REPORT OF COMMITTEE ON SOUTHERN AND 

 SOLAR OBSERVATORIES 



CONTENTS 



Page 



I. General recommendations 6 



Drawbacks to be considered 8 



Relation to existing institutions 8 



Proposed observing station in the southern hemisphere 9 



Proposed observing station for solar investigation 13 



Auxiliary station for solar observations 18 



Advantages of a great reflector 18 



Policy of proposed Solar Observatory 19 



Problem of organization 20 



II. Proposed observatory in the southern hemisphere 21 



Problem of the sidereal system 21 



Need of more astronomical observers in the southern hemisphere 24 



Why observations are needed in the southern sky 26 



Works of observation proposed, and instrumental requirements 28 



( 1 ) Fundamental meridian observations 28 



(2 ) Complete observation of stars to the ninth magnitude 31 



(3) Measurement of stellar parallax 34 



(4) Measurement of radial motions 37 



(5) Observations of double stars. A large refractor 39 



Possible combination of (3) and (5 ) 40 



(6) Variation of latitude 41 



(7) Astrophysical researches 42 



(8) Astrographic chart 42 



(9) Photometric observations 43 



( 10) Researches of minor scope 43 



The question of site 43 



Buildings 46 



Staff and organization 47 



The Southern Observatory as an expedition 48 



III. Observatory for solar research 49 



Purpose of a solar observatory 50 



Advantages to be gained through improved atmospheric conditions. ... 52 

 New types of reflecting telescopes and their use in conjunction with 



laboratory instruments 54 



General nature of the principal problems of solar research 59 



Constitution of the sun 59 



Heat radiation of the sun 62 



Evolution of the sun and stars 64 



(5) 



