In the afternoon, Olaf had the sharpie (which is a flat sharp-nosed boat with two masts) ready with a little dingey tied on behind, and when the tide rose the party went aboard. First he headed well out into the bay, and then tacked to enter the river where the channel was deepest. The river, which was the same that ran through the woods above the Farm, was caught in a corner to make the mill-pond, and finally escaping, ran along for many miles until the bay opened its wide arms to receive it. "What are those birds over there?" cried Nat, pointing toward the outer beacon. "Some look like white Crows, and the others go zigzag like big Barn Swallows. Are there any such things as water Swallows, Uncle Roy?" "Not exactly--both the birds you see belong to the Swimmers. The larger ones are Herring Gulls, and the smaller ones are Terns. But your guess is not a bad one, for all Terns are also called Sea Swallows, because of their dashing flight. Both Gulls and Terns nest on Gull Island, where Olaf is going to take us some day when the water is smooth. The storm has driven some of them into the bay, where they do not usually come until later in the year; but in winter great flocks of Gulls live about our beach, clamming on the bar at every low tide." "I guess we had better tie up yonder," said Olaf, when they had gone a couple of miles up the river. "And then I can put the children in the little boat and pole them in among the reeds." So the Doctor and Olive went ashore, where the sharpie was tied to the end of what had once been a small wharf, while Dodo, Nat, and Rap crouched down in the dingey, obeying Olaf's order to keep very still and not make the boat tip. The little reed-bordered creek that they entered was quite narrow, and soon grew to be only a thread of water, where they could touch the reeds on both sides. They heard many rustling sounds, but for some time could see nothing. Olaf, who was watching, suddenly laid down his pole, and seizing an oar gave the water two or three sharp slaps. Instantly half a dozen strange-looking birds started out, flapping and sprawling, with their legs dangling, one or two seeming to slide across the water, till they all disappeared among the flags again. "Oh! how funny they are!" cried Nat. "They have such foolish-looking faces, little perky tails like a Wren's, and such long, loose feet! Why didn't they fly instead of dodging about so--are their nests in the reeds?" "They do nest here; but now that the season is over, they stay about picking up food from the mud until they shift southward a piece for the winter. These Rails fly well enough when they once get started, and go a long way without stopping. But they are lazy about it in their summer homes, where they only flap up and then dodge down again to hide; so they are easy shooting--too easy to be any sport. It's what I call killing, not hunting." [Illustration: Virginia Rail.]