More cables were carried out from the power station to work the air compressors, and, as soon as the divers had made a number of compartments watertight, the salvors began to pump air into the sunken vessel. The air which was pumped in naturally rose. It tried to get away to the surface, but the keel of the battleship, which had been most carefully repaired and made airtight, prevented it from escaping. The air was thus caught, as it were, in a trap. There was no way out for it. It was not strong enough to break through the bottom of the ship, but it was strong enough to press down the water within. As the volume of air increased, the belt which it formed grew in depth until it had forced the water down for a distance of 26 feet below the level of the sea outside, and men were able to enter the bottom of the vessel through an air-lock, work in security in this belt of compressed air, and lighten the vessel by taking out her stores and coals. By the beginning of November, 1917, the salvors occasionally felt the battleship stir slightly beneath their feet. Despite the fact that she was buried deeply in the mud, her bow was showing the slightest of inclinations to rise. The engineer in charge noted this with delight. Barely perceptible as was the movement, it was more than sufficient to encourage him to persevere. Once more the thick oil cropped up to hamper operations and increase the many difficulties. As the water was forced down inside the vessel by the compressed air, the oil was deposited on everything. In most cases this did not matter much, but it was of far-reaching importance when it came to searching for leaks in the hull. The oil so obscured these places that it was extremely difficult to locate them, yet everything depended on their being discovered, for had they been left unstopped they might have let out the air and made it impossible to refloat the ship, or, alternatively, let in the water at a critical time and led to her sinking in such a position that she could never be floated again. Fortunately, the Italian salvage men were able to detect all the leaks and stop them effectively, as the sequel amply proved. [Illustration: AFTER FLOATING FOR TWO DAYS IN DOCK, THE BATTLESHIP WAS COAXED INTO POSITION UNTIL SHE SETTLED WITHOUT ACCIDENT ON THE WONDERFUL TIMBER FRAMEWORK SHOWN HERE. IT WAS A FINE FEAT TO ACCOMPLISH] Critics of the operations pointed out that, should the salvors succeed in floating the battleship upside-down, there was not sufficient depth of water to allow her to be taken across that mile and a half of sea to dry dock. Even if they managed to get her to dry dock, all their work would be wasted, for the battleship floating upside-down would draw at least 50 feet of water, and the dry dock at Taranto was only 40 feet deep. [Illustration: A REMARKABLE PHOTOGRAPH TAKEN FROM AN AIRSHIP OF THE UPSIDE-DOWN BATTLESHIP IN DRY DOCK]