUTION 



In addition to the undertakings we have already enumerated as 

 offering a definite field of great usefulness for the proposed Southern 

 Observatory, there are others which, in the judgment of many 

 astronomers of high standing, deserve a prominent place in this 

 enumeration. The following list briefly recapitulates some of 

 these. 



(7) Astrophysical Researches. 



Should a large reflector be provided for the observatory in con- 

 nection with (4) it could also be utilized with advantage for certain 

 photographic and astrophysical researches of great importance to 

 the advance of science. Among these are : 



(a) Spectroscopic researches upon red and variable stars to sup- 

 plement similar researches in the northern hemisphere. 



(3) Photography of nebulae in order to make the record of 

 similar works complete for the entire sky. 



(f) Spectroscopic examination of the nebulae for the purpose 

 of ascertaining their motions in the line of sight, as well 

 as in the interest of inquiries into their physical nature. 



These and similar works are named as supplementary to that 

 mentioned under (4), not to be carried on to the detriment of the 

 latter. 



(8) The Astrographic Chart. 



Allusion has already been made to the labors upon the ' ' Carte du 

 Ciel," or Astrographic Chart. Director lyoewy, president of the 

 Astrographic Congress, informs us that there is a vacancy in one of 

 the zones ; and he states that the services of the Carnegie Institu- 

 tion would be very acceptable in filling the vacant place. There is 

 no question of the importance of this great project for securing a 

 photographic representation of the entire sky at the present epoch. 

 The work has already progressed so far that its ultimate success is 

 now practically assured. It would be most unfortunate should the 

 completion of one or two sections be delayed far beyond the com- 

 pletion of all the others, thus destro5dng the unity of epoch that is 

 so desirable in all such works. This work requires the use of a thir- 

 teen inch photographic telescope of a special type. This instrument 

 would not be very costly. The services of two observers and of a 

 small corps of measurers and computers would be required during 

 about eight years. We think that the feasibility of undertaking 



