"Your theory is at least a very ingenious one," observed Locke, and I am reminded by it of another of the natural phenomena,

“你的理论至少是极为巧妙的，”洛克沉吟道，由此，我联想到另外一个自然现象，

of the true explanation of which I have not been able to satisfy myself.

对此我尚且无法得到满意的真实解释，

It is this: what makes the earth freeze harder and deeper under a trodden path than the untrodden earth around it?

即：踩踏道路与未经踩踏道路相比，什么原因造成前者地面比后者地面结冰坚硬厚实？

All that I have asked, say it is because the trodden earth is more compact. But is that reason a sufficient one?

我想问的是，原因在于踩踏后的地面更为密实，不过，这一理由足够充分吗？

"No," said Bunker, but I will tell you what the reason is, for I thought that out long ago.

“不，” 邦克说，不过，我会告诉你其中原因，因为很久前我已弄清这一问题。

You know that, in the freezing months, much of the warmth we get is given out by the earth,

你要知道，在结冰季节里，即使并非持续进行，我们获得的大多暖气由地面不时地往外发散，

from which, at intervals, if not constantly, to some extent, ascend the warm vapors to mingle with and moderate the cold atmosphere above.

在一定程度上，暖空气上升与其上方的冷空气混合，然后减弱。

Now these ascending streams of warm air would be almost wholly obstructed by the compactness of a trodden path,

上升的暖气流几乎被践踏后坚实路面完全阻隔，

and they would naturally divide at some distance below it,

从而在地面下以某种距离自然间隔，

and pass up through the loose earth on each side, leaving the ground along the line of the path,to a great depth beneath it,

再通过周边松软土层向上发散，使得成段路面到地表下相当深度冰冷僵硬，

a cold, dead mass, through which the frost would continue to penetrate,

严霜持续从地层渗透往下，

unchecked by the internal heat, which, in its unobstructed ascent on each side,

但地表下端热量无法遏制，周围上升热量无法拦阻，

would be continually checking or overcoming the frost in its action on the earth around.

运动中地表周围的暖气流将与冷气流持续抗衡甚至最终成功遏制对方。