TO SAFEGUARD SHIPS IN FOG.

Auckland Star, Volume LIV, Issue 131, 4 June 1923, Page 3

TO SAFEGUARD SHIPS IN FOG.

SUBMARINE DETECTOR.

ADAPTED TO PEACE-TIJIE.

An official announcement of tremendous interest to the maritime world is likely to be forthcoming in Paris during the next few weeks to the effect that the famous wartime invention of detecting submarines by using "ultra sonorous" waves, is finally to emerge from the control of the admiralties and be adapted for purposes of peace. It will mean that henceforth the greatest danger of the sea—fog—may be reduced to a minimum. For with this invention at its present stage of development, vessels may be capable of warning each other of their respective positions within a radius of about five miles and long before the sound of the fog sirens can 'be heard. The work of 'bringing the invention to its present stage has been accomplished by Prof. Langevin, of the College de France, who worked with the original inventor, M. Chilowsky, a Russian, for two years during the war. It was Prof. Langevin who in 1917 succeeded in uniting the first apparatus for the emission and reception of ultra sonorous wave signals. Naturally, the naval hierarchy of the Allied Powers strictly reserved that invention for military purposes. The war ended before it could be used in anything more than a trial and since then the admiralties of the different countries have been continuing to study the problem on their own account. In France the Langevin apparatus offeVed too great an interest for the commercial navy not to attempt to make use of it, and within the last few weeks representatives of commercial and maritime interests, both of England and the United States, have been in conference in Paris for the purpose of putting the invention on a commercial basis. At present the Langevin apparatus can direct a mass of waves a distance of five miles ahead of vessels. If there is no response the indication is that the way is clear. But if they encounter obstacles, rocks, icebergs, or submerged vessels, the waves will give forth an echo when striking the object, thus bringing the sound back to the emitting apparatus. The measure of time taken for the echo to return permits the exact distance of the object from the ship to be calculated. However, if the invention will diminish the risks of sea for men it apparently increases the dangers for the animal life of the deep. During recent experiments fish caught in the bounds of the ultra-sonorous waves were killed immediately.