226 Royal Astronomical Society. 



individuals of which the new groups must be composed, it will be 

 easy at any future time to pass, by a single table of synonyms and 

 by one decided step, from one to the other system, whenever the 

 convenience and consent of astronomers may dictate the propriety of 

 a change. Such views, if entertained, would render the nomencla- 

 ture of the present catalogues so far provisional that a more rational 

 and convenient system of groups (confined not to the southern hemi- 

 sphere, but extending over both) may yet be contemplated by astro- 

 nomers. Nevertheless, so long as the ancient system is at all re- 

 tained, a general and scrupulous adherence to the nomenclature here 

 adopted is most earnestly recommended to the astronomical world, 

 as the only mode of escape from that state of confusion at present 

 quite intolerable. As regards the southern constellations, the fol- 

 lowing are the principles proposed ; viz. 



1. That all the constellations adopted by Lacaille be retained, and 

 his arrangement of the stars preserved ; subject, however, to certain 

 alterations hereafter specified. 



2. That all the stars, having a doubtful location, such as those 

 which Lacaille (after the manner of Ptolemy) has considered as ajw-o'/j- 

 <pu}Toi (unformed), be included within the boundaries of either one or 

 other of the contiguous constellations, so as to preserve a regularity 

 of outline and nomenclature. 



3. That all the rest of Lacaille's stars be placed within the boun- 

 daries laid down by him, with the following exceptions : — First, a 

 few stars which are located too far from the border of the constella- 

 tions in which they are registered, to admit of an uniform contour of 

 the lines. Secondly, such stars as have been previously observed 

 by Ptolemy or Flamsteed, and by them located in other constella- 

 tions, or which interlace and are confusedly mixed with such previ- 

 ously observed stars*. Thirdly, the four stars that are placed by 

 Lacaille in the end of the Spear of Indus, but which are now assumed 

 to form part of the constellation Pavo, in order to render the con- 

 tour of these two constellations less circuitous. 



4. That the letters, selected by Lacaille, be adopted in preference 

 to those introduced by Bayer in Argo, Centaurus, Ara and Lupus. 

 That the Greek letters (with a few exceptions) be retained only as 

 far as stars of the fifth magnitude inclusive. That no Roman letters 

 be at present used, except in the subdivisions of Argo, subsequently 

 mentioned. 



5. That Argo be divided into four separate constellations, as partly 

 contemplated by Lacaille ; retaining his designations of Carina, 



* A single exception to this rule occurs in the case of the last star in the 

 constellation Piscis Australis, in Ptolemy's catalogue, which Bayer has de- 

 noted by the letter x., and which is presumed to be the same as that which 

 has been designated by Lacaille as y Gruis. As there is some ambiguity, 

 however, in the position of this star in Bayer's map, it is assumed (like some 

 other stars already mentioned) as common to both constellations, in order 

 to adjust this discordance; nnd, in the catalogue above-mentioned, La- 

 caille's designation of y Gruis is retained, on account of its forming the 

 principal object in the head of that constellation. 



