《瓦尔登湖·第十六章·冬天的湖·The Pond in Winter》第6节
As I sounded through the ice I could determine the shape of the bottom with greater accuracy than is possible in surveying harbors which do not freeze over, and I was surprised at its general regularity. In the deepest part there are several acres more level than almost any field which is exposed to the sun wind and plough. In one instance, on a line arbitrarily chosen, the depth did not vary more than one foot in thirty rods; and generally, near the middle, I could calculate the variation for each one hundred feet in any direction beforehand within three or four inches. Some are accustomed to speak of deep and dangerous holes even in quiet sandy ponds like this, but the effect of water under these circumstances is to level all inequalities. The regularity of the bottom and its conformity to the shores and the range of the neighboring hills were so perfect that a distant promontory betrayed itself in the soundings quite across the pond, and its direction could be determined by observing the opposite shore. Cape becomes bar, and plain shoal, and valley and gorge deep water and channel. When I had mapped the pond by the scale of ten rods to an inch, and put down the soundings, more than a hundred in all, I observed this remarkable coincidence. Having noticed that the number indicating the greatest depth was apparently in the centre of the map, I laid a rule on the map lengthwise, and then breadthwise, and found, to my surprise, that the line of greatest length intersected the line of greatest breadth exactly at the point of greatest depth, notwithstanding that the middle is so nearly level, the outline of the pond far from regular, and the extreme length and breadth were got by measuring into the coves; and I said to myself, Who knows but this hint would conduct to the deepest part of the ocean as well as of a pond or puddle? Is not this the rule also for the height of mountains, regarded as the opposite of valleys? We know that a hill is not highest at its narrowest part.
注释摘要
梭罗在这段文字里做了一件非常落实的事：趁着湖面冰封，他用铅垂线透过冰窟窿测量了瓦尔登湖底的地形。冰层给了他一个不冻港所没有的稳固平台，使他的测量结果比通常的水文勘测更为精准。这一态度本身就带有他很典型的特征——不满足于传闻与乡野奇谈，偏要自己拿着绳索和石头去求一个数。他提到的“rod”是一种老式长度单位，一rod等于十六英尺半，三十rod大约是四百九十五英…