a model airship," the boy confessed, "but I
didn't find time. I've been lugging 'em around this last week. Now
they'll come in handy."

In a short time each cowboy had made himself a slingshot, of the style
you boys have, doubtless, often constructed. With strong rubber bands
they send a stone with great force.

The slingshots were no sooner made, and a supply of ammunition secured
from the edge of the creek, than an unusual movement was observed among
the sheep herders. Some of them separated from the main body, and
began driving a flock of the lambs, rams and ewes toward the creek.

"Ready for the first skirmish!" cried Old Billee.

"Let her come!" sang out Yellin' Kid.

Nearer to the edge of Spur Creek approached the sheep herders. The
animals bleated and tried to turn back, but the dogs barked at them and
snapping whips whirled viciously over their backs. Then, too, they
were urged on with horses at their heels.

"They're coming right over," said Dick to his brother and cousin, the
three boy ranchers being close together.

"And not one of 'em has a gun out," added Bud. "I reckon they are
making this a sort of test so they can claim we fired on 'em first if
it comes up in a law court. Well, we aren't exactly _firing_ at 'em,"
he chuckled. "We're just _stoning_ 'em."

"And we'd better begin to stone!" cried Nort.

He drew back the strong rubber bands of his sling. In the leather
piece was a round pebble. Nort took aim at one of the approaching
Mexicans.

The skirmishing was about to begin.

CHAPTER XIX

OPEN WARFARE

"Zip!" a stone from Nort's sling cut the air with a vicious ping, and
not only that, but it caught one of the Greasers on the side of his
head. He uttered a cry, dropped his reins and clapped a hand to the
smarting place.

Another instant and he had lost control of his horse, which first swam
down stream and then turned to go back to the shore he had left. One
reason for this was that Nort had let fly a stone that took the horse
on the flank. And Nort was careful not to shoot as hard at the horse
as he had at the rider. In fact the horse was not hurt at all--merely
frightened, for the stone was like a fly-bite.

But it was enough.

Meanwhile the other defenders of Spur Creek had been using their slings
to advantage, first stinging the Greaser riders with vicious stones and
then, more lightly, tapping the horses to demoralize them rather than
to hurt them.

This