80 CRUISE OF STEAMER COR WIN IN" THE ARCTIC OCEAN. 



in several places, but that discovered by Kotzebue is much the larger. This is about half a mile 

 in length, and although its exact width is not known, it may safely be assumed to be not less than 

 300 feet. At about 400 feet back from the edge of the cliff the ground rises quite abruptly for 80 

 or 100 feet, and changes from the springy, mossy covering to a solid mass of earth and stones, and 

 in several places large bosses of lichen-covered granite are exposed to view. Although but 2 

 feet beneath the surface, in no place is ice exposed on the top. The layer of mossy turf covers it 

 as evenly as if laid on by man to protect it from the sun's rays. That it owes its existence now 

 to this covering of moss I have no doubt, but its origiu is not so clear. The grass referred to by 

 Kotzebue grows along the edge of the cliff, and on all irregularities on the face of the ice where 

 the soil from above has been undermined by the melting and falling over, has lodged. Consider- 

 ing its cold foundation and the shortness of the season, the growth of this grass is almost phe- 

 nomenal. Specimens collected by us, growing on a mere handful of soil on the very face of the ice 

 cliff, were 4 feet long, and when dry emitted the fragrant odor of fresh, new hay. 



Ice formations, in many respects similar to that at Elephant Point, occur in various parts of 

 the northern regions, both in America and Siberia, wherever the frozen subsoil is found. This, 

 according to Baer, is coincident with the isotherm of 32° Fahr., and its thickness increases in 

 proportion as the mean temperature of the locality falls below that degree, its unlimited descent 

 being checked by the interior heat of the earth. The extent and thickuess of this frozen substra- 

 tum, whether increasing or decreasing, and to what extent affected by local causes, are interest- 

 ing subjects of inquiry. The thickness of the frozen mass has been measured in various parts 

 of the north by boring. At Yakutz, Siberia, latitude about 62° and mean annual temperature 

 14°, the ground was found frozen to a depth of 382 feet. At Fort Simpson, on the Mackenzie 

 River, in nearly the same latitude as Yakutz, the mean annual temperature '25°, the frozen sub- 

 stratum was found to terminate at 17 feet from the surface; and at the close of the summer of 

 1837 the surface was found to be thawed to a depth of 11 feet, leaving only 6 feet of ground 

 frozen. So far there appears nothing remarkable in the frozen substratum, it being controlled 

 principally by the mean annual temperature of the locality and the internal heat of the earth. 

 But why this frozen substratum should occur at certain places in the form of pure ice does not 

 appear so clear. Whether these ice masses are fragments of the original ice sheet which over- 

 swept the polar regions, or are formed by the waters from the melting snow draining through the 

 soft, light mosses which form the tundra, is a matter for scientific investigation. The presence of 

 fossil remains of extinct species of animals in some of the Siberian ice masses points to the suppo- 

 sition that they have existed for many thousands of years, while some of the ice examined by us 

 near Elephant Point showed unmistakable signs of having been formed bj T the melting snow filter- 

 ing through the surface covering. The mass, though many feet in thickness, was composed of fine 

 strata of ice, some pure and free from vegetable matter, and some so filled with decayed moss as 

 to present more the appearance of frozen earth than ice. Upou being melted, however, it was 

 found to contain but a small amount of vegetable matter, which had a rank, disagreeable taste 

 and smell. This peculiarity was first attributed to the presence of animal matter, but, on exami- 

 nation with a microscope, revealed nothing but the remains of the same species of plants which 

 formed the covering of the whole. A number of wedge-shaped pieces of ice found in the banks 

 around Eschscholtz Bay were probably formed by a small crack in the ground filling with snow 

 and ice, and continuing to enlarge under successive changes from freezing to thawing. 



While making investigations in the vicinity of Elephant Point, Mr. Nelson discovered the 

 remains ot' a beaver dam at one end of the ice cliff, which gave rise to a good deal of speculation 

 and discussion on board as to whether this particular body of ice was not originally a lake; and 

 indeed, considering the habits of the beaver, it is difficult to account for the presence of this dam 

 upon any other hypothesis. The dam was in a good state of preservation, the wood plainly showing 

 the marks of the animals' teeth. It is readily seen how the laud forming the north shore of the 

 lake may have been washed away, and the ice exposed, by the water from the Buckland and other 

 rivers, which discharge into Eschscholtz Bay. The shallowness of the bay, aud the difference 

 in the height of the cliff, on its opposite sides, show that a large amount of washing away has 

 taken place. The moss and grass covering the surface of the ice are also easily accounted for. 



