ECHO APPARATUS

Nelson Evening Mail, Volume LXI, 9 October 1928, Page 4

ECHO APPARATUS

FINDING THE DEPTH OF THE SEA

An echo-sounding apparatus is now used to ascertain ocean depths. In the last few years navigators have heen extremely interested to see on revised Admiralty charts which are used by seamen of all nations the plotting of unfamiliar sea depths, and the now method is adding greatly to our knowledge of the sea. A few years ago, when tlie°wiro lead apparatus was still being used, the greatest depth which had boon plumbed was five miles, and this, according to the geography- hooks, is the greatest known sea depth. It was clear that in many places the sea was deeper than could he penetrated by the wire, but how much could not he discovered. By the now method there is no' limit to the depths which can he ascertained, and, German, American and Japanese ships are constantly reporting colossal depths. "These are marked on the. Admiralty charts. There was a time when no plottings were made which bad not been backed by a specimen of the hot lom of the sea, hut with the new method there is no need to doubt the aecuraey of the depths reported. The greatest have heen reported by a German survey ship in the Eastern Archipelago. They vary between seven and eight miles. Another German ship has done some extraordinary work in tho South Atlantic, re-charting the whole of the area and totaly revising ideas as to the depths of the ocean and the configuration of tlie land under it.