384- Notices respecting New Books. 



from the principal star, and in polar distance from — 24' to +44', 

 comprising in the whole an area of almost exactly a square degree. 

 " It would be impossible by verbal description to give any just idea 

 of the capricious forms and irregular gradations of light affected by 

 the different branches and appendages of this nebula. Nor is it easy 

 for language to convey a full impression of the beauty and sublimity 

 of the sjoectacle it affords when viewed in a sweep, ushered in as it 

 is by so glorious and innumerable a procession of stars, to which it 

 forms a sort of climax, justifying expressions, which, though I find 

 them written in my Journal in the excitement of the moment, would 

 be thought extravagant if transferred to these pages. In fact, it is 

 impossible for anjr one, with the least spark of astronomical enthu- 

 siasm about him, to pass soberly in review, with a powerful telescope 

 and in a fine night, that portion of the southern sky. which is com- 

 prised between 6'' and 13^ of RA and from 146° to 149° NPD, 

 such are the variety and interest of the objects he will encounter, 

 and such the dazzling richness of the starry ground on which they 

 are represented to his gaze." — P. 38. 



The star ij Argus, which is suiTounded by this magnificent nebula, 

 is itself an object of no ordinary interest, on account of the singular 

 changes in lustre it appears to have undergone. In Halley's cata- 

 logue (1677) it is set down as a star of the 4th magnitude; in the 

 catalogues of Lacaille, Brisbane, Johnson, Fallows, and Taylor, as of 

 the 2nd. Sir John had himself been accustomed to regard it as of 

 the 2nd, or at most as a small star of the 1st. On the 16th of De- 

 cember 1837, he was astonished by seeing it appear as one of the 

 very brightest of the 1st magnitude. "It exceeded a Orionis, and 

 the only star (Sirius and Canopus excepted) which could at all be 

 compared with it was Rigel, which it somewhat surpassed." On the 

 28th of December it far surpassed Rigel, and equalled a Centauri ; 

 after the beginning of January it began to fall off. From subsequent 

 observations made by Mr. Maclear at the Cape, it appears that in 

 March 1843 it was superior to Canopus. About the 19th of that 

 month it began again to decrease. On the 3rd of January 1845 it 

 is described by Mr. Maclear as being again much larger than Cano- 

 pus. Sir John asks — " What origin can we ascribe to these sudden 

 flashes and relapses } What conclusions are we to draw as to the 

 comfort or habitabihty of a system depending for its light and heat on 

 so uncertain a source } " 



A general catalogue is given of the stars known to exist within 

 the limits of RA and PD which hound the monograph chart of 

 this singular object. They amount to no fewer than 1216. 



After this follows the " Reduced Observations of Nebulae and 

 Clusters of Stars." The catalogue occupies 78 pages, and gives 

 the following particulars: — 1st, the author's number; 2nd, the 

 synonym; 3rd, the RA for 1830; 4th, NPD for 1830; 5th, 

 description, remarks, &c. ; and 6th, the number of the sweep. By 

 means of the abbreviations we have already alluded to, the descrip- 

 tions are generally given in a very small space, frequently in a single 

 line. Many of the objects described are extremely remarkable. 



