STEERING A SHIP BY SOUND.

Ashburton Guardian, Volume XLI, Issue 9430, 29 January 1921, Page 3

STEERING A SHIP BY SOUND.

With his pilot-house windows screened by heavy canvas, which effectively shut out the surrounding view, Commander Norton, of the American destroyer Semmes, guided only by sounds from electrical waves thrown out by a submerged cable, piloted his vessel from near the Ambrose lightship for 16 miles along the channel of New York harbour to Port Lafayette, m the narrows. The feat marked a successful test of an invention by which it is hoped to enable liners and warships to make their way tip the harbour to their Hudson or East River docks or anchorages, m defiance of the densest of foga or the darkest of nights made denser I by falling snow. The cable at the, bottom of the fairway was charged 1 from the fort. Two electric coils had \ been set above the waterline of the Semmes on each side of the bow, and wires extended from them into an amplifier on the bridge. From the amplifier telephone receivers had been carried to various parts of the vessel, and, with these clamped to their ears, several persons heard the sounds given off by the cables. As the destroyer approached the latter at a 16-knot speed a faint clicking of the code word, "Navy," was heard. It grew louder first on the port side and then on the starboard side as the vessel steered to left; or right of the cable, and Commander Norton had no trouble m following the line through the sounds, which increased m volume, or frew fainter, according to whether the emmes was headed along it or from it.