364 LEISURE-TIME STUDIES. 



particular way of expressing the brilliance and lustre of the 

 rainbow hues, but it leads to no idea of causation whatever. 

 Byron has even a finer simile, when in " The Bride of 

 Abydos," he says : 



" Be thou the rainbow to the storms of life ! 

 The evening beam that smiles the clouds away, 

 And tints to-morrow with prophetic ray ! " 



Here the metaphor is plain, elegant, appropriate. No critic 

 would deny, I apprehend, that this is a good example of the 

 deftest touch of the poet, or that it is fairly to be esteemed a 

 form of the truly poetic interpretation of nature. Yet withal 

 you must rest content with the poetic thought. There is no 

 attempt to go further, to relate the rainbow to any other 

 phenomena of nature, or even to its own causation. There 

 is, moreover, in my humble opinion, no need whatever for the 

 expression of any such relationship ; for you receive and re- 

 cognise the poetry of Byron's thought. You see that his me- 

 taphorical interpretation of the rainbow as an augur of hope 

 and peace is true and applicable, and you demand nothing 

 further. The thought pleases and charms, and you are con- 

 tent. You do not expect that the poet's expression should 

 lead you directly or indirectly into the midst of physical 

 science in general, or into the study of colour, light, and heat 

 in particular. Whether or not you may know that Newton 

 showed a rainbow "to be due to the unequal refrangibility 

 of elementary rays," is nothing to the purpose. Not that I 

 maintain for one moment that, provided you knew the exact 

 physical explanation of the rainbow, you would on that 

 account enjoy either the sight of the bow or the poet's 

 allusion to it, one whit the less. I shall strive, on the con- 

 trary, to show you presently that such scientific knowledge, 

 so far from destroying the poetic feeling, may, when rightly 

 used, encourage and supplement the poetic interpretation of 

 nature in its best and truest aspects. When we know that 

 the rainbow is not "based on ocean" and does not "span 

 the sky," as Byron tells us, we do not on that account enjoy 



