Journey through South, North and East Iceland. 163 
east side of Liosavatn, the stream-lava begins. We ascended 
from Skalxandafliot to the heath of Fliots, and passed through 
a long desert track of volcanic-sand to Myvatn, where a fright- 
ful scene of volcanic destruction was ornamented by beautiful 
groupes of volcanoes. On the east, the majestic Herdabried * ; 
on the south-east from Myvatn, the Blafell, Burfell, Skogama- 
nafell ; on the north-west, Krabla, Hleirnuker, Eylifurfell, Gies- 
dallsfell, Gusedallsfell, which surround the smoking white sul- 
phur mountain of Namafell ; on the south, the Seltlandafell ; 
and on the north-west, the peaked Uindbelgias, with the nume- 
rous insular-looking eminences in the Myvatner lake, form a 
circle of volcanic mountains exhibiting^ every variety of form* 
The lava streams of Heirhnuker, and the great black crust of vol- 
canic sand of Vogum, present a frightful appearance. We travell- 
ed over this dreadful volcanic desert, until we reached Vopnafiord 
in Easter Iceland. The lavas, as far as Liosavataj were entirely 
basaltic ; those of Hleirhuker somewhat porphyritic ; while those 
of Herdubreid were the same as those of Eyafialla-Jokull. Ba- 
salt, amygdaloid and trap-porphyry, extend from Hoff in Vop- 
nafiord across the heath of Smorvatn. The Valley of Fliot is 
an extensive district of columnar basalt and porphyry, through 
which the rivers Jokullsau and Lagerfliot have cut their channels* 
Wacke and amygdaloid are again the predominating rocks, from 
the Valley of Zungen across the heath of Eskifiard to Eskifiord. 
The whole mountain-chain cm the north side of Rhodefiord, which 
is composed of beds of amygdaloid, calcedony-wacke, trap-porphy- 
ry, and stilbite-wacke, terminates at the Grakall, in the form of 
an ironshot calcedony-wacke, which rests on clinkstone-porphyry. 
The bed of stilbite-wacke often contains large cavities, which are 
filled with that beautiful variety of calcareous-spar named Iceland- 
crystal, or double refracting spar. The calcedony-wacke is either 
ironshot, when it contains jasper, stalactitic calcedony, and crys* 
tals of quartz ; or it is without iron, and then we find, in place 
of the jasper, opal and calcedony. The beds of clinkstone-por- 
phyry alternate with obsidian, pitchstone and pearlstone porphy- 
ries ; and this formation appears to form the basis on which all 
* Henderson gives a representation of Herdabried and the vicinity, in a plate in 
his first volume. — Ed. 

