66 VOYAGE TO THE POLAR SEA. July 



south for about a quarter of a mile before it can force 

 a passage for itself. The debris brought clown by the 

 torrent is being deposited on the land side of the ice 

 wall as a raised beach, and it apparently accumulates 

 as readily above ice as above gravel. Wherever it 

 does so to more than about a foot in thickness — the 

 limited depth of the summer thaw — there the ice must 

 remain and become a component part of the raised 

 beach/ 



Dr. Ninnis, at Discovery Bay, on the 23rd of June 

 succeeded in sinking a shaft, five feet deep, at a 

 position twenty feet above the sea-level, and about fifty 

 yards inshore, in order to lay an earth thermometer. 

 After cutting his way through four feet of fragments of 

 rock and pebbles, he came to a layer of solid fresh- 

 water ice, into which a hole was picked for a depth of 

 one foot without reaching the bottom of the stratum 

 of ice. 



' While the formation of a raised beach inside of 

 the ice-formed compact sea-wall stretching along the 

 shore is very evident, it is difficult to explain why, with 

 a gradual and continuous rise of the land, such ancient 

 formations are afterwards met with as a series of 

 steps ; but as the height of each step increases, and the 

 number decrease with the increasing steepness of the 

 shore, probably the beaches now exposed are only 

 that part of the original accumulation not carried 

 down to a lower level or worn away by the weather. 



' In addition to the boulders and debris which fall 

 from the cliffs during the thaw, and those washed down 

 by the summer torrents, which by collecting inside of 

 the ice-wall form a raised terrace with a steep drop to 



