I noticed then what I should have seen before—two little knobs that could move the map. I started to move them and heard a sharp clicking, and the pace of the ship began decreasing. A moment and it had steadied at a considerably lower speed, the machine swinging to a new course. I tried to right it, but to my amazement the controls did not affect it.
It was the map, you see. It would either follow the course, or the course would follow it. I had moved it and the machine had taken over control of its own accord.
There was a little button I could have pushed—but I didn't know. I couldn't control the ship until it finally came to rest and lowered itself to a stop six inches from the ground in the center of what must have been the ruins of a great city. Sacramento, probably.
I understood now, so I adjusted the map for San Frisco, and the ship went on at once. It steered itself around a mass of broken stone, turned back to its course, and headed on, a bullet-shaped, self-controlled dart.
It didn't descend when it reached San Frisco. It simply hung in the air and sounded a soft musical hum. Twice. Then it waited. I waited, too, and looked down.
There were people here. I saw the humans of that age for the first time. They were little men—bewildered —dwarfed, with heads disproportionately large. But not extremely so.
Their eyes impressed me most. They were huge, and when they looked at me there was a power in them that seemed sleeping, but too deeply to be roused.
I took the manual controls then and landed. And no sooner had I got out, than the ship rose automatically and started off by itself. They had automatic parking devices.
The ship had gone to a public hangar, the nearest, where it would be automatically serviced and cared for. There was a little call set I should have taken with me when I got out. Then I could have pressed a button and called it to me—wherever I was in that city.
The people about me began talking—singing almost—among themselves. Others were coming up leisurely. Men and women—but there seemed no old and few young.
What few young there were, were treated almost with respect, carefully taken care of lest a careless footstep on their toes or a careless step knock them down.
There was reason, you see. They lived a tremendous time. Some lived as long as three thousand years. Then—they simply died. They didn't grow old, and it never had been learned why people died as they did. The heart stopped, the brain ceased thought—and they died. But the young children, children not yet mature, were treated with the utmost care. But one child was born in the course of a month in that city of one hundred thousand people. The human race was growing sterile.
And I have told you that they were lonely? Their loneliness was beyond hope.
For, you see, as man strode toward maturity, he destroyed all forms of life that menaced him. Disease. Insects. Then the last of the insects, and finally the last of the man-eating animals.
The balance of nature was destroyed then, so they had to go on. It was like the machines. They started them—and now they can't stop. They started destroying life—
and now it wouldn't stop. So they had to destroy weeds of all sorts, then many formerly harmless plants. Then the herbivora, too, the deer and the antelope and the rabbit and the horse. They were a menace, they attacked man's machine-tended crops.
Man was still eating natural foods.
You can understand. The thing was beyond their control. In the end they killed off the denizens of the sea, also, in self-defense. Without the many creatures that had kept them in check, they were swarming beyond bounds. And the time had come when synthetic foods replaced natural. The air was purified of all life about two and a half million years after our day, all microscopic life.
That meant that the water, too, must be purified. It was—and then came the end of life in the ocean. There were minute organisms that lived on bacterial forms, and tiny fish that lived on the minute organisms, and small fish that lived on the tiny fish, and big fish that lived on the small fish—and the beginning of the chain was gone. The sea was devoid of life in a generation. That meant about one thousand and five hundred years to them. Even the sea plants had gone.
And on all Earth there was only man and the organisms he had protected —the plants he wanted for decoration, and certain ultra-hygienic pets, as long-lived as their masters. Dogs. They must have been remarkable animals. Man was reaching his maturity then, and his animal friend, the friend that had followed him through a thousand millenniums to your day and mine, and another four thousand millenniums to the day of man's early maturity, had grown in intelligence. In an ancient museum—
a wonderful place, for they had, perfectly preserved, the body of a great leader of mankind who had died five and a half million years before I saw him—in that museum, deserted then, I saw one of those canines. His skull was nearly as large as mine. They had simple ground machines that dogs could be trained to drive, and they held races in which the dogs drove those machines.
Then man reached his full maturity. It extended over a period of a full million years. So tremendously did he stride ahead, the dog ceased to be a companion. Less and less were they wanted. When the million years had passed, and man's decline began, the dog was gone. It had died out.
And now this last dwindling group of men still in the system had no other life form to make its successor. Always before when one civilization toppled, on its ashes rose a new one. Now there was but one civilization, and all other races, even other species, were gone save in the plants. And man was too far along in his old age to bring intelligence and mobility from the plants. Perhaps he could have in his prime.
Other worlds were flooded with man during that million years—the million years.
Every planet and every moon of the system had its quota of men. Now only the planets had their populations, the moons had been deserted. Pluto had been left before I landed, and men were corning from Neptune, moving in toward the Sun, and the home planet, while I was there. Strangely quiet men, viewing, most of them, for the first time, the planet that had given their race life.
But as I stepped from that ship and watched it rise away from me, I saw why the race of man was dying. I looked back at the faces of those men, and on them I read the answer. There was one single quality gone from the still-great minds—minds far greater than yours or mine. I had to have the help of one of them in solving some of my problems. In space, you know, there are twenty coordinates, ten of which are zero, six of which have fixed values, and the four others represent our changing, familiar dimensions in space-time. That means that integrations must proceed in not double, or triple, or quadruple—but ten integrations.
It would have taken me too long. I would never have solved all the problems I must work out, I could not use their mathematics machines; and mine, of course, were seven million years in the past. But one of those men was interested and helped me.
He did quadruple and quintuple integration, even quadruple integration between varying exponential limits—in his head.
When I asked him to. For the one thing that had made man great had left him. As I looked in their faces and eyes on landing I knew it. They looked at me, interested at this rather unusual-looking stranger—and went on. They had come to see the arrival of a ship. A rare event, you see. But they were merely welcoming me in a friendly fashion. They were not curious! Man had lost the instinct of curiosity.
Oh, not entirely! They wondered at the machines, they wondered at the stars. But they did nothing about it. It was not wholly lost to them yet, but nearly. It was dying.
In the six short months I stayed with them, I learned more than they had learned in the two or even three thousand years they had lived among the machines.
Can you appreciate the crushing hopelessness it brought to me? I, who love science, who see in it, or have seen in it, the salvation, the raising of mankind—to see those wondrous machines, of man's triumphant maturity, forgotten and misunderstood. The wondrous, perfect machines that tended, protected, and cared for those gentle, kindly people who had—forgotten.
They were lost among it. The city was a magnificent ruin to them, a thing that rose stupendous about them. Something not understood, a thing that was of the nature of the world. It was. It had not been made; it simply was. Just as the mountains and the deserts and the waters of the seas.
Do you understand—can you see that the time since those machines were new was longer than the time from our day to the birth of the race? Do we know the legends of our first ancestors? Do we remember their lore of forest and cave? The secret of chipping a flint till it had a sharp-cutting edge? The secret of trailing and killing a
