REPORT OF COMMITTEE ON OBSERVATORIES 33 



the Astrographic Chart. It will be found, however, that the so-called 

 zone observation of telescopic stars may easily be brought to a very 

 much higher grade of accuracy than that which has prevailed hith- 

 erto, without any material sacrifice of the rapidity with which they 

 can be made. This can be effected in three ways : 



(«) By the use of a superior instrument. 

 (d) B}^ the use of a more accurate and more extensive stand- 

 ard catalogue, rendered possible under ( i ) . 

 (c) Through a better organization in methods of observation. 



Then with the addition of about one fourth the number of obser- 

 vations which would be needed under (2), without reference to any 

 ulterior use, we shall be able to complete the Astrononiische Gescll- 

 schaft zones and at the same time meet the requirements of the 

 Astrographic Chart ; and we strongly recommend that this pro- 

 gram be adopted. 



The necessity of this extended program is all the more pressing 

 because of the extremely doubtful probability that the observations 

 for the basis of the Astrographic Chart can be secured by means of 

 existing agencies with the requisite completeness and accuracy. 



The argument that the positions of all the stars down to the ninth 

 magnitude (and fainter) in the southern hemisphere can hereafter 

 be derived from the Astrographic Chart assumes that we may look 

 for the completion of that undertaking within a few years. The 

 probability that the completion of certain important sections of that 

 work may be delayed for a longer time than would be desirable, 

 however, seems to be warranted by an examination of the situation. 

 On the other hand, it seems very desirable that the great undertak- 

 ing entered upon thirty five years ago for the determination by 

 meridian observation of the position of all stars down to the ninth 

 magnitude in the whole heavens should be completed. 



The proposed Southern Observatory has here an opportunity to 

 carry out a work which would have enough of intrinsic interest in 

 and for itself, but which would possess the great added advantage 

 of serving as the fundamental basis of another work even greater in 

 extent than itself. It would also much increase the value of similar 

 work already accomplished in the northern hemisphere. Further- 

 more, it would scarcely be possible to carry out the work proposed 

 next in order (3) in an economical, effective, and comprehensive 

 way, as to stars in sensible motion, without the completion of (2). 



For this work there should be a corps of five or six observers and 



