12G OUR HERITAGE THE SEA 



its flow in whatever direction it is going, without 

 parting with nearly so much of its heat or spreading 

 out as it would have done if it had met with water 

 of only a degree or two lower temperature than itself. 

 Another reason why that great body of warm water 

 should pursue its easterly course in defiance, appar- 

 ently, of the earth's revolution is, that in temperate 

 latitudes the prevailing winds are from west to east, 

 and the warm water being always on the surface is 

 helped along eastward very greatly by this means. 

 Another complication appears in the fact that salt 

 water is heavier than the fresh, and it would seem as 

 if the extra weight of the warm water of the tropics, 

 where so much evaporation has taken place that the 

 salinity thereby is greatly increased, would quite 

 compensate for the increased specific gravity of the 

 cold water, remembering how much fresher the water 

 from the Arctic must be, ice and rain and little 

 evaporation all tending to reduce its salinity. 



But these complex factors balance one another in 

 such a way that the great Gulf Stream flows majesti- 

 cally on towards us, widening out as it gets eastward 

 until about the Azores it divides. One branch of it 

 recurves to the southward to join the parent stream, 

 and the other trends northward, raising the tempera- 

 ture not only over these islands of ours, but actually 

 reaching up into the Arctic seas, and modifying the 

 rigours of their stern climate. But it is with its effect 

 upon us in Britain that we are concerned. It cannot 

 be too strongly insisted upon that but for the Gulf 

 Stream Britain would be an ice-bound desert. In a 

 never-ceasing stream of beneficence this vast oceanic 

 river flows on its unceasing journey, making these 



