Unexplored!

The bedraggled boys allowed Norris to help them out of their heavy, water-soaked clothing, for their hike down the mountainside in the night wind had fairly stiffened their joints. First Long Lester administered a quart apiece of scalding tea, then insisted that, fagged as they were, they bathe their feet. “A camper is as good as his feet,” and Pedro had yet to be located.

It was decided that, as they were all of them worn out, and Pedro, wherever he was, would likely sleep himself when night came, they would wait till dawn to search for him and the Mexicans. While it was a question as to whether they were still in the cave, it seemed best to search there first.

At the moment of the earthquake, Pedro had been crawling through a narrow passageway, bed of some former watercourse, whose walls dripped black in the glow of his dying torch. Then came a crash before him! – A chunk of rock had fallen from the roof into the passageway. When the alarming swaying motion and the thunder of the bowlder’s fall had subsided, and he had relighted the torch, (which had been extinguished), he found his forward progress effectually blocked. Behind were the Mexicans, – Sanchez possibly still plugging the opening into the passageway. He was a prisoner! He was entombed!

At first, utter panic possessed him. In like situation, those of weak, nervous timbre have been known to go insane. Then he got a grip on himself and reasoned that Norris and the rest would not leave him to his fate. They would never give him up till they had searched the cave thoroughly, and had he not left his bandanna at one turn, his handkerchief at another, and the end of a freshly charred torch at a third? Besides, (he smiled grimly), if his own party did not find him, the Mexicans might. Or if they captured the Mexicans, they would wring from them a confession of his near whereabouts. (This time he laughed outright at thought of Sanchez the Stout still dangling his helpless legs when the Ranger found him. The sound echoed and reëchoed weirdly.)

This experience had done much for Pedro’s untried courage. For after all, is it not the unknown that terrifies us rather than the actual calamity to be faced? Another thing that helped the Spanish boy to be reasonably philosophical, – probably the biggest factor, after all, – was Nature’s medicine, his extreme physical fatigue. Thrusting his hat through a narrow crevice so that it would be seen and recognized by any one coming that way, he stretched himself out flat on his back on a bit of smooth, dry rock, thriftily extinguished the remaining bit of torch, and was instantly asleep.

He awoke, he knew not how much later, – but he felt refreshed, – to hear the sound of voices echoing and reëchoing faintly, far down the passageway. Fumbling frantically for a match, he yelled for help with all the power of his trained voice. (And the sound echoed back and forth.) At first Norris and the boys could not tell from which direction it came. Then Long Lester, who was in advance, saw the hat, and it but remained to remove the bowlder.

Now it was that they had use for their ingenuity, for their combined efforts did not suffice to budge the fallen rock. The cavern in which Pedro had become immured was off a lateral passageway leading, – if he had taken the turn to the right instead of the one to the left, – to the very cave mouth by which the rescue party had reëntered; for Long Lester had found, not far from the waterway through which the two boys had come, – but on a higher level, – some scratches on the rocks and a heel print in the scanty soil that told the old mountaineer as plain as words that that was the way Radcliffe had come. Every heel in the party was different, one having Hungarian hob-nails set in a semi-circle, another a solid design in the same nails, a third the larger hobs, a fourth none. He knew the differences in size and the ones that were worn deeper on the inside of the foot. To him a footprint was as good as a signature, and better, for like an Indian, a “hill billy” can often read how fast you were going from a group of two or three foot-prints, how tired you were, and much besides. This knowledge had served them in good stead. He now hurried back to the cave mouth with Ace, found a down log that would serve as a lever, and they pried away the bowlder that kept Pedro a prisoner.

Sign of the Mexicans they could not find, save that Sanchez had been removed from the crevice of the stalactites, (at least he was no longer there), but whether he had had to fast or not, they could not tell. The Mexicans evidently knew the cave and they had been near the southern end of it. Though Long Lester could find no trace of their footprints at either of the exits they knew, there were doubtless others, and it seemed the wisest course now to look for them outside. For the boys were still unwilling to give up the chase.

Reporting back to Radcliffe, they learned, to their amazement, that the pack burros the Mexicans had left near the northern cave mouth had disappeared, but where, they could not tell from any sign left on the charred ground outside.

