Nothing could illustrate these two points better than the story of how the Baltic found the Republic in the year 1909, in a dense fog off Nantucket Lightship, when the latter was drifting helplessly after collision with the Florida. The Baltic received a wireless message stating the Republic's condition and the information that she was in touch with Nantucket through a submarine bell which she could hear ringing. The Baltic turned and went towards the position in the fog, picked up the submarine bell-signal from Nantucket, and then began searching near this position for the Republic. It took her twelve hours to find the damaged ship, zigzagging across a circle within which she thought the Republic might lie. In a rough sea it is doubtful whether the Republic would have remained afloat long enough for the Baltic to find her and take off all her passengers. Now on these two occasions when wireless telegraphy was found to be unreliable, the usefulness of the submarine bell at once becomes apparent. The Baltic could have gone unerringly to the Republic in the dense fog had the latter been fitted with a submarine emergency bell. It will perhaps be well to spend a little time describing the submarine signalling apparatus to see how this result could have been obtained: twelve anxious hours in a dense fog on a ship which was injured so badly that she subsequently foundered, is an experience which every appliance known to human invention should be enlisted to prevent. Submarine signalling has never received that public notice which wireless telegraphy has, for the reason that it does not appeal so readily to the popular mind. That it is an absolute necessity to every ship carrying passengers--or carrying anything, for that matter--is beyond question. It is an additional safeguard that no ship can afford to be without. There are many occasions when the atmosphere fails lamentably as a medium for carrying messages. When fog falls down, as it does sometimes in a moment, on the hundreds of ships coasting down the traffic ways round our shores--ways which are defined so easily in clear weather and with such difficulty in fogs--the hundreds of lighthouses and lightships which serve as warning beacons, and on which many millions of money have been spent, are for all practical purposes as useless to the navigator as if they had never been built: he is just as helpless as if he were back in the years before 1514, when Trinity House was granted a charter by Henry VIII "for the relief...of the shipping of this realm of England," and began a system of lights on the shores, of which the present chain of lighthouses and lightships is the outcome.