Unexplored! Part 15

"Bully! I'd like to fly over a glacier, too, and see what it looks like.

Can you go that high?"

"I--guess so. Never tried it! We will, though!"

"Gee! Wouldn't this be a great way to teach geography--from an aeroplane!"

"Sure would!--Great way to go camping, too."

"'S right, only--it would be if there was just the two of us," sighed Ted ungrammatically. "Could you carry enough grub?"

"We could get fresh supplies every few days, from some ranch."

The next day they went back for the rest of the party and showed them Ted's fossil, entering the cave the way Radcliffe had left it. Norris had spent one summer with fossil hunters in the dry gullies of the Southern end of California, he told them, where through scorching days and thirsty nights they had searched for any bit of bone that might lie amid the shale or imbedded in strata the edges of which might be seen on the face of a sun-baked bluff. The summer before, a group of geology men from a rival University had actually camped within a hundred yards of what was later discovered to be a deposit of rare fossils. It was therefore with heightened satisfaction that their reconnaissance had resulted in the discovery and excavation, bone by bone, of the complete skeleton of several most interesting prehistoric monsters that had lain all these ages embedded in the shale.

One bone four feet long, he told them, and weighing several hundred pounds, had been found in fragments in the shale, but it had been fitted together again, done up in plaster bandages and braced with splints, quite as a surgeon treats a broken leg. Another, found embedded in solid rock, had to be shipped in the rock, each piece being numbered as it was removed from the cliff as an aid to fitting it together again. Then with hammer and chisel the delicate feat of cutting away the rock and leaving the bone exposed was slowly and painstakingly accomplished. Thus have the bones buried before ever man trod the earth been made to tell their story. Often it takes more than a single specimen to reconstruct for the scientist the whole of the creature, but relics of fully thirty Triceratops have been discovered in different parts of the world, and where one skull has a broken nose, another shows it intact, and so on through its entire anatomy.

Its habits may in part be reasoned out, as for instance, if its hind legs are disproportionately long, it likely walked erect at least sometimes.

"That, as it happens, was not the case with Triceratops," he added.

"There was only a slight difference between his fore and hind legs.

Triceratops had teeth made for browsing, not for rending flesh; his single claw, round and blunt, does not indicate any pugnacious tendency on his part, and the solidity of his bones are found to-day in either a very sluggish animal or a partially aquatic one. The shape and rapid taper of the tail vertebrae indicates a rather short tail, round rather than flat,--ill adapted for swimming,--and so following through the list, till we have a Triceratops elephantine in general build, though more like a rhinoceros in face with a horn over his nose and two over his eyes, a horn-supported neck ruff, and a generally sluggish mode of life.

"In the coal fields complete imprints of Ichthyosauria have been found, doubtless due to the carbonization of the animal matter. And impressions have been left in stone of the very feathers worn by some of the now fossilized creatures."

It was by comparison of fossil remains that the well known evolution of the horse from a little fellow the size of a fox was learned. Ted often thought of that three-toed Miocene horse, and the giant monsters of his time,--of the upthrust of the Rocky Mountains, cutting off the moist sea breeze from the marshy country to the Eastward and making desert of it.

This made life too hard for the heavy, slow-witted creatures, and they failed to survive the change. But the nimble footed little horse trotted long distances with ease, to find food and water.

Norris convulsed them by describing the creature on which he declared the aeroplane was modeled,--the pteranodon, that giant lizard, largest of flying creatures even in Mesozoic age, whose bat-like wings reached 20 feet from tip to tip,--as the fossil skeletons plainly prove.

This interesting specimen was a link in the chain between the birds of to-day and their ancestral archeopteryx, no larger than a crow whose front legs metamorphosed to short wings, whose skeletons have been found perfectly preserved in the limestone.

Ted was frantic for fear they would not find the place again, then could hardly wait to hear the Geological Survey man's p.r.o.nouncement on his find. Norris chipped and chipped, with knife and hammer, till he had uncovered the impress of a great, membranous wing.

It was a fossil dinosaur,--a pterodactyl!

Ted's college education was secure!

CHAPTER X

HOW THE EARTH WAS MADE

Ted's fossil would have to wait to be exhumed. In fact, Norris told him, he could sell it as it stood, and let the purchaser do the work. Then it occurred to him to wonder if Ted would not have first to take up a claim,--for it was Government land. Anyway, he would see to it that the boy was rewarded for his find.

