"Go right ahead, Zeph," insisted Ralph encouragingly, "we're interested."
"Well, up among those big stone terraces is the whistling race. They are able to converse with one another at a distance of three miles."
"That's pretty strong," observed Fred. "But make it three miles."
"A Silvando will signal a friend he knows to be in a certain distant locality. He does it by setting his fore fingers together at a right angle in his mouth, just as you'll see these two Canaries do in a minute or two. An arrow of piercing sounds shoots across the ravine."
"Arrow is good—shoots is good!" whispered Fred, nudging Ralph.
"There is a moment's pause—" continued Zeph.
"Oh, he's read all this in some book!" declared Fred.
"Then there comes a thin almost uncanny whistle from far away. Conversation begins, and as the sounds rise and fall, are shrill or drawn, so they are echoed. Then comes the ghostly reply, and then question and answer follows. They talk—all right. Travelers say so, and a lot of scientific fellows are now on the track of this strange tribe to investigate them before civilization makes of their talk a dead language.
