REPORT OF COMMITTEE ON OBSERVATORIES 1 9 



tage in associating the two branches of study, solar and stellar, in 

 one establishment. But, aside from this, we think that the site 

 which has been provisionally selected (or a still better one if it can 

 be found) would be most admirably suited as the location for the 

 most powerful telescope that can be constructed. The occupancy of 

 this site for such a purpose seems to offer a rare opportunity that 

 ought not to be neglected. 



Furthermore, it is now conceded that the construction and suc- 

 cessful operation of a reflecting telescope, having a mirror five feet 

 in diameter, is entirely feasible. We have the benefit of experience, 

 both at the L,ick and Yerkes observatories, in demonstrating the 

 great advantages to certain researches in astronomy which may be 

 derived from the use of large reflectors. We feel no hesitation in 

 offering the prediction that researches in astrophysics would be en- 

 riched to a remarkable degree by the use of the largest reflectors that 

 can be made, and we would strongly urge the advisability of pro- 

 viding a very large reflecting telescope as part of the equipment of 

 the proposed observatories. 



Policy of proposed Solar Observatory. — Plans and estimates for a 

 Solar Observatory, and likewise for a Southern Observatory, have 

 been prepared upon our understanding that the Carnegie Institution 

 is not in favor of establishing permanent observatories, but that 

 works undertaken must be in the nature of expeditions for the solu- 

 tion of definite problems, in limited periods of time. In some ways 

 this policy seems to us to have advantages, especially in relation to 

 problems for whose solutions the instruments are of standard form 

 and for which the methods have been perfected and thoroughly 

 tested. Examples of this are meridian circle, heliometer, and mi- 

 crometric work generally. On the other hand, this policy is not a 

 natural one for those new works which call for developments in 

 instruments and methods. Some portions of the solar work and the 

 application of photography to parallax problems are examples of this. 



The task proposed for the Solar Observatory is only in part of a 

 routine character. A large part of its work ought to be one of de- 

 velopment, in relation to which it would be difficult to foresee, in all 

 its details, the exact character of the equipment which might be best 

 calculated to meet successive requirements of investigation as they 

 may arise. Consequently, we are of opinion that the director of the 

 proposed observatory should not be hampered with a rigid program 

 of method and equipment, prescribed in advance. 



