Jökull - 01.12.1960, Blaðsíða 10

nicht zu Geniige untersuchen können” (pp. 18
-19).
This story — and there is no reason to doubt
it — tells us of a rather remarkable enterprise
of an Icelandic farmer about the middle of
the 17th century or somewhat earlier, an at-
tempt to explore Vatnajökull. From the travel
account it seems likely that he crossed the
eastern part of Vatnajökull and that the moun-
tain he saw was the extinct volcano Snæfell.
Vídalín’s treatise, which is dated July lst,
1695, was not published until 1754, and then
in the German translation quoted here, done
by a relative of his, Páll Bjarnason Vidalin,
and printed in Hamburgisches Magasin, Ham-
burg und Leipzig 1754, pp. 9—27 and 197—210.
The translator adds some comments of his own
and among other things discusses the annual
stratification of the ice (op. cit. pp. 211—212),
clearly without knowing J. H. Hottingers paper
of 1703 (Montium glacialium helveticorum de-
scriptio) where the annual stratification of the
firn on Grindelwaldgletscher is correctly ex-
plained.
In a note book called Chorographica Islandica
(AM 213 8°) the famous founder of the Arna-
magnæan Collection in Copenhagen, Arni
Magnússon (1663—1730) has written down a lot
of memoranda on the topography and general
geography of Icelancl during his travels of in-
spection through the country 1702—1712. The
note book contains some interesting particulars
on glacier changes. It also contains a sketch
map of Sólheimajökull (Fig. 4) and a very full
description of glacierbursts (jökulhlaups) caused
by a lake dammed by that glacier. The fol-
lowing is quoted from that description: “Sól-
heimajökull is a flat, low outrunner from Mýr-
dalsjökull, extending in a bend southwards
from the glacier and then to the W. When in
the beginning it was growing towards the west
it met and filled a canyon, continuing after-
wards towards the W......A glacier river runs
through this canyon under the N margin of the
glacier, subsequently appearing from its S mar-
gin, where it flows out as through a tunnel.'Fhis
tunnel is occasionally blocked, making the river
smaller than usual. The reason for this is the
stoppage of that part of the river which other-
wise runs underneath the ice from Mýrdals-
jökull itself. When the tunnel is stopped up,
the water, which otherwise would have run out
of tlie canyon mentioned above, forms an
enormously deep lake. When the ice blocks
stopping up the tunnel can no longer with-
stancl the pressure of the water, the tunnel is
opened cum impetu, and everything inside it
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