The Ranger would start a search for them in the DeHaviland, once the fire was under better control. The Forest Service finds its air service as useful in keeping track of law breakers as of fires. It would be an extraordinary thing if the careless camper should escape detection, for the air men can spy them out as easily as anything. But the fire still ate angrily through the timber, and would spread in all directions if left to itself. Fire fighting is sometimes a matter of weeks.

It was a dry summer, and all up and down the Sierras, the Rangers were kept busy fighting the fires that would break out from one cause or another. The Service ’planes were all busy.

The five campers were back at fire-fighting headquarters, – and Norris too, – when Ace had an idea. He and Ted would go in search of the Mexicans in his little Spanish ’plane. Would Radcliffe let them off the fire-fighting? He would, though he could not give official sanction to their plan. It was enough. The two boys were off before he could change his mind, – to Norris’s slight uneasiness and Pedro’s envy. (But Pedro was subject to altitude sickness.)

Sometime, Norris had promised Ted, they would go back into the cave and look for his fossil. But that could wait.

All that afternoon the two boys curveted over the surrounding scenery, – careful to keep their distance from the whirlwind of fire-heated air, for they were flying low. The most minute search failed to reveal the fire setters, but Ace only set his jaw the more determinedly.

They returned to sleep twelve hours at a stretch. Aviation is the best cure yet for insomnia, and neither Ace nor Ted had ever been troubled with that malady. The next day they flew farther, carrying with them an emergency camp kit. They landed about every two hours, rested awhile, and finally went into camp about four in the afternoon, intending to take a look in the night to see if the fugitives would betray themselves by a bon-fire. They camped in a meadow where they had seen something like smoke arising. This proved to be steam from a hot spring, and they thought with longing how fine their chilled bones would feel in a good hot bath. But the spring water came too hot. (If they had had eggs, they could have cooked them in it.)

Then it occurred to them to dig a little trench, line it with stones, and carry the spring water by the folding canvas pailful to fill it. It would quickly cool to the right temperature. The scheme worked wonderfully.

The water had a strong mineral taste, not altogether agreeable, but its effect on aching bones was wonderful. A flint arrowhead buried in the soil they excavated told its tale of Indians, who must have valued the spring and fought for its possession against covetous tribes.

“What makes these hot springs, anyway?” asked Ted. “Have you had that yet in your geology?”

“Yes, but you’ll understand better when Norris tells us the story he’s promised about the formation of the earth. I’m no professor.” And he turned a former laugh on Ted. “Tell you what, Old Top, once we get these fire bugs located for our Uncle Sammy, what say we fly up and have a look at Lassen volcano before I send the ’plane back?”

“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 vertebræ 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 pronouncement 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 mass at the rate of perhaps ten miles a second!–”

“It shore must have het things up some,” said Long Lester.

“It did! Literally melted the rocks. On top of that, this original earth mass, 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 shell in volcanoes, as the heat rose to the surface.”

“Thet sure must have been hell,” 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 amœbas or some simple form of protoplasm. For with the formation of the gases of the earth mass 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 space 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 mass.”

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

“Very likely,” assented 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.

“Either that or volcanic lava.”

“But how did it–”

“Just a minute. Of course land masses have gone down as well as up, but the general trend has been decidedly upward, while the trend of the ocean floor has been downward. At that, the shell of the earth – so to speak – is only about 150 miles thick or a fiftieth of the earth’s present diameter.”

“Then I should think the oceans would be growing deeper,” ventured Pedro.

“Right again. When this earth reaches its old age, – speaking in terms of centuries, – it will likely be all ocean. And there used to be far more land, in proportion, than there is now. There was less ocean water then because of all that is continually pouring through hot springs.

“Of course the land is slowly being washed back into the ocean. And the higher the mountains, the steeper the stream beds, and hence the faster the streams, and the faster they erode the high elevations, till finally all is reduced to sea level again.”

“Then how do the mountains get rebuilt?” Pedro testified his interest.

