SOUND v. WIRELESS

Radio Record, Volume I, Issue 40, 20 April 1928, Page 15

SOUND v. WIRELESS

wo fog-signalling stations off the German coast, one at the mouth of the Ems and the other on the Meuse, are using a new system of warning vessels by which a ship can tell how far it is from shore. It is done by making a sound travelling through the water race a wireless signal! The sound from a submarine bell travels at about 1860 yards a second

DERUELIELEES SUG REAREGRAER SOUTER ETD EPE TEST AETRSEE COTE EC TEETER through the water, but a wireless signal, travelling with the speed of light, takes (so little time that it need not be counted. The operator on the ship thus hears the wireless signals instantly and the submarine signals later. ‘he wireless signals are recorded as dots, which are marked on a travelling paper ribbon, so mally a second, and the operator has merely to count how many dots appear between the beginning of the wireless signal and the hearing of the sulmarine hell to find how far away he is. , Two lightships have been eduipped to- test submarine sigualling, using an_ under-watcr oscillator which yibrates 1050 times a minute. The signals will he picked up by ships provided with submarine telephones or hydrophones.