第2章　地球是圆的，我曾环绕一周

大家有没有离家出走过呢？

很久以前，我比你们都要小的时候，就离家出走过一回。

当时，我希望去看一看世界。

我的妈妈告诉过我，说世界是一个巨大的圆球；因此，假如径直向前走，朝着自己鼻子所指的方向一直走下去的话，那我就会环绕地球一周，然后再回到出发的那个地方。

于是，有天清晨，在没有告诉任何人的情况下，我开始去环绕地球了。

不过，我还没走多远，天就黑了，一个好心的大个子警察，把我送回了家。

待到我长大成人、却还没有成家的时候，我又一次开始出发去周游世界了。这一次，我坐上火车，朝着太阳落下的方向而去。夜幕落下，可没有好心的大个子警察再把我送回家去了。因此，我一直不停地往前，日复一日、周复一周、月复一月地前进。虽说有时是坐火车，有时是坐小船，有时是坐汽车，有时是骑在牲口背上，但我始终都是朝着太阳落下的那一方而去，即始终朝着人们所称的“西方”而去。

我经过了许多辽阔的田野、茂密的森林，经过了许多小型的城镇、大型的城市，我跨过了许多桥梁，绕过了许多山岳，穿越了许多山间的隧道；我到达了一个

on a big ship to another continent—I came to strange lands where people dressed in strange clothes, lived in strange houses, and spoke strange languages；I saw strange animals, trees, and flowers；I crossed another great ocean and at last, after many, many months, always going in the same direction, I came back here to the exact spot from which I had started. So I knew the World was round, for I had been round it—but it was not round and smooth like a tennis ball, but humpety and bumpety, and so huge that it didn't seem like a ball at all.

It took me nearly half a year to go round the World—that seems like a long time, but then it was a long way—over twenty-five times a thousand miles. But others have been around the World in much faster time.The airship Graf Zeppelin flew around the World in three weeks.Two flyers took less than nine days to circle the globe in their airplane and return to their starting point, New York.An American Air Force plane flew around the World without stopping in less than four days.

If a man could start out when the sun rose in the morning and keep up with it all day long, go over the side of the World when the sun set, and keep up with it on the other side of the World, he would be back again where he started the next morning. He then would have gone round the World in one day.But to do that he would have to travel over 1，000 miles an

广袤的大洋，坐上一艘巨大的轮船，横跨这个大洋，到达了另一个大洲，我来到了许多陌生的国度，那里的人都穿着奇怪的服装，居住在奇怪的房子里，并且说着奇怪的语言，我看到了许多陌生的动物、树木和花草。我跨过另一个大洋，并且在始终朝着同一个方向旅行了许多许多个月之后，最终又回到了我出发的这个地方。因此，我知道地球是圆的，因为我已经环绕了它一周。不过，地球并不是像一个网球那样浑圆、滑溜的，而是坑坑洼洼，像个鸡蛋，并且极其巨大，因此看上去根本就不像是一个球呢。

我花了差不多半年的时间，才环绕了地球一周，这似乎是一段很久的时间，但在那时，这也是一段很长的距离，达到了两万五千多英里呢。不过，其他一些人环绕地球所花的时间，却要比我短得多。飞艇“格拉夫·齐柏林”号只用了三个星期，便绕着地球飞行了一圈。有两位飞行员，曾经驾驶着各自的飞机，不到九天便环绕了地球一周，然后回到了他们的出发地纽约。美国空军的一架战斗机要是连续飞行、中途不停的话，只需不到四天的时间，便可绕地球一周呢。

假如一个人能够在清晨太阳升起的时候出发，并且一整天都跟着太阳跑，到太阳落山的时候便走完了地球的一面，并且再跟着太阳走完地球另一面的话，那么他第二天早上便会回到自己的出发地。这样，他就是在一天之内环绕了地球一周。不过，要做到这一点，在一天一夜的二十四个小时内，他每个小时都必须走上一千多英里，才能赶上太阳的步伐。

hour to keep up with the sun for each of the twenty-four hours in a day and night.

