He turned to the range-rider, and began to explain how the rocks were made, either by deposits under the sea, or by the mud carried down by rivers, or at the bottoms of lakes, or by dust carried in large quantities by the wind, or by ashes from volcanic eruptions. He showed that different kinds of animals lived at various ages, and since they all had to die, the skeleton of one kind would be found in one layer of rock, of another, in a different formation.
“Look here, Dick,” he continued, thinking out some way to make the idea clear, “suppose for a minute that you were a carver, whittling toy animals out of wood. We’ll suppose that the thing you like to carve best is a horse.”
“Happens that I do whittle,” said the cowboy, “an’ you hit the bull’s-eye first time—what I like best to whittle is ponies.”
“Good,” said Perry, feeling that his illustration would carry successfully. “My next ‘supposing’ won’t be as easy.”
“Shoot!”
“Supposing you lived to be a thousand years old.”
“Don’t expect to,” said Round-up Dick; “still, I c’n pipe-dream as good as the next man. All right, I’m goin’ to live a thousand years. I’m to be whittlin’ steady all the time?”
“All the time,” said the boy.
“I’d be neck-deep in shavin’s,” said the rider.
“Fine,” said Perry, “that was just the idea I wanted you to get. Now, we’ll suppose that when you started whittling you had a jack-knife, a good one, of course, sharp and all that sort of thing, but still a jack-knife. And we’ll suppose that the only kind of wood you could get hold of was pine.”