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of plan and structure, which points evidently to the assumption 
of one guiding and controlling mind, and, even at the distance 
of Arcturus, we are familiar with the phenomena presented ; in 
fact we seem to be at home. 
With one still more extended survey of the realms of un- 
limited space, I will conclude this brief and imperfect review 
of the recent teachings of Astronomical science. 
Our speculations and our knowledge about the stars excite 
our imaginations, and inspire us sufficiently with awe and 
wonder, though the astronomer has little need for guesses, 
and is guided in his legitimate deductions by the severe rules 
of the inductive philosophy. 
But we have still to deal with another class of objects which 
give us a still nearer insight into the constitution of the 
universe, namely the nebulae and star-clusters. 
These, in the telescope, cloud-like looking objects were first 
observed and described in great numbers by Sir W. Her- 
schel, and to him science owes a very great debt of gratitude, 
for his wonderful labours in this department of astronomy. 
The two classes, nebulas and star-clusters, are with ordinary 
telescopes in general un distinguishable, but Sir William by 
using high powers on his gigantic reflector succeeded in re- 
solving in a great many instances the nebulous mass into its 
constituent elements of stars. Lord Rosse with his immense 
reflecting telescope resolved a great number of others which 
had not yielded to the inferior optical resources of Sir William. 
Then came an important question on which depended in a 
great measure the truth or falsehood of La Place’s theory of 
the constitution of the universe out of nebulous matter; namely, 
whether there were any nebula) actually irresolvable, or con- 
sisting of really nebulous matter, and not of aggregations 
of stars too far distant to be separately visible by any existing 
optical power. 
The spectroscope has satisfactorily answered the question, 
and, in the opinion of most persons competent to judge, 
decided that La Place’s theory was essentially correct, and 
we may assume that the existing solar system, and all other 
similar systems, were formed from matter in the nebulous state. 
The possibility of the truth of the theory on mechanical grounds 
was seen at once, and the fact of the existence of such matter 
(proved now beyond the possibility of doubt) scattered about 
in the heavens in various degrees of condensation, gives im- 
mensely greater assurance of the fact that this is the way 
in which it has pleased the Almighty to act in the creation 
and formation of the visible universe. 
