70 Stellar and Planetary Evolution. 



strange bodies. Professor Bond, of Cambridge, America, has, 

 however, ventured to ascribe to the great nebula in the 

 constellation Andromeda a distance eqvivalent to about sixty- 

 five years of light travel — ?>., light travelling from that far-away 

 object would then require a period of sixty-five years to reach 

 our earth, at the enormous velocity at which we know that light 

 does travel through the ether of space, 186,000 miles in each 

 second, or eleven millions of miles in one minute. 



The lecturer next proceeded to discuss the celebrated nebular 

 hypothesis of the French astronomer Laplace, which was des- 

 cribed as being a modification of the theory of the great Sir 

 William Herschel, and which postulated that by the known 

 laws of gravitation, and from such a partially condensed mass 

 of primordial matter as one of those mysterious nebulae, an 

 entire planetary system such as our own, with its train of 

 subordinate satellites, could be, and most probably had been 

 produced. This great speculation of Laplace was based mainly 

 upon the famous nebular hypothesis formulated[by the German 

 philosopher Immanuel Kant, which provided that aeons of ages 

 ago the cosmical matter which now constitutes our stars, planets, 

 and other heavenly bodies was in a much different condition to 

 that in which we now "find it. It was diffused everywhere 

 throughout space, instead'of being gathered together and com- 

 pacted into individual bodies as at present. Centres became 

 established, towards which the cosmical matter became attracted 

 and separate masses of the most stupendous character were thus 

 formed. The process was repeated in each of these masses, 

 which were thus broken up into smaller masses, and again in 

 the smaller masses the process^was still further repeated, and 

 thus did the German philosopher Kant account for the evolution 

 of suns and their planets and satellites. The great nebula of the 

 Pleiades was given as an example of the isolation and compaction 

 of the nebulous matter into stellar bodies. Laplace's theory 

 postulated that millions of ages ago the nucleus of an enormous 

 mass of vapour (in fact, a stupendous nebula) embraced the entire 



