reason o f the great superiority of Dannemora iron over every other
species with which we are acquainted.
The iron mine o f Dannemora lies in a hill so little elevated above
the surface of the neighbouring country, as easily to escape observation.
It may be nearly two English miles in length, and not quite half
a mile in breadth. It is almost surrounded by lakes: the lake of Dannemora,
of Films, and of Grufve (mine), lying quite contiguous to
it; that side which is not enclosed by water is a moss, where turf is
dug: this turf has been tried as a fuel for smelting the ore; but has
been found greatly inferior to the turf in other parts of Sweden. The
iron ore occupies a very large vein in, this hill, which runs in a northwest
and south-east direction.
The mine of Dannemora has been Wrought for these 300 years and
more; for the exact period of its origin is not certainly known. It
was first wrought as a silver mine: the silver being extracted from
galena, which is still found in the vein, though in very small quantity.'
The galena, as far as I could learn, occurs only in the sodra grufva.
This source of emolument soon fading, or becoming unproductive, the
iron ore began to be extracted and smelted, and the goodness of the
iron obtained gradually drew to it the attention of the, public. At first
it was the property of the King of Sweden, who consigned it over to
the Archbishop of Upsalaas a part of his revenues.. At present it, belongs
to a number of private individuals, who work it separately,.each
on his own account. The nature of the situation is such, that water,
cannot be procured to drive the requisite machinery. On that account
they have been obliged to erect a steam engine, without which, I was
told by the mine master, it would have been impossible to have continued
to extract the ore. Some years ago the mine was overflown by
a great inundation o f water from the neighbouring lakes. To prevent
such an inconvenience from- recurring, a strong stone wall has been
built, at a considerable expense, to keep off the water.
When you go to the side o f the mine you find a great opening*
about 50 fathoms deep, and perhaps 50 feet wide. From the bottom.
o f this opening, which has been formed by the extraction of ore, you
enter into the mine by a passage which does not extend a great way.
I did not descend farther, but was told that the mine was wrought
about 30 fathoms deeper than this opening. The ore is blasted out
with gunpowder. The vein is distinguished by three distinct names,
according to its situation and the quality o f the ore which it yields.
For, though all the Dannemora ore is good, there are some portions of
it much better than others. That part of the vein which lies under,
the great opening, which constitutes the mouth o f the mine, is called
stor rymning. It constitutes by far the greatest, portion of the mine.
The next portion is called jdrd grufva, (earth mine), and it yields the
ore of the very best quality. The farthest south portion is called
sodra grufva, (southern mine), It, yields the worst kind of ore of all
the three, probably because it is mixed occasionally with galena and
blende.
The rock in which, the Dannemora vein runs, as far as I could learn,
is quartz. But I had no opportunity of examining it, as I could find
no portion of it laid bare. The substance immediately contiguous to
the vein appeared, to me to possess the characters of horn-stone, and
to contain hornblende. The Swedes call it hdllejlinta, a name under
which they confound quartz, horn-stone, and compact felspar. The
iron ore itself is mixed with lime-stone, with quartz, with actinolite;
and, chiefly in consequence of these mixtures it varies very much, in the
quantity of iron which it yields. Sometimes it produces only 25 percent.
of cast-iron, sometimes as much as 75 per. cent. In the sodra
grufva ore I saw specimens o f blende, sometimes so intimately mixed
with the iron, ore; that the eye could only detect , its presence by
the colour and aspect; at other times in distinct masses of considerable
size. In the same ore I saw likewise fluor spar, galena, and
amethyst, but all of them in such small quantities that they are considered
as rarities. The lime-stone contains a mixture o f manganese,
and from the aspect of the iron ore itself one would be. apt to suspect
the presence of the same mineral in it. I do not believe that the
Dannemora ore has ever been analysed, which is a very odd circum