Caleb again swam carefully around the stone, opened his arms, and inflating his dress rose five or six feet through the green water, floated over the huge stone, and grasping with his bare hand the lowering chain by which the stone hung, tested its strain. The chain was as rigid as a bar of steel. This showed that the stone was not fully grounded, and therefore dangerous, being likely to slide off at any moment. The diver now sent a telegram of short and long jerks aloft, asking for a crowbar; hooked his legs around the lowering chain and pressed his copper helmet to the chain links to listen to Captain Joe’s answer. A series of dull thuds, long and short, struck by a hammer above—a means of communication often possible when the depth of water is not great—told him that the crowbar he had asked for would be sent down at once. While he waited motionless, a blackfish pressed his nose to the glass of his face-plate, and scurried off to tell his fellows living in the kelp how strange a thing he had seen that day. A quick jerk from Lacey, and the point of the crowbar dangled over Caleb’s head. In an instant, to prevent his losing it in the kelp, he had lashed another and smaller cord about its middle, and with the bar firmly in his hand laid himself flat on the stone. The diver now examined carefully the points of contact between the boulder and the hanging stone, inserted one end of the bar under its edge, sent a warning signal above, braced both feet against the lowering chain, threw his whole strength on the bar, and gave a quick, sharp pull. The next instant the chain tightened; the bar, released from the strain, bounded from his hand; there was a headlong surge of the huge shadowy mass through the waving kelp, and the great block slipped into its place, stirring up the bottom silt in a great cloud of water-dust. The first stone of the system of enrockment had been bedded! Caleb clung with both hands to the lowering chain, waited until the water cleared, knocked out the Lewis pin that held the S-hook, thus freeing the chain, and signaled “All clear—hoist.” Then he hauled the crowbar towards him by the cord, signaled for the next stone, moved away from the reach of falling bodies, and sank into a bed of sea-kelp as comfortably as if it had been a sofa-cushion. These breathing spells rest the lungs of a diver and lighten his work. Being at rest he can manage his dress the better, inflating it so that he is able to get his air with greater ease and regularity. The relief is sometimes so soothing that in long waits the droning of the air-valve will lull the diver into a sleep, from which he is suddenly awakened by a quick jerk on his wrist. Many divers, while waiting for the movements of those above, play with the fish, watch the crabs, or rake over the gravel in search of the thousand and one things that are lost overboard and that everybody hopes to find on the bottom of the sea.