130 Facts in Meteorology. 



3. The general movement or oscillation of an extensive region of 

 atmosphere in the higher latitudes, under the alternately predomina- 

 ting influence of centrifugal action towards the equator, and gravita- 

 tion towards the poles. These extensive oscillations are infrequent, 

 and nearly uniform in their effect on the barometer over an extensive 

 region of country at nearly the same time. 



The highest range in the polar regions observed by Capt. Parry, 

 was 30.86 inches. During a violent storm or hurricane the barome- 

 ter has sometimes fallen below 28 inches. 



The fall of the barometer has no necessary and immediate cqn- 

 nexion with rain, although storms of wind which affect the barome- 

 ter are often attended by rain. It appears from the observations of 

 the Marquis Poleni, that in 1175 instances of falls of rain, the ba- 

 rometer sunk only 758 times, being 645 to 1000. In the United 

 States, the most copious rains sometimes fall during an unusual ele- 

 vation of the barometer. 



Currents and Temperature of the Ocean. 



The conformity of the oceanic movements to those of the atmos- 

 phere, with other analogies in the two fluids, will, perhaps, justify a 

 few notices, which do not belong to the department of Meteorology. 



The most remarkable currents in the ocean are those which con- 

 tinually follow the same direction. These usually follow the course 

 of the great circuits of wind in every ocean, and besides, have a 

 general connexion with each other, so that much of the oceanic fluid 

 is constantly passing from one basin to another. 



The waters of the north Atlantic perform a constant circuit in the 

 parallels between the equator and the banks of Newfoundland, of 

 which circuit the concentrated current of the gulf stream forms a 

 conspicuous part, and in the center of this circuit is situated the 

 great field of floating sea-weed called the grassy sea. Its strength 

 is perhaps aided by the current which passes from the Indian Ocean 

 round the Cape of Good Hope, through the south Atlantic, and 

 which, joining the equatorial current, passes to the north west into 

 the Caribbean sea. 



In the north Atlantic a counter circuit is also formed, which passes 

 near the British islands and the coast of Norway, and enters the 

 polar basin, from whence it returns under the name of the polar 

 current, and passing down the coasts of Greenland and Labrador, 

 carries with it, at certain seasons, the floating ice of the polar re- 

 gions. 



