It was the last week of the children's stay at the shore before everything combined to make possible the sail to Gull Island. They had spent three glorious weeks, and were as ruddy brown as any of the little Indians who had once gathered wampum shells from the same beach in the long ago. They were wiser also in many ways, for they had found out many things for themselves—which is the very best sort of wisdom. Now even Dodo could tell by the footprints on the sand whether a three-toed Plover or a four-toed Sandpiper had been pattering there.
When the right day came, without a sign of ugly squalls or of an equally unfortunate calm, Olaf borrowed a largo cat-boat, and after stowing away the lunch hamper, that was always a 'must be' for an all-day trip, the boat almost flew out of the little bay and up the sound before the breeze that came with the morning tide.
"There are some more of your white Crows, Nat," said the Doctor, as they headed straight out after getting on the right tack. "The island where we are going is one of their famous nesting places."
"Their wings are very different from Crows' wings," said Rap, as he watched them overhead, now winnowing the air with steady wing-beats, or circling on motionless pinions—now poising in one spot for a minute by merely flapping the wings, and then dropping gracefully to float on the water. "Gulls' wings bend out more at the tip and are smooth-edged; Crows' look flatter and are saw-edged."
"Are there any other birds besides Gulls that nest on the island, Uncle Roy?" asked Nat.
"Yes, the Terns or Sea Swallows that you have seen about the reef nest there also; and this island, as well as the mainland near by, is a favorite stopping-place for all the shore and water birds in their journeys,—from Sandpipers to great flocks of Sea Ducks."
"I should think it would be a long swim for Ducks," said Nat; "it is as much as fifteen miles from shore."
"They don't swim—they fly there," said Olaf.