The coming of the submarine telephone has certainly lessened the risks of the diver, for he can now talk to the men in the boat and tell them what he wants and how he feels. If anything goes wrong and his lines become entangled, he can inform those at the surface, who can quickly send down another diver to assist him. In comparatively recent days it was necessary to signal by means of the lifeline and air-pipe, a certain number of pulls meaning certain things in accordance with a code in use by all divers. When a diver wished to convey a special message he had to signal for a slate to be sent down, and on the slate he would write what he wanted to convey. It was a slow and cumbersome method which has been rendered obsolete by the submarine telephone, which was invented by that famous submarine engineer, R. H. Davis, the head of Siebe, Gorman & Company. For ages men have dived for sponges and pearls, remaining at most not more than a couple of minutes at the bottom. The ancients were fully alive to the advantages of an invention that would assist men to remain under water for considerable periods, and they were puzzling their heads about diving dresses centuries ago. These early inventions, however, were very crude, one being a sort of barrel with holes through which the arms could be passed, another a metal cylinder which covered the head down to the waist where it fitted into leather breeches. Very strange and wonderful they appear to modern eyes. No less strange and decidedly more wonderful is the up-to-date diving dress which has grown out of the invention of Augustus Siebe in 1819. For eighteen years Siebe experimented with his first type of diving dress before he achieved, in 1837, the form of dress which is closely followed to-day. Various people have added improvements, but Siebe’s form of dress is the one in common use, and the firm of Siebe, Gorman & Company which he founded to supply his diving dresses are to-day the greatest submarine engineers in the world. Inventors have for long been concerned with the problem of a diving dress that will allow a diver to go to any depth without danger. The greatest risk of course, is that he will be crushed to death by the pressure of the water, and to overcome this danger more than one man has invented an all-metal diving dress with flexible joints. In appearance these diving dresses seem cumbersome, and the diver looks more than ever like a knight in armour.