TIME AND SPACE DOUGLAS 155 



Having siirvej^ed the future, let us, in the light of this same 

 theory, glance backward in an endeavor to trace the origin of a 

 stellar cluster. Silberstein considers the possibility of a gaseous 

 mass or nebula giving rise to millions of individual concentrations 

 of matter, and thus forming the individual stars of a cluster. This 

 was essentially the primary postulate of Laplace, though he was 

 considering the relatively minute case of a nebula giving rise to a 

 solar system — an impossible hypothesis in the light of modern 

 knowledge. But as an explanation of the evolution of a small 

 galaxy of stars, like many of the star clusters revealed by the tele- 

 scope, it is by no means to be discarded — it may well be the true 

 solution of the problem, as was pointed out by Jeans some years ago. 

 When, however, an attempt is made to explain the origin of our 

 galaxy in this manner, it is found to be incapable of satisfying all 

 the conditions. Our galax}^, to quote yet another analogy taken by 

 Doctor Silberstein from the history of mankind, must have devel- 

 oped, like the far-flung British Empire, by the aggregation into one 

 conglomerate whole of many remnants of previous systems, systems 

 long since scattered to the four winds. 



Guided by some of the great thinkers of to-day, our thoughts have 

 traversed a^ons of time, contemplating some of the changes taking 

 place with majestic deliberation throughout the vastnesses of space. 

 "Time rolls 'his ceaseless course." A million million years suffice 

 for the birth of a star and its early development; a few hundred 

 thousand years will tell the tale of the life of mankind upon this 

 planet; and as for man, an individual man, the years of his life 

 are three score years and ten, and yet such is the power of a great 

 mind that, despite the brevity of its allotted span, it can wrestle with 

 the problems of nature and learn something at least of the immensi- 

 ties of space and time. 



BIBLIOGRAPHY 



A. S. Eddington : Masses and Liiminosities of the Stars. M. N. R. A. S. 

 March, 1924. 



J. H. Jeans : Monthly Notices Royal Astronomical Society. December, 1924. 



J. H. .Jeans : Cosmogony and Stellar Dynamics. 1919. 



H. Jeffreys : The Earth : Its origin, history, and physical constitution. 1924. 



L. Silberstein : Theory of Relativity. 1924. Chap. -VI and Miscellaneous 

 Notes. 



A. V. D. : Measuring the Universe. Discovery, September, 1924. 



