General Introduction 



cause a valued heritage to be disprized. Triumphs 

 to us inconceivable doubtless await the centuries 

 to come, but there will remain as the inalienable 

 glory of to-day that to the old question, What is 

 truth ? it first gave not the old answer, whatso- 

 ever has been so considered, but whatsoever can 

 be proved. 



In that science has in our age demonstrated 

 what hitherto was only suspected, that the uni- 

 verse has an order intelligible to the very 

 core, it has achieved the religious work of 

 displaying Nature as the manifestation of Su- 

 preme Intelligence, not external to it, but imma- 

 nent in it. What though that order be as yet 

 little understood; the diameter of human ignor- 

 ance unmeasured ! Therein is opportunity and 

 incitement for every man with heart and brain to 

 add to knowledge all he may. 



In the series of little books here offered to the 

 public many of the recent triumphs of invention, 

 discovery and exploration are narrated by the 

 men who won them for the world; in other cases 

 a summary of progress has been borrowed from 

 the pages of a careful historian or expositor. 

 A reader who has neither a telescope nor a 

 microscope at command may, nevertheless, be 

 glad to learn something of their revelations. 

 He may have no skill in the use of a test tube 

 or the electric furnace and yet keenly enjoy 

 hearing a chemist recite the new conquests of the 

 laboratory. And in whatever walk of science 



