DEPARTMENT OF MERIDIAN ASTROMETRY.* 



Benjamin Boss, Director. 



A glance at the reports of the Department of Meridian Astrometry 

 would seem to indicate that special investigations form the bulk of the 

 activities of the Department, because of the amount of space devoted 

 to these investigations in the reports as compared with that devoted to 

 outlining the observational and computational work upon the general 

 catalogue. This, however, is not the case. Such a great under- 

 taking as we have in hand can only proceed by stages, for reasons of 

 economy. These operations, though absolutely essential to the final 

 results, present few elements of special interest to the general scientific 

 public and therefore are barely referred to in the reports, though each 

 operation may occupy the time of a number of computers for months. 

 In this respect our work differs largely from that of many other scien- 

 tific organizations wherein the investigations call for a comparatively 

 short efifort, so that many investigations are completed within a brief 

 time. 



The manner in which our reduction of observations is conducted is 

 also responsible for our inability to supply, in advance, data required by 

 other observatories. To make special reductions to supplj'' data for 

 a few individual star places would double the cost of reduction for 

 these stars and the advance star places would be less accurate than the 

 finally deduced places. 



The San Luis observations will very shortly be in such shape that 

 they can be prepared for the printer. It is a matter deserving of 

 careful consideration whether these results should be published as a 

 separate catalogue. In one sense of the word the southern observations 

 form a completed task, but they will eventually be combined with the 

 northern observations to form a continuous catalogue from pole to pole. 

 In the process of combination the observed positions will be altered by 

 such amounts as are found necessary to bring southern and northern 

 star positions into agreement, and for a zone extending from the zenith 

 at Albany to the zenith at San Luis the positions of fundamental stars 

 will be formed by a combination of northern and southern observations. 

 For such stars it would be possible to print the positions of the separate 

 catalogues in special columns. On the other hand, by printing the 

 catalogues separately the San Luis observations would become avail- 

 able in advance of the northern observations, and by the subsequent 

 publication of tables of correction, the position of each catalogue could 

 be readily deduced with a small amount of labor. 



The collection of the observations upon the catalogue cards is begun. 



♦Address: Dudley Observatory, Albanj% N. Y. 



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