Full resolution (JPEG) - On this page / på denna sida - Pages ...
<< prev. page << föreg. sida << >> nästa sida >> next page >>
Below is the raw OCR text
from the above scanned image.
Do you see an error? Proofread the page now!
Här nedan syns maskintolkade texten från faksimilbilden ovan.
Ser du något fel? Korrekturläs sidan nu!
This page has never been proofread. / Denna sida har aldrig korrekturlästs.
VON TROIL’S LETTERS ON ICELAND. 693
which is thought the greateft amongft all the French water-works, cafts up a thin
column eighty feet into the air: whilft fome {prings in Iceland pour forth columns
of water, of feveral feet in thicknefs, to the height of many fathoms ; and many affirm,
of feveral hundred feet.
But without relying upon what has been faid by others of thefe wonderful phzeno-
mena of nature, I think myfelf happy to have contemplated with mine own eyes the
moft remarkable of thefe {prings, which has enabled me to give you an accurate ac-
count of it. I only beg leave to fay fomething of them in general, before I treat of
that which I faw in particular.
Thefe fprings are of unequal degrees of heat. From fome the water flows gently as
from other {prings, and it is then called /awg, a bath; from others, it fpouts boiling
water with a great noife, and is then called Aver or kittel (keffel). Though the degree
of heat is unequal, yet I do not remember ever to have obferved it under 188 of Fahren-
heit’s thermometer. At Laugarnas we found it at 188, 191, 193. At Geyfer, Rey-
kum, and Laugarvatn 212; and in the laft place, in the ground, at a little hot vein of
water, 213 degrees.
It is very common for fome of the {pouting fprings to clofe up, and others to {pring
up in their ftead ; there are likewife frequent traces of former Avers, where at prefent
not a fingle drop of water is to be feen. Many remember to have feen inftances of this ;
and Egbert Olafsen relates, that in 1753 a new Aver broke forth at Reikakio, feven
fathoms in breadth, and three in depth, at the diftance of fifty fathoms from an old
fpring, which had been ftopped up by a fall of earth. Frequent earthquakes and fubter-
ranean noifes, heard at the time, caufed great terror to the people who lived in the
neighbourhood.
All thefe hot waters have an incrufting quality, fo that we very commonly find the
exterior furface from whence it burfts forth covered with a kind of rind, which almoft
refembles chaced work; which we at firft took for lime; but we foon became dubious
of this, as it did not ferment with acid ; but we hope that you, Sir, will foon refolve us.
This cruft isin general very fine ; but it is, however, moft pure and clear at the fpout-
ing fprings ; for at the others, where the water flows, the parts precipitated by the
water are fometimes mixed with earth, which makes the cru{t appear darker.
At the Avers it is very difficult, nay almoft impoffible, to examine within the opening
the difpofition of the paflage which the water has formed, both by reafon of the heat of
the water, and the violence with which it is forced out. One may, however, with con-
fidence judge of the great by the fmall: and it gave us the greater pleafure, as we had
an opportunity at Laugarnas to examine the vein of water itfelf a confiderable way
under the crutt.
The water had in this place taken its courfe through a bright grey clay, the furface
of which was covered with a white rind; but was on the fide neareft the clay, quite
fmooth, and crifped on the upper fide. ‘The vein flowed a good way under this cruft,
through a canal formed of a fimilar matter ; and the whole canal was filled with cryf{-
tals, which had a very pleafing effet. I had not time to examine their nature and
form on the fpot, as they were very {mall ; but I expect a more particular account of
this fubject from you, as you will find feveral {pecimens of them in the collection I fent
you. We could not, however, purfue the courfe of the water very far, as we were
ebliged to leave it to its fubterranean paflages, through which nature had feduced it from
its refervoirs, where heated by the warmth, and comprefled by the exhalations, it at laft
bur{ts from its prifon, by gufhing forth at another place, in order to make way for its
vapours.
The
<< prev. page << föreg. sida << >> nästa sida >> next page >>
