I I 6 SEA AND LAND 



pressed the profit arisini;- from the fact tliat water expands, in 

 freezing, too far for patience to endure ; to show, in a word, 

 the list of considerable disadvantages which arise from this 

 law, which serve indeed, in some part, to countervail the 

 blessings it brings to us. In his argument he would have to 

 depend in the main upon the dangers which arise from the ice 

 which drifts from either Pole into the parts of the sea which 

 ships need to traverse, bringing with them an atniosphere of 

 fog, which, rendcM'ing the floating islands almost invisible, 

 adds much to the risks of navigation. These ice-masses not 

 onh' endanger vessels, but they chill the waters of the sea in 

 such a measure that, l)y the cold and misty air which sweeps 

 thence upon the land, extensive regions, like the island of 

 Newfoundland, are made unfit for agriculture. These migra- 

 tions of icebergs are nianifestly due, in the main, to the fact 

 that ice floats ; if it sunk, whatever other costs this condition 

 entailed, there would be no wandering ice-fields in the seas. 



To understand the conditions which lead to the existence, 

 even in midsummer, of fioating islands of ice within the 

 warm nortliward-s(,-tting waters of the Gulf vStream, it is neces- 

 sary for us to consider many facts concerning the natural 

 history of ice, and the physical condition of the regions from 

 which these bergs are derived, as well as that of the districts 

 through which they journey to the central portions of the 

 North Atlantic; fortunateh' for our purpose, all these facts 

 are very interesting, and some of them are of the most pictur- 

 csc[ue features which the aspects of this world afford. The 

 biography of an iceberg brings us in contact with the frozen 

 regions about the Poles, and with the marvellous ocean cur- 

 rents which transport the tropical waters to those regions, 

 and with those other streams which send, in return, waters of 



