160 CORRELATION OF PHYSICAL FORCES. 



the astronomer while directing his vision to a different point 

 of space, and disappears when steadfastly gazed at, only to 

 have its position and figure ultimately ascertained by the 

 employment of more penetrative powers, so. the first scintilla- 

 tions of new natural phenomena frequently present themselves 

 to the eye of the observer, dimly seen when viewed askance, 

 and disappearing if directly looked for. When new powers 

 of thought and experiment have developed and corrected the 

 first notions, and given a character to the new image probably 

 very different from the first impression, fresh objects are 

 again glanced at in the margin of the new field of vision, 

 which in their turn have to be verified, and again lead to new 

 extensions ; thus, the effort to establish one observation leads 

 to the imperfect perception of new and wider fields of re- 

 search ; and, instead of approaching finality, the more we 

 discover the more infinite appears the range of the undis- 

 covered ! 



