DIRK GERRITZ ARCHIPELAGO. 181 



only twenty feet in the lower. The bed of the sea 

 round this island seems rather irregular, if Ross's sound- 

 ings to the east of Snow Land and Seymour Island are 

 compared. At a distance of about five miles from the 

 coast they give only 145 feet, while at a distance of three 

 furlongs from the ice wall at the south of Snow Land 

 it was over 325 feet ; somewhat to the west and in the 

 line of Admiralty Bay 480 to 590 feet, and fifteen miles 

 south of Snow Land it was already 980 feet. All these 

 irregularities in the structure of the sea bottom might be 

 referred to volcanic phenomena, if indeed they are not 

 attributed to glacial action originating in heavier masses 

 of ice. Ross did not visit the coast at the foot of Mount 

 Haddington, but the dark masses of which it is composed 

 seemed to him to indicate a volcanic origin ; this opinion 

 was strengthened by the outlines of the mountain and its 

 superimposed layers of fused stones. The stones taken 

 from the crops of penguins certainly belonged to eruptive 

 matter, and only one specimen of granite is mentioned by 

 McCormick the geologist and superior medical officer 

 of the Erebus. Seymour Island, forming the northern 

 continuation of Snow Land from which it is separated 

 by the six to nine feet deep sound, is indisputably of 

 volcanic structure. According to Ross, the island may 

 be assumed to consist entirely of stone and volcanic 

 matter recently ejected ; the surface is described as 

 consisting of a deep brown lava with the characteristic 

 corrugated conformation of the smooth mass on the top. 

 Larsen's opinion, which 'fifty years later coincided with 

 that of Ross, is supported by the circumstance that the 

 island was free from snow ; the dark colour of the rocks 

 moreover led him to conclude that the island had recently 

 been in a state of eruption, as the icebergs attached to 

 the island were seen to be discoloured at the top and the 

 side adjacent to land. No centre of eruption, however, 

 has as yet been found. Seymour Island is remarkable as 



