Lesson 50 Only A Stone
第50课 只是一块石头
What is the oldest thing you have seen? One boy thinks it is a church, for he has seen a date on one which tells that it was built hundreds of years ago.
小朋友，你见过的最古老的东西是什么？有个男孩子觉得是教堂，因为他见过一所教堂（的石头上）刻着一个日期，说这所教堂是好几百年以前建造的。
A girl thinks that an oak-tree which she has seen is older still, for her grandfather says he has read that it was growing a thousand years ago.
有个女孩觉得，她见过的一棵橡树更古老，因为她爷爷说，他在书上看到过，这棵橡树在一千年前就已经有了。
But what is that hard lump which Tommy has in his pocket? It is a stone which he picked up, because it had a curious look.
不过，汤米口袋里的那个硬块儿是什么东西呢？那是一块他捡来的石头，因为他觉得样子很奇怪。
Well, it does not matter much about the curious look, but any common stone you find is almost certain to be the oldest thing you will ever see. The age of most stones goes back many thousands of years.
奇怪的样子倒没有什么关系，但是，你找到的任何平常的石头，几乎都肯定是你能见到的最古老的东西。大多数石头的年纪都有成千上万岁了。
The stone which Tommy has found is called sandstone. It is made of little round grains of sand. Thousands and thousands of years ago these little grains of sand were lying loose on some sea-beach. Since then they have been pressed together so hard and for so long a time that they now form a sandstone rock.
汤米找到的这种石头，名叫“砂岩”，是小小的圆形沙粒构成的。千万年前，这些沙子是散布在一些海岸上的，但是后来，这些沙子用极大的力量挤在一起，挤了很久，最后就形成了砂岩。
But these grains of sand were themselves only broken bits of a still older rock. They must be many thousands of years older than the stone which has been formed out of them.
但是，这些沙粒，本身又是更古老的石头破碎形成的。这种石头，比沙粒形成的砂岩，还要古老成千上万年呢！
If we break up a great many lumps of sandstone, we shall be almost sure to find in some of them the shells of creatures that lived on the old sea-beach.
如果我们将很多块砂岩弄碎，几乎肯定会在一些砂岩里面，找到很久以前在海滩上生活的动物的甲壳。