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globule of the same dimensions as the perforation might produce 

 a similar halo. He found them to vary from the 5000th to the 

 .50,000th part of an inch in diameter. When the hale approach- 

 es nearest to the body, the largest globules are floating, and there- 

 fore the atmosphere is surcharged with humidity. Hence the 

 justness of the vulgar remark, that a dense halo close to the moou 

 portends rain. 



The elevation of coasts, ships, and mountains, above their 

 usual level has long been knewn under the name of looming, 

 and the name 'mirage has been given by the French to the same 

 ^phenomena. The curious spectacle often witnessed at the straits 

 of Messina called the Fata-Morgana, belongs do the same class of 

 .optical phenomena. One of the most interesting cases on record 

 .was witnessed by Opt. Scoresby, in the Arctic sea. WhUe-nav- 

 jgating the Greenland sea on the .28th of June, 1820, he observed 

 about eighteen or nineteen sail of ships .at .the distance of from 

 <ien to fifteen miles. He saw them from the mast-head begin- 

 ning to change their form, one was drawn out or elongated in a 

 s/ertical plane, another was contracted in the same direction, one 



fcad an inverted image immediately above it as at a; and two at h 

 and c, had two distinct inverted images in the air; along with 

 these images there appeared images of the ice, as at b and c, in 

 two strata, the highest of which had^n altitude of about fifteen de- 

 grees. In a later voyage performed in 1822, he saw his father's 

 hip when below the horizon. *' It was" says he, " so well de- 

 X-n.ed that I could distinguish by a telescope every sail, the genera 



