THE NEW SCIENCE OF METEOROLOGY 



polar-equatorial maelstrom which manifests itself in 

 the trade-winds to the most circumscribed riffle which 

 is announced as a local storm. And the more the phe- 

 nomena were studied, the more striking seemed the 

 parallel between the greater maelstrom and these lesser 

 eddies. Just as the entire atmospheric mass of each 

 hemisphere is seen, when viewed as a whole, to be car- 

 ried in a great whirl about the pole of that hemisphere, 

 so the local disturbances within this great tide are 

 found always to take the form of whirls about a local 

 storm-centre which storm-centre, meantime, is car- 

 ried along in the major current, as one often sees a 

 little whirlpool in the water swept along with the main 

 current of the stream. Sometimes, indeed, the local 

 eddy, caught as it were in an ancillary current of the 

 great polar stream, is deflected from its normal course 

 and may seem to travel against the stream; but such 

 deviations are departures from the rule. In the great 

 majority of cases, for example, in the north temperate 

 zone, a storm-centre (with its attendant local whirl) 

 travels to the northeast, along the main current of the 

 anti-trade-wind, of which it is a part; and though ex- 

 ceptionally its course may be to the southeast instead, 

 it almost never departs so widely from the main chan- 

 nel as to progress to the westward. Thus it is that 

 storms sweeping over the United States can be an- 

 nounced, as a rule, at the seaboard in advance of their 

 ing by telegraphic communication from the in- 

 r, while similar storms come to Europe off the 

 ocean unannounced. Hence the more practical avail- 

 ability of the forecasts of weather bureaus in the fornu-r 

 country. 



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