The Depths Of Old Ocean

A correspondent of the London Times, writiug from Japan, after nis viait to the Admiralty Inlands, reporta that the greatest depth found by the Chullanger was between these islands and Japan. It is the deepest trustworthy sounding on record, except two taken off the east coast of Japan, by the United States ship Tuscarora. The Challenger found depths of 4,575 and 4,475 fathouis (six feet to the fathoni), the Tuscarora 4,t4: 4,655 fathonis. These soundiugs rtpreseut depthB of from h've to ñvo aud onefourth miles. Three out ot tour thermometers i-ent down to these depths by the Ghallanger were crushed by the enoruious pressure of water they had to bear - a pressure of from rive to six tons on the square inch. For three and a half uiiles above the bottoiu the water was a uniform teniperature, 34 1-2 degrees Farenheit. The average temperature at the surface was 82 1 2 degrees. The observations made in this and other points of the Pacific Ocean seem to point, according to the Times' correspondent, to the folio wing law : " That 'globigerina ooze.' a rapidly forming deposit, contaiuing the whole of the abundant carbonate of lime of the ahells of the foramanifera living on the surface and beneath it, and, consequently, consisting of almost pure carbonHte of lime, geuerally occupies depths under 2,000 fathoms in the ocean ; that beyond this depth, the proportion ot the calcareous matter is gradually diminished, and the deposit, whinh now contains a considerable amouut of clay, goes under the name of ' gray ooze ; ' that, at 2,600 tathoms, the calcareous matter has almost entirely disappeared, and we have the purest forin of ' red clay,' a silicato of alumina and iron witta siliceous tests of animáis; tbat from this poiut the ' clay ' decreases in proportion, and the siliceous shell increase, until, at extreme depths, the ' clay ' is represented by a little moro than a red cement binding the shell together. As to the transition from the globigerina ooze ' to the ' red clay,' it is due to the removal of the lime of the globigeriua shells by water and carbonic acid, or in sotne other way ; the apparent disappearance of the ' red clay ' is a fallacy produced by the increased proportion of the siliceous shells.