Tlie Present State of our Knoivledge of Stellar Motion. 151 



Madler's Bradley is in the main superseded by Auwers' 

 but is often convenient to refer to as an index and approxi- 

 mate check for such stars as were defectively or poorly ob- 

 served by Bradley. 



Argelander's papers are indispensable to any one who 

 wishes to master the subject; they have been excelled in 

 small details, hardly in general plan. The miscellaneous 

 list of considerable proper motions which the great astrono- 

 mer here gives deserves occasional reobservation, as many of 

 the stars were poorly observed before him. 



There are four large catalogues lately published by four 

 departments of the United States government, viz.: Mr. 

 Boss's declinations of 500 stars, by the State Department; my 

 own catalogue of 2,018 stars, both right ascensions and de- 

 clinations, by the War Department; Prof. Newcomb's, of 

 1,098 stars, by the Navy Department; and the Coast Survey 

 list of 1,463, by the Treasury Department. The first is ad- 

 mirable in all respects; Prof. Boss took a great deal of pains 

 and spent much time; but the right ascensions are lacking. 

 My own work was for a practical end, which did not allow 

 either the means or the time for so complete a discussion of 

 four times as many stars; j but I think a great many trust- 

 worthy proper motions were detected by its means. I hope 

 by-and-by to observe the few stars in this catalogue which 

 are now at all uncertain, owing to lack of older observa- 

 tions. Prof. Newcomb's catalogue is, for the smaller non- 

 fundamental stars, much in the same condition as my own. 

 The coast survey computers have contented themselves with 

 the rather inaccurate proper motions of the B. A. catalogue, 

 and with a rather defective collection of modern authorities; 

 so that the present errors of their declinations are large. 

 They do not add right ascensions more accurate than to 

 whole seconds of time, which is, of course, entirely proper for 

 their purpose. In order to completely utilize for theoretical 

 purposes the three government catalogues first mentioned, 

 Mr. Boss's needs to be completed by adding right ascensions, 

 and the other two — in fact all three — by revisions where- 

 ever the material at hand was deficient. 



In the southern hemisphere, and especially in the southern- 



