part
black; bill yellow and greenish, with black on top; bare skin between it
and the eyes blue.

A Citizen of North America.

A member of the guild of Wise Watchers who is wise enough to mind his
own business and do nobody any harm, though he is not inclined to be
sociable with House People. "I think we had best be going toward the
house," said Olaf, glancing at the sky; "there's thunder-heads racing
up." So the children, always ready for something new, started eagerly,
and bewildered Olaf with questions about clouds and weather signs all
the way home.

CHAPTER XXIX

UP THE RIVER

The thunder-clouds thickened until the whole sky was black; the tide
rose in great waves, and the children were glad to be in the house. But
the storm played so many strange pranks that they could not keep away
from the windows, asking a hundred questions about things that cannot be
put in a bird book.

"If the water keeps up on end, as it is doing now," said Olaf, "it will
be a week before I dare take you over to Gull Island; but I was talking
to a man from up the river yesterday, and he says the reed shallows are
full of Rails--maybe you'd like to see them."

"Rails, what are they?" asked Nat. "I thought rails were the steel
things that cars run on, or else some kind of fence bars."

"The Rails that Olaf speaks of are marsh birds," said the Doctor. "Some
are about as big as Robins, and some are bigger still, shaped like
long-legged, long-necked, bob-tailed Hens, with long curved beaks. In
fact, some members of the family are called Marsh Hens from this
resemblance. Olaf often guides gunners through the waterways to find
these birds; he shall take you also, and perhaps you may find some old
Marsh Wrens' nests at the same time."

The next morning was clear and warm, and the children tumbled out in
their flannel bathing-suits to have a dip before breakfast. Rap, by
rolling over and over on the sand, was in the water as soon as Nat; but
they did not venture out far, even though the tide was low, contenting
themselves by splashing about in shallow places.

[Illustration: Turnstone.]

Presently Nat spied something on the stony end of the bar that stretched
out at the right of the beach, and pointed it out to Rap, who said:
"They are some sort of birds: you had better get the glass, for even if
we could go nearer to them, they would be sure to see us and skip." Then
Nat brought the glass and they each took a peep.

"The bo