BrckERTON.— On the Genesis of Worlds and Systems, 195 
collision a second time, and, even as an extreme possibility, more than 
twice; and it does not appear unlikely that this is really the case with 
Tycho Brahe’s temporary star. There is one thing that makes it likely. 
All the text-books speak of it as a possible variable with a period of 313 
years, Now, it appeared absolutely certain that if such a thing as consecu- 
tive collision did happen, it would be longer between the first pair of impacts 
than between the second pair of impacts; and, on taking the dates given by 
Herschel, it was found that the first interval was 319 and the second 308 
years, thus adding another to the very remarkable series of coincidences 
which have been found in working out this hypothesis. 
But people are never satisfied without trying to ride a hobby to death ; 
and really it does seem going rather to extremes to suggest, as has been 
done, that nearly all we see in the heavens—all the millions of suns, all the 
nebule—are parts of one great system produced by the impact of two 
stupendous bodies meeting in free space—a system so extensive, that it 
would probably take light at least a hundred years to pass through the 
mass ; while of the bodies themselves, some are so big that the number of 
times our sun would be required to measure their volume must be reckoned 
by thousands. Thus has the hobby been goaded on, and it is not absolutely 
certain that it has thrown its riders yet. It is true Proctor has been for 
years carefully laying down a veritable railroad for just such a hobby ; when 
. he was working out his great research on the visible universe, so that it was 
easy work for it, it ran like a snowball down a hill, gathering speed and 
proportion as it went. But I must tell you how Proctor did this work. He 
collected statistics of the number of stars and nebule, of star-clusters and 
star-motion. He and his friends placed all these on charts, and when they 
were finished, a single undoubted system was seen, which he describes 
roughly as a ring or spiral of stars, with our solar system at or about the 
centre, and with two caps of nebule covering the poles of this ring. So 
when the picture of the visible universe, given by Proctor, came to be 
examined, it was found to be so like that which had been suggested as 
likely to result from “ partial impact," that it was felt the visible universe 
itself must be one of its numerous offspring. 
But what does such an idea of the origin of the universe suggest to our 
mind of the contents of space generally? Clearly, that if two such bodies, 
why not many, some almost infinitely large compared to them? Why not 
go with Kant, and think that as the earth and its moon are part of the Solar 
System, as this system is part of the galaxy, why not the galaxy a part of a 
still more imposing system ? Anyhow, the idea of space, suggested by this 
theory, is that it contains an infinite number of masses, varying in size 
from the particle of hydrogen to the stupendous mass which physicists look 
forward to as the final condition of the visible universe. 
