Ice-Cliffs on the Kobuk River 113 



rested. I gathered some of the sticks from the nest. They were all 

 alders, watersoaked, and soft enough to be easily picked to pieces 

 with the finger nail." 



2. ice-cliffs on the kobuk river 



[Exploration of the Kowak (Kobuk) River. Science, Dec. 19, 1884, p. 

 55I-] 



Abstract of exploration on the Kowak or Kuak River of Alaska, 

 made during the season of 1884 by a party under Lieut. Cantwell, 

 U. S. steamer Corwin, Capt. Healy. 



" July 12, 1884. At half past two p. m. a series of ice-cliffs, like 

 those of Eschscholtz, was observed, composed of a solid mass of ice 

 extending three-quarters of a mile along the left bank, covered by a 

 thin layer of dark-colored earth, and rising to a height of a hundred 

 and fifty feet. Trees were growing on the surface. Up to this 

 point, and for some distance farther, not a single stone or pebble was 

 to be seen, and the silence was frequently disturbed by the fall of 

 large masses of the soft earthy banks vmdermined by the strong 

 currents. * * * At half past four p. m. (July 24th) a remarkable 

 clay bluff, three-quarters of a mile long and a hundred and fifty feet 

 high, was reached on the left bank of the river. Quantities of mam- 

 moth tusks were observed in this clay and its debris where under- 

 mined by the stream." 



[Cruise of the Revenue Steamer Corwin in the Arctic Ocean in the 

 Year 1885. Washington, 1887, p. 48. A Narrative Account of the Explora- 

 tion of the Kowak River, Alaska. By Lieut. John C. Cantwell.] 



" One of the most remarkable, in fact the only remarkable feature 

 of the lower river, is the ice formation in the high black bluffs. The 

 recent heavy rains had caused the river to rise to an unusual height, 

 and I observed in many places where the erosion of the flood had 

 exposed vast masses of ice, which had escaped my notice formerly. 

 Change is the order of the day here, and it is no uncommon thing to 

 see, soon after a flood or freshet in the river, masses of earth, upon 

 which trees thirty or forty feet high have grown, suddenly break 

 away and fall with a tremendous roar into the river. I obtained 

 sketches and photographs of these broken bluffs, but no picture can 

 adequately portray the feeling of utter desolation which this destruc- 

 tive work of the ever-rushing river conveys. 



" The constant falling away of the soft earth, leaving the solid 

 ice bare in many places, has given rise to many curious and fantastic 

 formations. 



