ings," said Rap. "Ah
yes! now I remember about him--we can always tell him from a real Hawk."

"How does he make that queer noise?" asked Nat. "It sounds like when I
hit the telegraph wires with stones, or blow in the bunghole of a
barrel."

[Illustration: Nighthawk.]

"Watch him when he drops," said the Doctor; "do you not see that he
does so with open wings? The air rushes between the long wing-quills and
makes the vibrating noise. Now he is up and away again, but you see he
keeps circling in the sky."

"Does he build in chimneys?" asked Dodo.

"The Nighthawk does not build any nest; the eggs are laid on bare ground
or rock in an open field--occasionally on a house-top. Strange as this
seems, the parent birds are so near the color of earth and rock that it
is very difficult to find them when they are sitting, the young when
hatched are equally invisible, and the eggs themselves look like two
little stones--for there are never more than two. I will show you a
Nighthawk in my cabinet, and you will see for yourselves how nicely the
colors match ground and rocks."

"He looks like a pretty big bird," said Dodo. "How long is he? Is there
only one in his family?"

"He has a brother called the Whip-poor-will, that we should meet very
soon."

The Nighthawk

Length ten inches.

Mottled black and rusty above. Barred on the under parts with black and
white or buff. A white collar on the throat, a white spot going entirely
through the wing, and a white band across the tail.

A Summer Citizen of eastern North America, from the Gulf of Mexico to
Canada, travelling far south for the winter.

A shy neighbor but a valuable Citizen, belonging to the Ground Gleaners
as well as Sky Sweepers.

THE WHIP-POOR-WILL

"This mysterious bird is also a dweller in lonely places, feeding at
night in the woods, having no nest, and laying the eggs in a hollow in
the ground or on a stump or log. He is so nearly of the color of wood,
earth, and rock, that you may pass near him a hundred times and never
see him. Then too, when he perches in the day-time, he does not sit
across a branch like other birds, but lengthwise, so that House People
and cats cannot see him from below or cannibal birds from above. He is
an insect-eater and so goes southward before hard frosts."

"Does this bird make any noise, and why is he called the
Whip-poor-will?" asked Nat; "that is such a funny name."

Rap was about to answer when the Doctor signed t