64 PROGRESS OF SCIENCE IN THE CENTURY. 



turning around the sun and having a movement of 

 rotation around its own axis under the action of 

 gravitation. It was, indeed, a true revolution in 

 the theories that had been hitherto held, this theory 

 that fixed the sun in the firmament in spite of its 

 daily ascent and disappearance ; an idea that, at the 

 present day, has become familiar to us. And fur- 

 ther, we now know that neither is the sun itself 

 fixed, but that it is drawn with all its cortege of 

 planets along a course without end, across space with- 

 out limit Whence comes it and whither goes it? 

 Properly speaking, we know nothing about it, and 

 doubtless we will never know either its origin 

 or its end; but as the earth turns around this 

 movable sun, it hence results that our planet does 

 not describe a closed path, but a sort of spiral, and 

 that it never returns to a spot that it has once quitted. 

 Each second takes our planet to a new point in the 

 universe, and from this incessant displacement it 

 ought to follow that no phenomenon or event can 

 ever reproduce exactly any anterior phenomenon. 

 Clouds may resemble each other, as one sunrise re- 

 sembles another, but there is never an absolute coin- 

 cidence, and it would seem that these variations ought 

 to be perpetuated throughout the course of time that 

 is embraced by the history of humanity. 



" It would be useless to push further these con- 

 siderations, they are merely speculations; but they 

 lead to this thought, which, although unsupported, 

 continually recurs to our mind the possibility of a 

 progressive transformation of matter in a given direc- 

 tion, in that they show that everything that is with 

 us is drawn along in a dizzy course across an un- 

 known immensity." 



Let us return, however, to our particular point 