All around the outside of the World—as you probably know—is an ocean of air that covers everything on the World as the ocean of water covers everything in the sea. What you probably don't know is that this ocean of air is wrapped only round the World—it does not fill the sky.Men and animals live in this ocean of air as fish live in the ocean of water, and if a huge giant picked you out of the air you would die just as quickly as a fish does when taken out of the sea.The air is thick near the ground but gets thin and thinner the higher up you go off the ground.That's why airplanes can go up but a few miles high—there is not enough air to hold up the plane, for the plane must have air to rest on and for its propeller to push against, just as a boat in the water must have water to rest on and water for its propeller to push against.Or if it's a jet plane, it must have air to feed its jet motors.An airplane could not rise beyond the ocean of air and sail off into the sky where there is no air any more than a steamship on the sea could rise out of the water and sail off up into the air.

There is only one thing that men can send up high enough to travel above the ocean of air. That is a rocket, which doesn't depend on air for its motor or to hold it up.Someday rocket ships will probably carry men on trips to the Moon or even to the planet Mars.How would you like to go exploring in a rocket ship beyond the World's atmosphere out through empty, airless space?How would you like to be the first Man in the Moon?You wouldn't find any living thing on the Moon, for the Moon is a dead, lifeless ball without any air on it at all.But if your rocket got to Mars you would almost certainly find some

你们很可能都知道，环绕在地球外部的，就是大气层。就像海水淹没了海中的一切那样，大气也淹没了地球上的一切。而你们很可能不知道的，就是这个大气层只是环绕在地球的外部，却没有填满整个天空。人类和动物都生活在这个大气层里，就像鱼儿生活在海水当中一样，要是一个巨人把你们拎起来扔出大气层，那你们很快就会死去，就像离开了海水的鱼儿一样。越是靠近地面的地方，空气密度越大，而离地面越高，空气就会变得越来越稀薄。飞机之所以只能飞到几英里高的地方，原因就在这里：高空中没有足够多的空气来支撑飞机，因为飞机必须有空气才能浮在空中，飞机的螺旋桨才能产生推力，这个道理，跟水中的船只必须有水才能浮在水上、船只的螺旋桨才能产生推力是一样的。就算是一架喷气式飞机，也必须有空气吸入其喷气式发动机才行。飞机没法上升到大气层以上的高度，无法进入太空，就像大海上的一艘汽轮没法浮到水面以上，没法在空中航行一样。

人类只能发射一种飞行高度能够达到大气层以上的设备。那就是火箭，因为它不依靠空气来驱动它的发动机，也不依靠空气来支撑其自身的重量。有朝一日，宇宙飞船很可能会把人类运送到月球、甚至是火星上去旅行呢。你们喜不喜欢乘坐宇宙飞船，到地球的大气层以外，去探索那空无一物、没有空气的宇宙空间呢？你们希不希望自己是第一个到达月球上的人类呢？你们在月亮上可不会找到任何生物，因为月亮是一个死气沉沉、没有生命的星球，上面根本就没有空气。不过，如果你们乘坐火箭来到了火星上，那就极有可能发现某些活体植物，甚至是某些活体动物。但这也是没准的事情，谁知道呢？

living plants—and perhaps, who knows?—even some living animals.

Some mountains are so high that their tops almost stick out of the ocean of air；at least, there is so little air covering their tops that people can't go all the way to the top unless they take along canned air to breathe.

You can't see air—you may think you can, but what you see is smoke or clouds, not air. When air is moving, we call it wind.Then you can feel it when it blows your hat off, you can hear it when it bangs the shutters and whistles round the house；but no one has ever seen air itself.

The World wasn't always as it is now. It was once a ball of fire—a huge burning ball.That was millions of years ago, and of course long before there were any people or animals or plants on the World.But the fiery ball got cooler and cooler until it was no longer burning but a hot ball of rock.There were then no oceans, no water on the World, for water won't stay on anything very hot—it won't stay on a hot stove—it turns to steam when there is fire under it；so there were only clouds of steam, an ocean of steam, around the World.But the World kept getting cooler and cooler until at last the steam turned to water and fell on the World—rain, rain, rain, until there perhaps was one big ocean covering the whole World.

