MOORE'S MELODIES. 



when exposed to the strong light is not sufficiently open to admit 

 the rays of feeble light necessary to produce visual perception, 

 and for some time the surroimding objects are invisible. When, 

 however, the proper muscular apparatus has had time to act upon 

 the iris so as to enlarge the pupil, the rays are admitted in greater 

 quantity, and the surrounding objects begin to be perceived. 

 These phenomena are beautifully expressed by the lines of 

 Moore : 



" Thus when the lamp that lighted 



The traveller, at first goes out, 

 He feels awhile benighted, 



And lingers on in fear and doubt ; 



** But soon the prospect clearing, 



In cloudless starlight on he treads, 

 And finds no lamp so cheering 



As that light which Heaven sheds." 



Nevertheless there is ai point in this which demands some ex- 

 planation. It is implied in these lines that the source of nocturnal 

 illumination is chiefly, if not exclusively, starlight. This has 

 been in a great measure disproved in some memoirs published by 

 Arago in the " Annuaire du Bureau des Longitudes," in which he 

 shows that there must be some other source of nocturnal illumi- 

 nation than that of the stars. On nights, for example, which are 

 thickly clouded there is sometimes a stronger light than on those 

 in which the firmament is clear and serene. From this and other 

 circumstances Arago argues that there must be some power of 

 illumination in the clouds or in the atmosphere independently of 

 the light which proceeds from the stars. This is a point, however, 

 the full development of which would require more space and 

 time than we can spare for it on the present occasion. 



11. In another of Moore's poems we find the following beautiful 

 lines : 



u While gazing on the moon's light 



A moment from her smile I turn'd, 

 To look at orbs that, more bright, 

 In lone and distant glory burn'd. 

 But too far 

 Each proud star, 



For me to feel its warming flame, 

 Much more dear, 

 That mild sphere, 



Which near our planet smiling came. 

 * * * * 



Thus, Mary, be but thou my own ; 



While brighter eyes unheeded play, 

 I'll love those moonlight looks alone, 



That bless my home and guide my way." 



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