ON LIGHT. 207 



almost infinite variety of particulars as to their intimate 

 nature and constitution (and,. as we shall see further on, 

 of their internal structure, and the mechanism by which 

 they are held together as bodies), which by no other 

 means we can obtain : information which at present we 

 are only imperfectly able to interpret, but whose import, 

 from year to year, and almost from week to week, is- 

 becoming better understood. Its language in this 

 respect bears no distant similitude to that of a series 

 of ancient inscriptions in some unknown tongue and 

 character. A single sentence once developed by some 

 happy and unmistakable concurrence of evidence, affords 

 a clue to others, which in their turn become the step- 

 ping-stones of further progress. By the one are revealed 

 the histories of ages long buried in oblivion, and of the 

 phases of human thought and action under circumstances 

 bearing little analogy to anything we now see around us : 

 by the other we are admitted a step nearer to the per- 

 ception of the intimate working of those powers which 

 maintain the material universe as it stands, and the laws 

 they oDservc* 



