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while the 〃fifty…six〃 was resting by the way； they were paying out
the rope in the vain attempt to fathom their truly immeasurable
capacity for marvellousness。 But I can assure my readers that
Walden has a reasonably tight bottom at a not unreasonable； though
at an unusual； depth。 I fathomed it easily with a cod…line and a
stone weighing about a pound and a half； and could tell accurately
when the stone left the bottom； by having to pull so much harder
before the water got underneath to help me。 The greatest depth was
exactly one hundred and two feet； to which may be added the five
feet which it has risen since； making one hundred and seven。 This
is a remarkable depth for so small an area； yet not an inch of it
can be spared by the imagination。 What if all ponds were shallow？
Would it not react on the minds of men？ I am thankful that this
pond was made deep and pure for a symbol。 While men believe in the
infinite some ponds will be thought to be bottomless。
A factory…owner； hearing what depth I had found； thought that it
could not be true； for； judging from his acquaintance with dams；
sand would not lie at so steep an angle。 But the deepest ponds are
not so deep in proportion to their area as most suppose； and； if
drained； would not leave very remarkable valleys。 They are not like
cups between the hills； for this one； which is so unusually deep for
its area； appears in a vertical section through its centre not
deeper than a shallow plate。 Most ponds； emptied； would leave a
meadow no more hollow than we frequently see。 William Gilpin； who
is so admirable in all that relates to landscapes； and usually so
correct； standing at the head of Loch Fyne； in Scotland； which he
describes as 〃a bay of salt water； sixty or seventy fathoms deep；
four miles in breadth；〃 and about fifty miles long； surrounded by
mountains； observes； 〃If we could have seen it immediately after the
diluvian crash； or whatever convulsion of nature occasioned it；
before the waters gushed in； what a horrid chasm must it have
appeared！
〃So high as heaved the tumid hills； so low
Down sunk a hollow bottom broad and deep；
Capacious bed of waters。〃
But if； using the shortest diameter of Loch Fyne； we apply these
proportions to Walden； which； as we have seen； appears already in a
vertical section only like a shallow plate； it will appear four
times as shallow。 So much for the increased horrors of the chasm of
Loch Fyne when emptied。 No doubt many a smiling valley with its
stretching cornfields occupies exactly such a 〃horrid chasm；〃 from
which the waters have receded； though it requires the insight and
the far sight of the geologist to convince the unsuspecting
inhabitants of this fact。 Often an inquisitive eye may detect the
shores of a primitive lake in the low horizon hills； and no
subsequent elevation of the plain have been necessary to conceal
their history。 But it is easiest； as they who work on the highways
know； to find the hollows by the puddles after a shower。 The amount
of it is； the imagination give it the least license； dives deeper
and soars higher than Nature goes。 So； probably； the depth of the
ocean will be found to be very inconsiderable compared with its
breadth。
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 plow。
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。
Of five coves； three； or all which had been sounded； were
observed to have a bar quite across their mouths and deeper water
within； so that the bay tended to be an expansion of water within
the land not only horizontally but vertically； and to form a basin
or independent pond； the direction of the two capes showing the
course of the bar。 Every harbor on the sea…coast； also； has its bar
at its entrance。 In proportion as the mouth of the cove was wider
compared with its length； the water over the bar was deeper compared
with that in the basin。 Given； then； the length and breadth of the
cove； and the character of the surrounding shore； and you have
almost elements enough to make out a formula for all cases。
In order to see how nearly I could guess； with this experience；
at the deepest point in a pond； by observing the outlines of a
surface and the character of its shores alone； I made a plan of
White Pond； which contains about forty…one acres； and； like this；
has no island in it； nor any visible inlet or outlet； and as the
line of greatest breadth fell very near the line of least breadth；
where two opposite capes approached each other and two opposite bays
receded； I ventured to mark a point a short distance from the latter
line； but still on the line of greatest length； as the deepest。 The
deepest part was found to be within one hundred feet of this； still
farther in the direction to which I had inclined； and was only one
foot deeper； namely； sixty feet。 Of course； a stream running
through； or an island in the pond； would make the problem much more
complicated。
If we knew all the laws of Nature； we should need only