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of them can be said to have any distinct and ascertainable 
parallax ; the rest being too remote for positive calculation by 
any such means. Of these nine, a Centauri is the nearest, 
being about 22 billions of miles distant ; Sirius, a little under 
90 billions of miles; and Arcturus, 160 billions, the light from 
which latter must therefore require tweuty-six years to reach 
the earth. To Bessel, Henderson, and Peters belong the honour 
of these most important discoveries. 
14. Such results, however, are as nothing when compared 
with the still more splendid discoveries of the two Herschels 
in relation to the Milky Way — that magnificent galaxy of stars 
which spreads across the heavens like a broad zone of light, and 
is familiar to the commonest observers. Submitting this mighty 
range of stars to his great reflecting telescope, which had an 
aperture of 18 inches with a focal length of 20 feet, and a 
magnifying power of 180, Sir W. Ilerscliel found that the 
distances of many of these stars from the earth must be 750 
times greater than the distance of an average star of the first 
magnitude such as a Centauri. As, therefore, this latter star 
requires years to send us its light, it follows that the light 
from the Milky Way requires more than 2,656 years to reach 
us. Through the researches of the same great astronomer we 
learn also that the number of stars in this stupendous creation 
is from twenty to thirty millions; and that its entire length 
extends to about 60,000 billions of miles. This being so, the 
time which light takes to pass from one extremity to the other 
must be nearly 1 0,000 years. 
15. But we have not done yet. For under the scrutiny of our 
most powerful telescopes a variety of nebulae have been dis- 
covered, about 5,000 in number, — being systems of other stars 
still more remote than those in the Milky Way, — some of them 
being from 7,000 to 8,000 times the distance of our nearest 
fixed stars. Consequently, about 30,000 years must at least 
have elapsed since their creation, otherwise a sight of them 
would never have reached the eyes of our telescopic observers. 
Nor, is this all. For, to use the words of Professor Birks, “ If 
the distance of these nebulous systems from each other, com- 
pared with their own magnitude, bears any resemblance to the 
distance which separates each planetary system from the nearest 
fixed stars, it is not unlikely that the intervals of many of the 
nebulaj are 1,000 times greater than the utmost extent of the 
Milky Way, or not less than 60 trillions of miles. Such 
a remoteness is really inconceivable,” he adds, “ since 
light itself, in traversing it, would occupy almost 10 millions 
of years. 5 ’ 
16. From all this, then, it becomes very obvious that, by a 
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