noon-day nightmare, and to think of having
climbed it crisps all the fifty-six joints of one's twenty digits.
While I was on it, "pinnacled dim in the intense inane," a strong wind
was blowing, and I felt sure that the spire was rocking. It swayed back
and forward like a stalk of rye or a cat-o'nine-tails (bulrush) with a
bobolink on it. I mentioned it to the guide, and he said that the spire
did really swing back and forward,--I think he said some feet.

Keep any line of knowledge ten years and some other line will intersect
it. Long afterwards I was hunting out a paper of Dumeril's in an old
journal,--the "Magazin Encyclopedique" for _l'an troisieme_, (1795,)
when I stumbled upon a brief article on the vibrations of the spire of
Strasburg Cathedral. A man can shake it so that the movement shall be
shown in a vessel of water nearly seventy feet below the summit, and
higher up the vibration is like that of an earthquake. I have seen one
of those wretched wooden spires with which we very shabbily finish some
of our stone churches (thinking that the lidless blue eye of heaven
cannot tell the counterfeit we try to pass on it) swinging like a reed,
in a wind, but one would hardly think of such a thing's happening in a
stone spire. Does the Bunker-Hill Monument bend in the blast like a
blade of grass? I suppose.

You see, of course, that I am talking in a cheap way;--perhaps we will
have some philosophy by and by;--let me work out this thin mechanical
vein.--I have something more to say about trees, I have brought down
this slice of hemlock to show you. Tree blew down in my woods (that
were) in 1852. Twelve feet and a half round, fair girth;--nine feet,
where I got my section, higher up. This is a wedge, going to the
centre, of the general shape of a slice of apple-pie in a large and not
opulent family. Length, about eighteen inches. I have studied the
growth of this tree by its rings, and it is curious. Three hundred and
forty-two rings. Started, therefore, about 1510. The thickness of the
rings tells the rate at which it grew. For five or six years the rate
was slow,--then rapid for twenty years. A little before the year 1550
it began to grow very slowly, and so continued for about seventy years.
In 1620 it took a new start and grew fast until 1714; then for the most
part slowly until 1786, when it started again and grew pretty well and
uniformly until within the last dozen years, when it seems to have got
on sluggishly.