THE AGE OF ICE. 



647 



late at m ; tb may show the origin of the block i, which is now going 

 to sea as a buoy. In many cases the icebergs must carry with them 

 stones frozen on the under side, as well as blocks perched on their 

 backs. Dr. Kane speaks of ice-rafts, floating many miles out to sea — 

 tables 200 feet long covered with large angular blocks and bowlders. 



Fig. 5. 



Greenland Glacier shedding an Iceberg. 



Though Greenland is said to be inhabited only upon the south and 

 west coast, there is a record of an early settlement upon the side 

 toward Iceland, with which there has been no communication for 400 

 years. The colony was planted about 1000 a. d., which flourished, 

 and maintained intercourse with its mother-country till the beginning 

 of the fifteenth century. Since that time, owing to the setting in of 

 the arctic current, and the consequent gradual increase of ice upon 

 the coast, the colony became inaccessible, and the records of it disap- 

 pear from history. At various intervals between, 1579, 1751, etc., 

 down to our own time, the intrepid Danes have striven in vain to re- 

 open communication with their lost colony. This emerald coast, with 

 valleys well stocked with reindeer and verdant glades, is now shut in 

 by the pitiless ice-pack, and the fate of its inhabitants ought to excite 

 the interest of the world. It would be very interesting to be informed 

 of the condition of this colony : whether the increasing cold lias en- 

 larged the glaciers so as to push the dwellings out to sea, or whether 

 the habitations are still standing, and a population has sprung up who 

 know of the outside world only by tradition* 1 



JLake-Basins. — A strong argument for the former existence of gla- 

 ciers over the northern regions comes from the excavation of basins 

 from the solid rock for the reception of lakes. The country most 

 traversed by the ice agency abounds in these rock-hollows. It is very 

 evident that the glacier is the only agency which can well be called 

 upon to explain these phenomena. Running water excavates only on 

 a descending plane. Sea-water acts upon its level, while the glacier 

 requires only a pressure from behind to enable it to ascend mountains. 

 The upward movement of the ice is shown by the striae to have been 

 exceedingly common. 



The glacier grinds hardest where the steeper slope is exchanged for 

 a less inclination of its rocky bed ; the tendency of this action is to 



1 Geological Magazine, vol. x., p. 541. 



