As the tug and sloop passed into the broad water, Medford Village could be seen toward the southeast. Sanford adjusted his marine-glass, and focused its lens on Mrs. Leroy’s country-house. It lay near the water, and was surmounted by a cupola he had often occupied as a lookout when he had been Mrs. Leroy’s guest, and the weather had been too rough for him to land at the Ledge. He saw that the bricklayers were really at work, and that the dining-room extension was already well under way, the scaffolding being above the roof. He meant, if the weather permitted, to stop there on his way home. Soon the Ledge itself loomed up. The concrete men were evidently busy, for the white steam from the mixers rose straight into the still air. An hour more and the windows on the lee side of the shanty could be distinguished, and a little later, the men on the platform as they gathered to await the approaching flotilla. When they caught sight of the big blocks stored on the Screamer’s deck, they broke into a cheer that was followed by a shrill saluting whistle from the big hoisting-engine on the Ledge, answered as cheerily by the approaching tug. Work on the Ledge could now begin in earnest. If Crotch Island was like the back of a motionless whale, Shark’s Ledge was like that of a turtle,—a turtle say one hundred and fifty feet long by a hundred wide, lying in a moving sea, and always fringed by a ruffling of surf curls, or swept by great waves that rolled in from Montauk. No landing could ever be made here except in the eddy formed by the turtle itself, and then only in the stillest weather. The shell of this rock-incrusted turtle had been formed by dumping on the original Ledge, and completely covering it, thousands of tons of rough stone, each piece as big as a cart-body. Upon this stony shell, which rose above high-water mark, a wooden platform had been erected for the proper storage of gravel, sand, barrels of cement, hoisting-engines, concrete mixers, tools, and a shanty for the men. It was down by the turtle’s side—down below the slop of the surf—that the big enrockment blocks were to be placed, one on the other, their sides touching close as those on a street pavement. The lowest stone of all was to be laid on the bottom of the sea in thirty feet of water; the top one was to be placed where its upper edges would be thrust above its splash. In this way the loose rough stones of the turtle’s shell would have an even covering and the finished structure be protected from the crush of floating ice and the fury of winter gales.