1912] The Ottawa Naturalist. 29 



THE EVOLUTION OF THE WORLDS.* 



By J. S. Plaskett, B.A.. F.R.S.C, Tin-: Observatory, Ottawa. 



I have felt considerable difficulty in preparing a suitable 

 paper for presentation to the Ottawa Field-Naturalists' Club. 

 The connection between natural history and astronomy is so 

 slight that no subject was known to me, forming a sufficient 

 connecting link between the I Lences, to base a paper upon. 



It was only upon learning that it was not essential for the paper 

 to have any direct relation with the natural sciences that I 

 undertook to prepare it. Although it is almost entirely astro- 

 nomical in character yet the title suggests some analogy to one 

 of the most important developments in your science, that of 

 evolution. I hope to be able to trace for you. if only in an 

 imperfect way, how the development of the celestial universe 

 has taken place, and I think we will find as we go along, that 

 there is in some respects considerable similarity in the scheme 

 of evolution in the two sciences. 



Although we, in our feeble way, can trace the process of 

 development from the original primal material in its simplest 

 forms to the very complex manifestations that we see all around 

 us, both on the earth and in the heavens, and can see that this 

 development in both sciences has followed by the operations, 

 of laws, which, simple in themselves, are yet so perfect and 

 complete and far reaching as to excite our admiration and awe, 

 vet we have in the very beginning to start with the Creator. 

 Surely there is not one of us but feels that such a plan of creation 

 as is here implied requires a higher, wider, and nobler concep- 

 tion of the Almighty Ruler of the Universe than the one which 

 imagines it to have been made, as it were, in a moment. 



It is only within comparatively recent years that we have 

 been able to enunciate any definite theories in regard to the 

 constitution and mode of formation of the universe and its 

 component parts, in which is included, as a very insignificant 

 portion, our own solar system. Undoubtedly the one discovery 

 leading to this advance was that of the principles of spectrum 

 analysis, first definitely enunciated by Kirchoff in 1859. On 

 this epoch-making discovery is based the whole science of 

 astrophysics, sometimes called the new r astronomy, which treats 

 of the constitution of the heavenly bodies, as apart from their 

 positions and motions in the celestial sphere, which is the pro- 

 vince of the older astronomy, or astrometry as it is now some- 

 times called. 



*A Lecture given before the Ottawa Field-Xaturalists' Club, 27th 

 February, 1912. 



