BiCKEKTON. — On the Origin of the Visible Universe. 175 



the spectrum of Mira Ceti, which I find thus described in my note-book, 

 under the date October 8th, 1878 : — " Saw to-night the spectrum of Mira : 

 it is really wonderful — something like that of a Herculis, as given by 

 Chambers. It seems to consist of bright broad bands, with narrow ones 

 in between. These bands are dark, but hardly black. The effect produced 

 is, as it were, that of an u'regular set of columns. The brighest part of the 

 spectrum is at the yellow and the green." 



a Piscis Australis (Fomalhaut). — This star is visible at home sometimes, 

 but its altitude there is so small that it can scarcely be properly observed 

 with the spectroscope. Fomalhaut is a first-class star of the most pro- 

 nounced type ; it is very remarkable for the great breadth of the F. hydro- 

 gen line. In Fomalhaut it is far broader than it is even in Sirius. As an 

 increase ua the breadth of the hydrogen lines has been shown to be due to 

 increased pressure, and as the increase in breadth is also proportional to 

 the pressm'e brought to bear upon the gas which gives the lines in the 

 spectrum, we may, I would venture to suggest, conclude that the pressure 

 at the surface of this star is extremely great. That is to say, Fomalhaut is 

 either extremely dense and compact, so that its radius is very small com- 

 pared with its mass (which is not very likely), or it is one of the very largest 

 stars in the sky. 



In conclusion, I would ask you to overlook any faults of style that may 

 be observable in this paper. It claims to be nothing more than its title 

 announces it to be — " Notes on Southern Stars." 



Aet. XIII. — Partial Impact (Paper No. 8) : On the Origin of the Visible 

 Universe. By Prof. A. W. Bickeeton, F.C.S., President of the Philo- 

 sophical Institute of Canterbury. 



[Read before the Philosophical Institute of Canterbury, ISth Feb., 1879.] 

 In the paper I am now submitting to the Institute, I shall attempt to show 

 that almost the whole of the visible universe may have been formed by two 

 stupendous bodies traveUing independently in free space, being brought 

 together by their mutual attraction, and coming into partial collision. I 

 shall in the first part explain the kind of system the naked eye and telescope 

 show the universe to be. Secondly, I shall attempt to show that a system 

 resembhng it most strikingly in its more salient features, corresponds to one 

 of the possible stages which would result from the partial collision of two 

 cosmical bodies. 



The belt of luminous cloud which is seen as a bow spanning the heavens 

 from horizon to horizon, is familiar to everyone ; and to a large number 



