188 ANNUAL OF SCIENTIFIC DISCOVERY. 



moment of the existence of such a nebulous mass would be inaugurated by 

 the election of a centre of gravity, and, instantly after, every particle through- 

 out the entire mass of such nebulas would tend to and converge towards that 

 centre of gravity. Let us now consider what would be the result of this. 

 It appears to me that the inevitable consequence of the convergence of the 

 particles towards the centre of gravity of such a nebulous mass would not 

 only result in the formation of a nucleus, but by reason of the physical impos- 

 sibility that all the converging particles should arrive at the focus of conver- 

 gence in directions perfectly radial and diametrically opposite to each other, 

 however slight the degree of deviation from the absolute diametrically opposite 

 direction in which the converging particles coalesce at the focus of attraction, 

 a twisting action would result, and rotation ensue, which, once engendered, 

 be its intensity ever so slight, from that instant forward the nucleus would con- 

 tinue to revolve, and all the particles which its attraction would cause to 

 coalesce with it, would do so in directions tangential to its surface, and not 

 diametrically towards its centre. In due course of time the entire of the 

 remaining nebulous mass would become affected with rotation from the more 

 rapidly moving centre, and would assume what appears to me to be their 

 inherent normal condition, namely, spirality, as the prevailing character of 

 their structure : and as that is actually the aspect which may be said to 

 characterize the majority of those marvellous nebula?, as revealed to us by 

 Lord Rosse's magnificent telescope, I am strongly impressed with the con- 

 viction that such reasons as I have assigned have been the cause of their 

 spiral aspect and arrangement. And by following up the same train of rea- 

 soning, it appears to me that we may catch a glimpse of the primeval cause 

 of the rotation of every body throughout the regions of space, whether they 

 be nebulae, stars, double stars, or planetary systems. The primary cause of 

 rotation which I have endeavored to describe in the preceding remarks is 

 essentially cosmical, and is the direct and immediate offspring of the action 

 of gravitation on matter in a diffused, nebulous, and, as such, highly mobile 

 condition. It will be obvious that in the case of a nebulous mass, whose 

 matter is unequally distributed, that in such a case several sub-centres of 

 gravity would be elected, that is to say. each patch of nebulous matter would 

 have its own centre of gravity ; but these in their turn subordinate to that 

 of the common centre of gravity of the whole system, about which all such 

 outlying parts would revolve. Each of the portions above alluded to would 

 either be attracted by the superior mass, and pass in towards it as a wisp of 

 nebulous matter, or else establish perfect individual and distinct rotation with- 

 in itself, and finally revolve about the great common centre of gravity of the 

 whole. Bearing this in mind, and referring to some of the figures of the 

 marvellous spiral nebula? which Lord Rosse's telescope has revealed to us, I 

 shall now bring these suggestions to a conclusion. I have avoided expand- 

 ing them to the extent I feel the subject to be worthy and capable of; but I 

 trust such as I have offered will be sufficient to convey a pretty clear idea 

 of my views on this sublime subject, which I trust may receive the careful 

 consideration its nature entitles it to. Let any one carefully reflect on the 

 reason why water assumes a rotary motion when a portion of it is permitted 



