266 Mary Somerviile. 



or even in the press. Far from it I do not expect to 

 " go to press " before another year has elapsed, for 

 though I have got my catalogues of Southern nebulae 

 and Double stars reduced and arranged, yet there is a 

 great deal of other matter still to be worked through, and 

 I have every description of reduction entirely to execute 

 myself. These are very tedious, and I am a very slow 

 computer, and have been continually taken off the sub- 

 ject by other matter, forced upon me by " pressure from 

 without." What I am now engaged on is the monograph 

 of the principal Southern Nebulas, the object of which is 

 to put on record every ascertainable particular of their 

 actual appearance and the stars visible in them, so as to 

 satisfy future observers whether new stars have appeared, 

 or changes taken place in the nebulosity. To what an 

 extent this work may go you may judge from the fact 

 that the catalogue of visible stars actually mapped down 

 in their places within the space of less than a square 

 degree in the nebula about r; Argus which I have just 

 completed comprises between 1300 and 1400 stars. 

 This is indeed a stupendous object. It is a vastly ex- 

 tensive branching and looped nebula, in the centre of the 

 densest part of which is T? Argus, itself a most remark- 

 able star, seeing that from the fourth magnitude which it 

 had in Ptolemy's time, it has risen (by sudden starts, and 

 not gradually) to such a degree of brilliancy as now 

 actuall} 7 to surpass Canopus, and to be second only to 

 Sinus. One of these leaps I myself witnessed when in 

 the interval of ceasing to observe it in one year, and re- 

 suming its observation in two or three months after in 

 the next, it had sprung over the heads of all the stars of 

 the first magnitude, from Fomalhaut and Regulus (the 

 two least of them) to a Centauri, which it then just 



