ISO PLEASANT WAYS IN SCIENCE. 



of the sidereal system, is its amazing vitality. Instead of 

 millions of inert masses, we see the whole heavens instinct 

 with energy astir with busy life. The great masses of 

 luminous vapour, though occupying countless millions of 

 cubic miles of space, are moved by unknown forces like 

 clouds before the summer breeze ; star-mist is condensing 

 into clusters ; star-clusters are forming into suns ; streams 

 and clusters of minor orbs are swayed by unknown attractive 

 energies ; and primary suns singly or in systems are pursu- 

 ing their stately path through space, rejoicing as giants to run 

 their course, extending on all sides the mighty arm of their 

 attraction, gathering from ever-new regions of space supplies 

 of motive energy, to be transformed into the various forms 

 of force light and heat and electricity and distributed 

 in lavish abundance to the worlds which circle round them. 

 Truly may I say, in conclusion, that whether we regard 

 its vast extent, its infinite variety, or the amazing vitality 

 which pervades its every portion, the sidereal system is, of 

 all the subjects man can study, the most imposing and the 

 most stupendous. It is as a book full of mighty problems 

 of problems which are as yet almost untouched by man, 

 of problems which it might seem hopeless for him to attempt 

 to solve. But those problems are given to him for solution, 

 and he -will solve them, whenever he dares attempt to de- 

 cipher aright the records of that wondrous volume. 



