66 NOTES ON DEEP SEA SOUNDINGS. 



which the " Tusearora" sounded to nearly 28,000 feet, or how 

 otherwise are we to account for the deep stratum of Glacial water 

 in the North Pacific (seeing there can be no fresh connection with 

 the Arctic Ocean), except by the fact that the Antarctic cold 

 water finds its passage northwards all the way past Kamschatka 

 over the deep sea bottom of the Pacific. 



Some very striking facts are related of the depths and bottom- 

 contour of the North Pacific. By sections, on eight lines of 

 soundings, between San Francisco, Cape Flattery, and San Diego, 

 it seems that there is a great similarity in the contour of the 

 bottom and that determined along the western shores of Europe, 

 falling gently and then steeply, as on the west coast of Ireland, 

 with terraces between deep depressions. In the more southern 

 area at 150 miles from San Diego, the depth was 2,117 fathoms, 

 and for nearly 1,000 miles westwards it varied between 2,049 and 

 3,604. About half way to the Sandwich Islands, where it is 2,159 

 fathoms deep, the bottom sinks rapidly to 2,650, and then to 8,000 

 fathoms ; and about 150 miles from Honolulu it rises to 2,488, 

 falling near the Sandwich Islands to 3,023, where they spring 

 from that enormous depth, which exceeds that at the base of the 

 Atlantic Volcanic Islands very considerably. 



Within 50 miles of Hawaii, the water deepens from 206 to 

 1,580 fathoms, and within 100 miles, to 2,418 fathoms. The 

 American half of the North Pacific is, however, more regular than 

 the Asiatic. 



"Westward of Honolulu, the bottom varies from 1,874 falling to 

 3,045 fathoms, and for more than 300 miles continues at about 

 3,000 fathoms ; then at about 1,400 miles west of Honolulu it 

 comes to 1,108 fathoms from the surface. To the eastward the 

 depth increases to 3,262, and keeps nearly the same till 2,275 

 miles from Honolulu, where it rises abruptly from 3,009 to 1,400, 

 then falls to 3,023 ; and so, by alternate abrupt elevations and 

 falls, from 3,000 to 1,500 and 2,173 fathoms. 



The bottom between San Diego and Honolulu consisted of 

 yellowish brown ooze, with fine sand ; but in the shallow portions 

 near the Hawiian Islands, of " whitish-grey sand," apparently 

 disintegrated coral. To the westward, also, the yellowish-brown 

 ooze was uniformly found, but at certain points white coral with 

 lumps of lava, whitish-cream coloured ooze at 1,964 fathoms ) at 

 1,108 and 1,817, white coral ; at 1,613, white coral and sand, and 

 at 2,813, the yellowish-brown ooze. At 2,092 and 2,173 fathoms 

 coral limestone and sand appeared ; at another point, at 1,499 

 fathoms, coral limestone with specks of lava; at another, at 1,712 

 fathoms, coral limestone and sand ; at a third, at 1,700 fathoms, 

 coral limestone and lava ; and on both slopes of Peel Island in 

 the Bonin Group, coral limestone and lumps of lava. 



