MOORE'S MELODIES. 



polar distance. Now the sun's polar distance at Midsummer is 

 66|, and in order that its depression at midnight should not 

 exceed 18, the latitude of the place must at least be equal to 

 66|, diminished by 18, that is, 48. 



It follows, therefore, that an entire night of twilight can only 

 take place at latitudes higher than 48 1. But to produce the 

 effect expressed by the poet, a twilight should be maintained 

 much stronger than that characterised by the scientific sense of 

 the term. A twilight which would be only a " thin veil drawn 

 over the day," would be such as can be only witnessed in lati- 

 tudes like those of Norway and Sweden, the northern parts of 

 Scotland, the Orkneys, &c. 



In tropical latitudes, on the contrary, the celestial pole has an 

 altitude less than 23^, and the diurnal path of the sun makes 

 with the plane of the horizon an angle greater than 66^. After 

 sunset, the sun therefore descends very rapidly, and the more 

 rapidly the nearer the place is to the line. At the line itself the 

 sun attains the depression of 18 in about seventy-two minutes 

 after sunset ; and although the twilight in the scientific sense of 

 the term would not terminate till then, it comes to a close much 

 sooner in the poetic sense of the " veil drawn o'er the day." In 

 short, an almost sudden darkness succeeds sunset, and, in like 

 manner, sunrise succeeds as suddenly to the darkness of night. 



In a word, the poet, in the beautiful lines cited above, has com- 

 bined incompatible astronomical and climatological conditions. The 

 perpetual summer necessarily infers tropical latitude, while the short 

 and twilighted night infers a high, not to say a polar latitude. 



It would, perhaps, be deemed hypercritical to examine how far 

 the naturalist would justify the poet in his allusion to the industry 

 of the bee in a tropical climate. The honey-bee, which no doubt 

 was the insect alluded to by the poet, is, for the most part, con- 

 fined to ultra- tropical latitudes. Since, however, there are certain 

 species of this insect found in the lower latitudes, it may be 

 admitted that the poet has, at least in this point, a locus standi. 



Having had the pleasure of the personal acquaintance of the 

 author of the Melodies, I once pointed out to him these scientific 

 incompatibilities in his lines. He replied good-humouredly, that 

 it was lucky when he wrote the song that such inconsistencies did 

 not occur to him ; for, if they had, some pretty thoughts would 

 inevitably have been spoiled, since he could not have been brought 

 knowingly to take such liberties with the divinities of Astronomy 

 and Geography. 



10. The allusion and imagery which Moore loved to seek 

 in certain parts of physical science were generally much more 



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