150 Wisconsin Academy of Sciences^ Arts and Letters. 



are about to be, carefully observed at Greenwich; our Coast 

 Survey has requested a few specially neglected ones of these 

 degrees of brightness to be attended to at three or four 

 places. 



It may then be said that those astronomers who wish to 

 contribute to our knowledge of bright stars' places, have 

 only to supply such observations as they themselves use 

 for semi-fundamental purposes, and observe stars of the 

 seventh magnitude; and a few brighter which may have 

 been neglected. 



I have not yet mentioned the British Association Cata- 

 logue. This was published in 1853; its places and proper 

 motions were then inaccurate, and are now relatively much 

 worse, as great improvements have since been made in pre- 

 cision of observation. But the stars of this catalogue have 

 been greatly preferred in observatories, owing to its great 

 convenience as a working list; so that the general result 

 now is, that an astronomer who wishes to do anything not 

 superfluous, or liable soon to become so, must be very wary 

 in his work upon these stars. 



I have myself long kept an index of them, showing where 

 and when their positions have been lately determined; and 

 have thus saved myself much labor. The index is not quite 

 complete, even for the northern hemisphere; a considerable 

 portion of it is virtually published in my catalogue of 2,018 

 stars (Washington, War Department, 1879), and my manu- 

 scripts of the remainder are in such condition that I can 

 readily give authorities for any B. A. C. star north of the 

 equator. 



When the great zones are published (this is to be expected 

 to take place in portions for the next ten years), they will 

 contain comparisons with several old authorities, and will 

 thus indicate many new stars whose proper motions are to 

 be looked for. They will consequently be referred to for this 

 purpose by every one interested in this subject. 



Of least square discussions of this subject, published in 

 full, we have principally Madler's Bradley, vols. 14 and 16 of 

 the Dorpat observations, and volume 7 of the Bonn observa- 

 tions, which contains two long memoirs by Argelander. 



