MOORE'S MELODIES. 



the observer predominates so much over the reflected rays'which 

 form the image of his face, that this image ceases to be sensible ; 

 but when by surrounding the basin with a sheet or cloth, all light 

 proceeding from the window is excluded, no light arrives at the 

 eye of the observer except the rays which form the image of his 

 face, which image is therefore distinctly perceivable. 



The basin of water may also be instructively applied to illus- 

 trate experimentally the results consigned to the above table by 

 Bouguer. If it be placed on the floor or table between the observer 

 and the window, the observer standing at a considerable distance 

 from the basin, the rays proceeding from the window will be 

 strongly reflected from the surface, and a vivid image of the 

 window will be perceived in the usual inverted position in the 

 water. As the observer approaches it, the basin at the same time 

 being moved nearer to the window, the obliquity of the incident 

 rays to the surface of the water is gradually diminished, and the 

 vividness of the image will be found to decrease in a much more 

 rapid proportion, until at length the obliquity is so far diminished 

 that the image becomes altogether insensible. 



Whether a reflection under any supposable conditions sufficiently 

 vivid to justify the ancient fable of the Dog and the Shadow is 

 probable, may be questioned, and we do not quarrel with some of 

 our readers who affirm this. We admit that the expressions used 

 by us in paragraph 18, p. 91, vol. 7, may have been too strong if 

 they are understood to imply that in no supposable case could any 

 image whatever be perceivable. We think nevertheless that a 

 dog, looking into a pond with meat in his mouth, the surface 

 of the pond being necessarily exposed to the broad light of day, 

 would not be likely to mistake the exceedingly faint reflection of 

 the meat for another and preferable piece of that aliment. 



8. In one of his Irish Melodies, so familiar to all lovers of poetry 

 and music, Moore has the following lines 



" Oh ! had we some bright little isle of our own, 

 In a blue summer ocean far off and alone, 

 Where a leaf never dies in the still blooming bowers, 

 And the bee banquets on through a whole year of flowers ; 

 Where the sun loves to pause 



With so fond a delay, 

 That the niglit only draws 

 A thin veil o'er the day ; 



Where simply to feel that we breathe, that we live, 

 Is worth the best joys that life elsewhere can give." 



Now this is good poetry, but bad science. An " isle " in which 

 " a leaf never dies," and in which the flowers bloom through the 



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