But the World still kept on cooling and cooling, and as it cooled it shrank and shriveled and wrinkled and crinkled and puckered like the outside of a prune. You know a prune was once smooth and round when it was a plum.These little wrinkles and crinkles rose up out of the ocean and were the continents and mountains, so you see how big the wrinkles and

地球上有些高高耸立的山脉，山顶几乎伸到了大气层之上，起码来说，这些山脉顶上的空气非常稀薄，因此人类除非携带着呼吸用的罐装空气，否则便没法登上这些山顶呢。

大家是看不到空气的，虽说你们可能以为自己看得见，但其实你们见到的都是烟雾或者云朵，而不是空气。空气流动的时候，我们便称之为风。这样，当风吹落你们的帽子时，你们就可以感觉到空气，当风啪啪地敲击着百叶窗、在你们家房子周围呼啸而过的时候，你们也能听得到空气的声音，不过，迄今为止，还没有人见到过空气本身呢。

以前，地球并非始终都像如今这个样子。它曾经是一个大火球，一个巨大的、熊熊燃烧着的火球，那还是数百万年前的事情了。当然，也是在这很久以后，地球上才出现了人类、动物或者植物。不过，熊熊燃烧着的地球后来变得越来越冷，最终不再燃烧，成了一个由岩石组成的炽热球体。当时，地球上还没有海洋，没有水，因为任何炽热之物上都是存不住水的，下面有火加热时，水就会变成蒸汽，因此，当时地球上只有一团团的蒸汽，形成了环绕地球的一个蒸汽层。但是，地球继续变得越来越凉，最终这些蒸汽冷凝成水，落到了地球上，形成了雨，雨不停地、不停地、不停地下着，直到整个地球上可能都被一个巨大的海洋所淹没了。

但是，地球还在继续变得越来越凉爽，而在变冷的过程中，地球又开始变小、收缩、起皱、缩褶和皱起，就像梅干的外皮一样。你们都知道，梅干在新鲜的时候，原本都是又光滑又圆润的。这些小的褶子和皱纹升到了海洋之上，变成了大陆

crinkles really are. The earth is still wrinkling a bit even now, and when it does so it shivers and shakes and we say there has been an earthquake.But the earthquakes nowadays are as nothing to what may have been the tremendous shudder when the continents rose out of the first single ocean.The thunderous roar of that quake may have reached the stars with a stupendous and appalling boom of a bursting, cracking, rending, groaning World, as if the last day had come.Don't you know what stupendous and appalling boom means?Why, it means“stupendous and appalling boom.”But that's all guess—for the continents may have risen out of the sea as softly, slowly, silently as a blade of grass grows out of the ground.No one knows.We only know the continents did rise out of the water—we can find seashells on the tops of high mountains, and we know they could only have been made under the water when the mountain was under the water.

和山脉，因此，你们完全可以想见，这些褶子和皱纹实际上有多巨大。即便是到了如今，地球也仍在轻微地收缩着。当地球收缩的时候，就会地动山摇，而我们则称这种现象是发生了地震。不过，如今的地震与当初陆地从一整片海洋中耸立而出的时候那种山崩地裂式的震动相比，根本就算不上什么了。这种震动所带来的巨大声音，伴随着爆炸、裂开、分裂、咆哮的地球发出巨大而可怕的轰鸣之声，可能响彻了宇宙，直抵各大恒星，仿佛是世界末日降临了一般呢。你们知道“巨大而可怕的轰鸣之声”是什么意思吗？嗨，它指的就是“巨大而可怕的轰鸣之声”。不过，这一切全都属于我们的猜测，因为各个大陆也有可能是轻柔、缓慢而无声地升出海面的，就像地上生长出的一片草叶那样。没人知道实际情况究竟如何。我们只知道各个大陆的确是从水中耸立出来的，因为在一些高山之巅，我们如今还能找到海贝，而我们也知道，这些海贝是在水下生成的，因此只可能是在山脉还位于海底的时候留下来的。