THE CLOUD REGIOX, ETC. 2C1 



and linrricanes, are nevertheless mucli less frequented by gales of 

 wind, as all furious winds are called, than are the regions on the 

 polar side of these two parallels. 



503. Taking the Atlantic Ocean, north and south, as an index 

 The most stormy of what talvcs pkcc ou othcr watcrs, the abstract logs 

 latitudes. Qf ^}^Q Observatory show, according to the records of 

 265,304 observing days contained therein, that for every gale of 

 wind that seamen encounter on the equatorial side of these two 

 parallels of 30^ N. and S., they encounter 10.4 on the j^ol a r side ; 

 and that for every fog on the equatorial they encounter 83 on the 

 polar side. As a rule, fogs and gales increase both in numbers and 

 frequency as you recede from the equator. The frequency of these 

 phenomena between the parallels of 5° N. and 5^ S., compared with 

 their frequency between the parallels of 45° and 50° N. and S., is 

 as 1 to 103 for gales, and as 1 to 102 for fogs. The observations 

 do not extend beyond the parallels of 60°. It appears from these, 

 however, that both the most stormy and foggy latitudes in the 

 North Atlantic are between the parallels of 45 "^ and 50° ; that in 

 the South Atlantic the most stoimy latitudes are between the parallels 

 of 55° and 60°, the most foggy between 50° and 55°. 



504. How suggestively do these two groups of phenomena re- 

 influenccsoftbeGuifHiind US, ou tho ouc hand, of the Gulf Stream and 

 beariJJcuiSsS" ^^® ice-bearing currents of the north, and, on tho 

 the south. other, of Cape Horn and the antarctic icebergs which 

 cluster off the Falkland Islands !* 



505. Though sea fogs mthin 20° on either side of the equator 

 Sea fogs rare within arc SO rarely seen, yet within this distance, on the 

 ?ed fogl^ '''^''''^"'~ north side, red fogs of "sea-dust" (§322) are not 

 unfrequently encountered by navigators. These can scarcely be 

 considered as coming within the category of sea fogs. The falling 

 of this dust in the form of fog is no doubt owing to those influences 

 (§ 331), the effects of which are so often observable morning and 

 evening in the settling smoke from neighbouring chimneys. The 

 fogs which at early dawni are discovered hovering over om- cities or 



* Captain Chadwick reports, by letter of 30th April, 1860, an iceberg, seen first by 

 him 14th September, 1859, in S. lat. 52^ 25', long. 51^ 8' W. : next, on October 

 10th, in 47° 15' S., 59^ 30' W., by tho Wild Pigeon, Five days later he fell in with 

 it in lat. 45^ 40', long. 58^ 40'. It was last seen 7th November, in lat. 43^44' S., 

 long. 57^ 14' W., by "the British ship "City of Candy." Whetlier this were the 

 same "berg" or not, it shows that icebergs are not imknown to the north of the 

 Falkland Islands, as, indeed, the aqueous isotherm of 60'^, Plate TV., uidicates 

 by its sharp curve about those islands. 



