Solar and Planetary Evolution. 71 



ABSTRACT OF THE DISCUSSION. 



Dr. Robert G. Eccles: — 



The lecture of Mr. Serviss lias been highly interesting as well 

 as instructive. He has handled his subject with a degree of ability 

 and candor highly praiseworthy. 



The nebular theory of Laplace is a very fascinating one, and at 

 first sight seems to give us a picture of conditions that might 

 have evolved our Solar System. Its fundamental principles are 

 undoubtedly sound, but the more we study the matter in detail 

 the less likely we are to acquiesce in it as a conclusion. The 

 speaker has already called our attention to a number of weak 

 points, and told us of several modifications of it which have been 

 adopted by leading astronomers. The fact that irresolvable neb- 

 ulae exist, and that the spectroscope declares them to be in a 

 gaseous condition, is beyond dispute. The further fact that 

 science, in retracing the earth's history, is irresistably carried 

 back to a condition of intense heat as the primal cosmic state, is 

 equally true. So far all are agreed. To look upon the pictures of 

 the various nebulae which have been shown us to-night seems, to 

 my way of thinking, to pretty thoroughly negative the conclusions 

 of Laplace. At least they do not seem destined to form any such 

 systems as ours is. The lack of serial connection, as well as lack 

 of uniformity in their conformation, seems to show that no two of 

 them are rushing toward a common destiny. Some do show a 

 suggestion of a whirl, but not of the Laplacean type. 



Such a theory seems to me to violate the basic laws believed in 

 by modern evolutionists. It begins with a highly specialized form 

 of motion, and gives no hint as to its genesis. There is altogether 

 too much order, where we should find chaos. What is the cause 

 of the rotation ? Why does the matter all tend to one rather than 

 many common centers ? We have numerous reasons for believing 

 that a mass so vast, when cooling, would not cool evenly, nor 

 move evenly. We have none for believing the contrary. The neb- 

 ula in Orion looks very like an ideal of the primitive state of 

 this solar system which I presented at a meeting of the old Brook- 

 lyn Philosophical Society many years ago, and at which our present 



