For recovering metal objects, such as anchors accidentally lost in dock, there is the electric magnet. Among other inventions for seeing on the seabed and recovering lost treasure is the hydroscope of the Italian, Cavaliere Pino. The hydroscope is a floating chamber, from which depends a series of steel pipes that may be extended or shortened at will, just like a telescope. The pipes terminate in a chamber with observation windows made of stout glass, and a man sitting here can observe the whole seabed round about, provided the water is clear, while the hydroscope is being slowly towed along on the surface. [Illustration: WHEN A SHIP OVERTURNS ON QUICKSANDS, THE SALVORS ERECT GREAT LEGS ON THE HULL, AS SHOWN HERE, AND TAKE STRONG STEEL CABLES FROM THE MASTS OF THE WRECK OVER THE TOPS OF THESE LEGS AND HAUL ON THEM UNTIL THEY DRAG THE SHIP UPRIGHT] The hydroscope has done some good work, and by its aid one wreck was raised in five hours after salvors who had been working on it for months had declared that the craft was lost for ever. It was this Italian invention that the Japanese used in clearing the sunken Russian fleet from the bottom of Port Arthur after the termination of the Russo-Japanese War in 1905. A similar invention worked out by a Mr. Williamson has resulted in some extraordinary underwater cinema films being secured. The War led to a big development in the use of compressed air for raising wrecks, divers sealing up all the apertures in the tops of the wrecks with concrete to imprison the compressed air, which was then pumped into the ship until enough water was expelled to enable her to float. The War also hatched a crop of cranky salvage ideas that gave some of the salvage experts one or two happy moments. One such moment was just after the War, when an American walked into one of the British shipping departments and requested to be allowed to salve a ship in order to demonstrate the efficiency of his new method. The officer to whom the stranger went was courteous, listening attentively to the American’s demand, and inquiring at last which ship of the few hundreds sunk round our coasts he would like to demonstrate on. “Any one!” said the American. “I don’t mind. The bigger the better. What about the _Lusitania_?” “She’s rather deep,” it was suggested. “That doesn’t matter. It makes no difference to me what the depth is,” came the easy reply. The officer put a few questions, and then learned that the stranger designed to use a submarine, which was to fire torpedoes right through the _Lusitania_, each torpedo carrying with it a steel cable. These were to be picked up at the other side and taken to the surface, and then the wreck was to be dragged bodily out of the depths! That scheme to salve a ship by first of all smashing a series of holes through her hull with torpedoes did not commend itself to the British expert. It was, indeed, quite impracticable.