“The earth has, as I think I said before, shrunk between 200 and 400 miles in diameter, – since the beginning, – ‘when the earth was unformed and void, and darkness was upon the face of the deep.’ It is still shrinking. And this internal movement is felt on the surface in differences that generally amount to only a few hundred feet. I can show you places over there on the East wall of the Sierras where the mountains have been upthrust that way.

“Then, every now and again, the interior activities fairly break the rocky earth shell or lithosphere, and whole mountain ranges are raised. There have been at least eight such minor breaks in the earth crust in North America alone, and each time ranges perhaps a thousand miles long, or more, have been raised near one end of the continent or the other. In addition, there have been major re-adjustments that thrust whole continents higher and ocean beds lower. Geologists find evidence of at least six of these major breaks in the earth crust, – marking the beginnings of the Archeozoic Era, when life originated, the Proterozoic Era, or age of invertebrates, the Paleozoic Era or age of fish dominance, the Mesozoic Era or age of reptile dominance, the Cenozoic Era or age of mammal dominance, and the present Psychozoic Era or age of man.”

“Phew!” whistled Long Lester again. “Don’t tell me this earth used to be all fish.”

“It did, though. We’ll go into that some other time. I’ll just finish about continent building now, and then we’ll turn in. At these times when the lands are at their highest and the oceans are smallest in breadth, (because greatest in depth), the continents are united by land-bridges such as those we have now uniting North and South America.”

“And Alaska and Asia?” suggested Ted.

“Practically, yes. And probably, at one time, South America and Australia. These land-bridges changed the direction of the ocean streams. You know in the age of reptiles there was nothing to divide the Atlantic from the Pacific. Added to that, the high mountain ranges took the moisture out of the winds from the oceans, as the Rockies now do the Pacific trade winds, so that by the time they reach Nevada there is no moisture left in them to form clouds and fall in rain, and we have desert.

“Of course the animals that lived on the earth in its flatter, more temperate stage now have to adapt themselves to life on high, cold elevations, or in dry, hot desert areas, or to migrate via the land-bridges to more favorable climates. Those unable to do this perished.

“For instance, take the age of reptile dominance, (the Mesozoic Era), which was in turn divided into four periods, those of dinosaurs, (the Triassic period, a rock from which I showed you, if you remember), the Jurassic period, which gave rise to flying reptiles, from which our first birds were derived; the Comanchean period, which gave rise to flowering plants and the higher insects, and the Cretaceous period, when our most primitive mammal forms evolved.

“At first the earth was peopled with dinosaurs and flying dragons, and the seas by squid-like mollusks. In those days all the earth was level, swampy, tropic and overgrown with giant tree ferns and a primitive conifer.

“As the high mountain ranges arose and deserts were made, these forms gradually gave way to flowers and hardwood forests, peopled with insects and mammals. Only the most intelligent forms survived, and the struggle itself developed a higher degree of intelligence.”

“What in tarnation were dinosaurs?” asked Long Lester.

“Oh, haven’t you ever seen pictures of them?” laughed Ace. “Picture a giant lizard, perhaps 40 feet long–”

“Here, here,” protested the old man. “I don’t bite.”

“It is perfectly true,” said Norris soberly.

“Honest Injun!” vowed Ace. “One of these fellows was a sort of cross between a crocodile and a kangaroo, what with his long hind legs that he could walk half erect on. There were some as small as eight or ten inches, too, and some so large that you wouldn’t have come to his knee. His big toe was as long as your arm.”

“And how do you know all that?” protested the old prospector feebly.

“By their bones, – fossils. Why, there have been fossil bones of a dinosaur found right in the Connecticut Valley! There was one found a hundred years ago in Oxford, England. We have heaps of fossils of them out West here. In fact, this part of the world used to be their stamping ground, though fossils of them have been found as far away as New Zealand.”

“Did they eat people?” gasped Lester.

“There weren’t any people in those days to eat, but some of them preyed on other animals, and some browsed on the herbage of the swamps. They didn’t have much of any brains, the Triceratops, dinosaurs twice as heavy as elephants, that looked like horned toads, didn’t have two pounds of brains apiece, or so we infer from the size of their skulls. They knew just about enough to eat when they were hungry, and not enough to migrate when things got unlivable for them, and so they perished off the face of the earth.”