THE PHYSICAL PHENOMENA OF OTHER WORLDS. 315 
Another nebula is described as consisting of two loops like 
capital Greek Omegas — the one bright^ the other exceedingly 
faint — connected at their bases by a broad and very bright 
band of nebulae. The nebula in the sword-handle of Orion is 
thus described: — form the brightest portion offers a 
resemblance to the head and yawning jaws of some monstrous 
animal^ with a sort of proboscis running out from the snout 
Amongst other shapes assumed by these mysterious objects 
no less than fourteen have been detected by Lord Rosse to 
give unequivocal indications of a spiral structure~they have 
^‘’been founds in fact_, to be composed of a series of spiral 
convolutions^ arranged with remarkable regularity.^^ 
Let us briefly repeat the conditions observed in the vast 
material universe of stars which we have traversed. There 
are Insulated stars, such as Arcturus, Sirius_, and our own 
Sun^ each adapted for constituting the centres of planetary 
systems. There are Binary, Triple, and Multiple stars. Clus- 
tering collections, and the Milky Way. There are nebulous stars — 
the star in each case is situated exactly in the centre of the 
nebulosity^ showing that some physical relation connects them 
together. There are Planetary nehulce, always perfectly round 
in form^ and of a pale uniform aspect. There are Stellar 
nebulae and Milky nebulosities ; these were supposed by the 
elder Herschel to be clusters of stars^ which it was impossible 
to discern individually in consequence of the immense distance 
at which they are placed from any human observer. This 
profound astronomer calculated that the light from one of 
the faint nebulse seen in his forty-feet telescope^ must have 
occupied about 2_,000_,000 years in its passage to the earth, 
although traversing space at the rate of 192,000 miles in a 
second ! 
Is it possible, some one may ask, for man to determine, 
within any ordinary limits of probabihty, the physical consti- 
tution of those remote worlds ? To this, the most thinking 
men of the day unhesitatingly reply — It is possible ! Seeing 
that our Sun is 91,328,600 miles from us, and that we have 
determined, by methods described in the last number of the 
Popular Science Review, many of the physical phenomena 
which are active upon its surface, what is there to prevent 
our applying the same method to determine the condition of 
the Log star, which is 141,421 times more distant from the 
earth than the Sun is ? Then, if we And that the means which 
we are employing to tell us something of stellar matter 
answers to the trial of this vast distance, what is to hinder us 
from interrogating in the same way the stars which are ten 
times more distant than Sirius ; or the nebulge, which may be 
a hundred or a thousand times still more remote ? 
