330 The Construction of the Heavens. [July, 
ciation of these streams of nebulz and stars could scarcely 
be regarded as accidental; but the fact that both sets of 
streams converge upon those very regions where stars and 
nebulz are so strangely intermingled removes all doubt 
from the conclusion that in the nebule (for these streams 
include all the known southern nebule) we have not to deal 
with external galaxies, but with objects belonging to the 
sidereal system. 
The charting of the stellar proper motions has further led 
me to the discovery of the fact that the stars in many parts 
of the heavens are travelling in systems—or as it were 
drifting—through space. Thus the five stars, 6, , 4, «, 
and ¢, Ursze Majoris, are found to be all moving together, as 
one grand scheme.* In Gemini there is a much more 
remarkable instance of drift, nearly all the stars of that 
constellation (Pollux is one of the exceptions) travelling in 
one general direction. In Taurus there is also well-marked 
drift. ‘These instances of drift suffice to afford independent 
testimony in favour of the existence of systems subordinate 
to the great sidereal system. 
The general conclusions to which I have been led by 
these and other methods of research, which space will not 
permit me to particularise further, are chiefly these :—The 
sidereal system is altogether more complicated, altogether 
more varied in structure, than has hitherto been supposed. 
Within one and the same region co-exist stars of many 
orders of real magnitude, the greatest being thousands of 
times larger than the least. All the nebule hitherto disco- 
vered, whether gaseous or stellar, irregular, planetary, ring- 
formed, or elliptic, exist within the limits of the sidereal 
system. They all form part and parcel of that wonderful 
system whose nearer and brighter parts constitute the 
glories of our nocturnal heavens. 
It has been supposed that the new views to which I have 
been led would, if accepted, tend to reduce our estimate of 
the scale on which the universe is constructed. ‘This, how- 
ever, is not the case. It is true that I cannot recognise in 
the clustering regions of the Milky Way the profundities 
commonly believed in; but I believe in profundities far 
vaster. It is true that I believe the varieties of structure 
* More than two years ago, speaking of this discovery, which I had then 
but recently made, I expressed my conviction that if ever Dr. Huggins was 
enabled to determine the proper motions of these stars in the line of sight, he 
would find them to be all travelling one way, either receding or approaching. 
Quite recently he has tested the matter, and he finds that not only have these 
five stars similar speétra unlike the spe@tra of a and n, but that whereas a is 
approaching, and 7 receding more slowly, the five are all receding at the rate 
of thirty miles per second. 
