crumbling ruin of the old watch-tower.

From the base of this tower, which now threw its shadow forward, bits of
rock kept flying out into the open gulf--skating upon the air until they
lost their momentum, then falling like chips until they rang upon the
ledges at the bottom of the gorge or splashed into the stream. Biltmer
shaded his eyes with his hand. There on the promontory, against the
cream-colored cliff, were two figures nimbly moving in the light, both
slender and agile, entirely absorbed in their game. They looked like two
boys. Both were hatless and both wore white shirts.

Henry forgot his pick-axe and followed the trail before the cliff-houses
toward the tower. Behind the tower, as he well knew, were heaps of
stones, large and small, piled against the face of the cliff. He had
always believed that the Indian watchmen piled them there for
ammunition. Thea and Fred had come upon these missiles and were throwing
them for distance. As Biltmer approached he could hear them laughing,
and he caught Thea's voice, high and excited, with a ring of vexation in
it. Fred was teaching her to throw a heavy stone like a discus. When it
was Fred's turn, he sent a triangular-shaped stone out into the air with
considerable skill. Thea watched it enviously, standing in a
half-defiant posture, her sleeves rolled above her elbows and her face
flushed with heat and excitement. After Fred's third missile had rung
upon the rocks below, she snatched up a stone and stepped impatiently
out on the ledge in front of him. He caught her by the elbows and pulled
her back.

"Not so close, you silly! You'll spin yourself off in a minute."

"You went that close. There's your heel-mark," she retorted.

"Well, I know how. That makes a difference." He drew a mark in the dust
with his toe. "There, that's right. Don't step over that. Pivot yourself
on your spine, and make a half turn. When you've swung your length, let
it go."

Thea settled the flat piece of rock between her wrist and fingers, faced
the cliff wall, stretched her arm in position, whirled round on her left
foot to the full stretch of her body, and let the missile spin out over
the gulf. She hung expectantly in the air, forgetting to draw back her
arm, her eyes following the stone as if it carried her fortunes with it.
Her comrade watched her; there weren't many girls who could show a line
like that from the toe to the thigh, from the shoulder to the tip of the
outstretched han