12 HALF AN HOUR WITH THE WAVES. 



so, keep up a constant circulation. A few degrees 

 of heat are alone sufficient to produce this mar- 

 vellous result, aided, perhaps, in some cases, by 

 the long-continued action of some such winds as the 

 " trade winds." The general result is that the heat 

 of the tropics causes a circulation of waters towards 

 the poles, and the cold waters of these frigid regions 

 creep along as bottom currents to replace them. 

 Different depths of sea, contiguity of land, pecu- 

 liarities of coast-line, and a hundred other disturb- 

 ing elements, come in to produce a surprising 

 variation, but the general and intended result is the 

 same, nevertheless. Of all these currents, perhaps 

 none is better known than the " Gulf Stream," so 

 called because it takes its name from the Gulf of 

 Mexico, whence it starts on its aquatic journey 

 towards the poles. The revolution of the earth on 

 its axis, fortunately for us, gives what would other- 

 wise be a northerly current an easterly bias, and 

 thus it impinges against British shores, warming 

 the waters and the atmosphere resting on them to a 

 considerable degree. To this agent, more than any- 

 thing else, we owe the genial climate of the south 

 and south-west of England and the west of Ireland, 

 where its influence is most palpably felt. To it, 

 also, is due the fact that Liverpool, although 

 situated one degree more northerly- than St. John's, 

 Newfoundland, has always the Mersey open, whilst 

 the latter trans-atlantic port is blocked up with ice 

 nearly six months out of the year. The recent 



