REPORT OF COMMITTEE ON OBSERVATORIES 4I 



hours which, on the whole, would be most suitable for the observer 

 of double stars. 



This arrangement is not suggested as ideal, but as one which 

 might be adopted should the program for (5) be carried out and that 

 for (3) be somewhat restricted. In that event we think the ar- 

 rangement here suggested would be very much preferable, as it cer- 

 tainly would be very much more economical. 



(6) Variation of Latitude. 



The variation of the earth's axis of rotation is one of the newest 

 and most interesting developments of astronomy. The facts relating 

 to it have an intimate bearing upon the question of precision in 

 meridian observations, in addition to the great interest which at- 

 taches to it as a physical phenomenon. Astronomy has not yet 

 formed an adequate explanation of its origin. Quite recently Mr. 

 Kimura, of the Japanese international latitude station, has called 

 attention to a singular phenomenon developed by the international 

 observations, which may be referred to several possible explanations, 

 none of which appear quite satisfactory. In consequence of this, 

 Dr. Chandler, editor of the Astronomical Journal, points out the 

 necessity for establishing three observing stations in the southern 

 hemisphere — one at the Cape of Good Hope, another at Sydney, and 

 still another about 30 miles south of Santiago de Chile. This propo- 

 .sition has been heartily indorsed by several high authorities, in- 

 cluding the Royal Astronomical Society. The operation of these 

 three stations would tend to fix and define this anomaly in the ob- 

 servations beyond a doubt, and the result might be that the true 

 cause of the phenomenon in question would be pointed out. Fur- 

 thermore, the execution of this project would bring a most valuable 

 contribution to the question of astronomical aberration. 



We are strongly impressed with the importance of this work 

 and are of opinion that, if the stations at the Cape of Good Hope 

 and Sydney could be provided for by other agencies, the Carnegie 

 Institution would do well to take the responsibility of the station in 

 Chile. The annual expenditure would not be very great, and this 

 project need not stand or fall with that for the Southern Observa- 

 tory, although it has a logical connection with it. 



The zenith telescope and observing shed required would not be 

 costly, and two observers, without other as.sistants, would be able 

 to take care of the obsen'-ations and computations. 

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