THE EARTH AT ITS BEGINNING 



which we are uncertain. In other parts of the sky there 

 are great masses of this starry mist ; and to these bright 

 patches astronomers have given the name of "nebulae." 

 The most wonderful of them all is the great nebula in 

 Orion ; x and one of the most beautiful is the great spiral 

 nebula of Andromeda. These objects are not only won- 

 derful and beautiful ; they also give us a hint as to what 

 might have been the earliest state of our earth, and of 

 the Sun itself in those almost inconceivably distant ages 

 before order took the place of chaos. 



Let us ask the reader to imagine what would take place 

 if the earth were to come into collision with another 

 planet. Some of our readers, at any rate, will know that 

 the Sun and all its planets the earth among them is 

 moving swiftly to some unknown destination among the 

 stars. 2 Suppose that some great planet, not of the Solar 

 System, barred our path. We should not be taken wholly 

 unawares, for astronomers would know of the approach of 

 the star and our earth to one another months, and perhaps 

 years, beforehand. That would be because the light of 

 the Sun falling on it would be reflected, just as the reflec- 

 tion of the Sun's rays light up the Moon for our eyes. If 

 the strange planet were a very large body, like the sun 

 for bigness, it would become visible far beyond the con- 

 fines of the Solar System. It might first be taken for 

 a new star such as sometimes blazes up in the sky and 



1 " God maketh Arcturus, Orion, and Pleiades, and the chambers 

 of the south " (Job ix. 9). 



2 It is usually supposed that this movement, amounting to perhaps 

 ten miles a second, is in the direction of the constellation of Vega. 



92 