The fire now being extinguished, Radcliffe had flown to other battle lines, first taking Rosa--as she insisted--back to her fire outlook. The plan was for the two boys to keep on hunting for the Mexicans, (as the harried Ranger now counted on their doing), joining the rest of the camping party every night, at points they would agree upon. But first, Ace had made a flight to Fresno for supplies and to start his pilot home by train. He then carried them one at a time to where the burros had been left,--and where the lazy rascals still browsed on the rich mountain meadows.

For a day or two, all the boys could talk, think or dream about was the adventures they had just been through. But at last they had relieved their minds to some extent, and one evening around the fire, Norris gave them his long promised explanation of some of the natural wonders they had seen.

"I have already told you," began Norris, "how the earth probably originated. That much the astronomer has given us. And before the geologist can begin to interpret the evolution of our earth, he has to know what scientists have established in the fields of chemistry, mechanics and geodesy,--the study of the curvature and elevation of the earth's surface. He then proceeds to theorize, hand in hand with the paleontologist, or student of ancient life. The newest theory is in line with what I learned in 1917 at Yale."

"It's all theory, then?" asked Ted.

"Just as all sciences are, to some extent. Did I tell you that when our planetary system was disrupted from the sun, it was less than a hundredth part of the parent body? And our earth is a good deal less than a millionth of the size of our sun, and our sun is among the smaller of the stars of the firmament."

"Phew!" whistled Long Lester, round eyed, while Ted and Pedro sat motionless.

"Picture the earth and moon, revolving about the sun, gathering by force of their own gravity-pull the tiny planetesimals nearest them, these bodies hurling themselves into the earth ma.s.s at the rate of perhaps ten miles a second!----"

"It sh.o.r.e must have het things up some," said Long Lester.

"It did! Literally melted the rocks. On top of that, this original earth ma.s.s, composed of molten rock and gases and water vapor, was condensing.

Probably by the time it had engulfed all the stray planetesimals it could, it was anywhere from 200 to 400 times as large as it is now. It has been shrinking ever since."

"Is it still shrinking?" gasped the old prospector.

"Sure thing! But not so fast that you will ever know the difference in _your_ lifetime. It only shrinks at times; then the earth's surface wrinkles into mountain ranges."

"How many times has that been, sixteen?" suggested Ace.

"We'll come to that. As I was going to say, while the earth was so hot, it kept boiling, as it were, inside, and the molten matter kept breaking through the cold outer sh.e.l.l in volcanoes, as the heat rose to the surface."

"Thet sure must have been h.e.l.l," laughed the old man.

"As the cold crust was churned into the hot interior, of course it melted and expanded, and that caused more volcanoes, and so on in a vicious circle, till finally, by the end of the Formative Era, so called, the rock that contained more heavy minerals sank to the lower levels, while the lighter ones rose as granite."

"Gee!" said Ted, "I'd have called granite heavy."

"Not so heavy as the specimens of basic rock we'll find. Well, in this Formative Era our atmosphere, and the hydrosphere or oceanic areas were being formed, along with the granite continents. But while we are on the subject, I hope you boys will some day see The Valley of Ten Thousand Smokes, in Alaska, where the earth is still boiling so close to the surface that you have to watch your step or you'll break through into----"

"The Hot Place?" laughed Pedro.

"Literally, yes."

"Oh, tell us about that!"

"Some time!--The interior of the earth is still hot, but the rock crust allows very little of it to rise to the surface. After the Formative Era came the Archeozoic Era, when life began in the form of amoebas or some simple form of protoplasm. For with the formation of the gases of the earth ma.s.s into an envelope of air, to moderate the sun's warmth by day and retain some of it by night,--life became possible."

"But where did those first creatures come from?" Ted could not restrain himself from asking.

"According to one theory, the first germs of life flew here from some other planet, and not necessarily one of those revolving around our own sun, for s.p.a.ce is full of suns and planetary systems. But that theory can neither be proved nor disproved. When I was a student, Osborn's theory was the latest. That was in 1916. Without going into it too deeply, it had to do with the electric energy of the chemical elements that compose protoplasm, and these always had been latent in the earth ma.s.s."

"Then they must have been latent in the sun, too," marveled Ted. "And in other suns and their planets too."

"Very likely," a.s.sented the Geological Survey man. "Now of course the ocean waters collected in the depressed areas over the heavier rock bottoms, the basalt. You remember just after we lost the burro we were on a basalt formation----"

"Then that was formerly a part of the ocean floor?" asked Ted.