THE ICE OE THE BALTIC. 



47 



carried in the greatest quantity, and approaches most nearly to the 

 equator. Some has even been perceived from Cape Town in 34 



10 O 10 20 30 40 &0 60 30 00 00 



I. Ti istajv d!Ac trihay 



W 



feii; ^sca^ . 



.'Trei^S ..ot. 



I-Amstefdifnty 



C-apricorr 



l.Pr 'nceEchoa 



^ 



I icrfimelen. 



f :r<S&Ver<y:e 



Fig. 17.— Course of Icebei^s in the Southern Hemisphere. 



degrees of south latitude. Thus the Antarctic icebergs are carried 

 about 250 miles nearer the torrid zpne than are the Arctic masses. 



In the inland seas exposed to severe cold, the congelation of the 

 water is produced in the same way as in the ocean ; the phenomena 

 only differ in proportion. Thus the ice of the Baltic is far from pre- 

 senting such a grand spectacle as the ice-fields of the Polar seas, but 

 its mode of formation is known in a much more complete manner ; for 

 during a long series of years, conscientious observers have studied its 

 various changes, from the formation of the first ice to the general 

 breaking up. These researches have proved that after having been 

 formed, the icy bed of the Baltic is subject to the same phenomena as 

 that of lakes, not only in the northern parts of the sea where the 

 water is almost fresh, but near the entrance also where the mass of 

 fluid is still strongly saline. The crevasses in the ice do not differ 

 essentially in their formation from those of Lake Baikal * or the Lake 

 of Constance. They also open with a thundering noise letting a great 

 quantity of water escape, which freezes in its turn and thus increases 

 the thickness of the solid bed. Around the island of Oesel the fissures 

 vary from six inches to more than six feet, and are continued for a 



* See in Vol. I. the section entitled, Lakes. 



