552 Transactions. — Miscellaneous. 



57. If two nebulae come into a slight grazing impact there 

 will result a double nebula, which will show a spindle at the 

 centre. As they are parting company they may have tem- 

 porarily a dumb-bell appearance ; but, as the two sides of the 

 coalesced nebula are moving in opposite directions, a spiral 

 begins to form at the centre. As the ends travel on in space 

 the spiral would increase, and ultimately a double spiral 

 would result. 



58. One or both of the original nebulae may be entangled 

 in the spiral. 



59. If the impact be considerable, the two nebulae do not 

 escape each other, and an annular nebula results. It would 

 have gauze-like masses of nebulae at the poles of the ring, 

 produced by the outrush of gas during the impact. 



60. There are nebulae corresponding to every one of these 

 conditions : nebulae coming into impact — some in impact 

 with the spindle showing between them ; there are also 

 spindle nebulae left alone ; others with an incipient spiral 

 visible at the centre ; others where the spiral is more distinctly 

 visible ; and others where the double spiral is fully developed. 



61. Finally there are annular nebulae with the gauze-like 

 caps referred to above. Thus at one and the same time the 

 evolution of nebulae at any of its stages may be watched, and 

 not unlikely older drawings may show the less advanced stages 

 of the same nebulae. 



The Origin of the Galactic Universe. 



62. If two universes such as the Magellanic Clouds come 

 into grazing impact, an annular universe will result, the 

 poles of which will be covered with nebulous matter owing to 

 the outrush of gas during the millions of years of the impact. 



63. This principle of outrush needs some explanation. As 

 two globular masses close in upon each other, the motion will 

 lie chiefly in a plane which might be called the orbital plane. 

 It is obvious that the pressure of the heated gas resulting 

 from the impact, as the bodies close the gas in, can find no 

 escape in this orbital plane, but can only escape upwards and 

 downwards. 



61. Stars will pass into such caps of nebula as originally 

 covered the galactic poles, and will there be entrapped, and 

 will attract nebulous matter. They will thus become nebulous 

 stars ; or they may be volatilized altogether and become 

 globular nebulae. Such a distribution of nebulae exactly cor- 

 responds with our universe. 



65. Where globular nebulae are thick we should expect 

 double, spindle, and spiral nebulae. These nebulae are actually 

 found amongst the nebulae at the polar caps of the Milky Way. 

 Again, where stars are thick we should expect planetary 



