18 Supposed Connection of Meteoric Phenomena, 



wind. Thus, in the winter of 1831, during six weeks, at 

 London, a n. and n.e. wind thawed, while a s.s.w. wind froze. 

 That there are various currents of air frequently travelling in 

 counter directions to each other, has been often remarked.* 

 On Sept. 18. 1834, 1 had a singular proof of this : the surface 

 wind blew lightly from the south-east, as shown by the smoke 

 of a cottage seen from a window. Behind the cottage rises 

 the hill called Lytchet Beacon (about 54*0 ft. above the level 

 of Poole harbour) ; a smoke from fires on it travelled due 

 south ; above the hill, and at a considerable height in the air, 

 there were streaks of sea-fog rapidly moving to the north ; 

 while, over all, the light specks of clouds, in the lofty sky, 

 were quietly stealing along from the west. On the 19th, at 

 daybreak, the fog occupied the whole landscape, and was so 

 thick as to hide all objects a few yards off. The south wind, 

 therefore, descended in level. Winds high up in the atmo- 

 sphere often transport matters in a direction totally contrary 

 to what may be, prima facie, imagined. Ashes from Vesuvius, 

 on Dec. 6. 1631, fell in Greece and 100 leagues from the 

 coast of Syria f (Redfield), when there was no wind at the 

 time. In 1812, St. Vincent threw ashes to Barbadoes, sixty 

 or seventy miles to the east, and 1 00 miles beyond, directly 

 in the teeth of the trade-wind, which then blew from the 

 west. [Id. See also Dr. Hancock's Paper, Phil, Mag., 3d 

 series, iv. 343.) In the same year ashes fell on the deck of a 

 packet bound to Brazil, when 1000 miles from any land. [Red- 

 field.) A friend of mine informs me, that, when sailing through 

 the Cape de Verd Islands, in June, 1822, the rigging was 

 suddenly covered with a brownish dust, which appeared like 

 triturated pumice, and had a sulphuric smell. As the wind 

 was n.e., I am inclined to consider this dust not volcanic, but 

 transported sand from the African desert, attracted, possibly, 

 by heat from Fogo (one of the Cape de Verds), or by some 

 eruption at sea to the southward, as in the case of Etna, 

 May, 1830. (VI. 298.) Now, it can make little difference 

 in the effects, whether a current of cold air descends to the 

 surface of the earth, or a heated column ascends J; nor can it 



* Mr. Forster speaks of four currents of air on Oct. 25. 1809. (Re- 

 searches on Atmospheric Phenomena, p. 343.) 



-f Dr. Daubeny gives the date of the eruption in 1631, December 16. 

 The date of the shower of ashes I take from Badily's account of it. 

 (Polehampton, iv. 161.) Vesuvius was, therefore, in eruption before De- 

 cember 16. Ashes, also, from Hecla, fell on a vessel seventy-five miles 

 north of Shetland, and all over Norway, in 1783. 



J Young," in his^ Lectures (i. 704.), considers hurricanes as caused by 

 portions of the upper currents of the air prematurely diverted down ;" and 

 says their course is contrary to the regular trades. Sir J. Herschel, com- 



