126 Reviews—Bryson’'s Trip to Iceland. 
thousands of feet of upheayed mountain, most of the eruptions of the 
European series were either submarine or only at moderate elevations 
above the sea. The basalt of the north-east of Antrim and the 
Western Islands of Scotland are examples of some of the earlier 
outbursts. The Faroe Islands are more modern, and Iceland is still 
among the localities from which molten rock is poured out. It is 
impossible, therefore, to pass by without notice any really honest 
account of Icelandic phenomena by a competent observer. 
The Geysers and the Strokr, those singular examples of intermit- 
tent fountains of boiling water and steam, were, however, the only 
objects that the shortness of the author’s visit allowed him to study. 
He found the Great Geyser basin to measure 74 feet by 68, the 
temperature of the water in it varying from 176° to 179° F. The 
depth of the tube was 70 feet on one side, and 64 on the other. 
With thermometers specially contrived so as to lose part of the 
mercury when exposed to a temperature above’ 212°, he and his 
companions determined the temperature of the bottom of the tube, 
not long before an eruption, to be 240°, while the temperature half- 
way down was in one case as high as 270°. Not only this, but every 
important fact known concerning the district proves that the causes 
of disturbance are purely local, and that they are probably produced 
by chemical action. The explanation given by Bunsen is supported 
by Mr. Bryson’s observations. ‘The absence of organic matter in the 
Geyser water was proved by the use of permanganate of potass, and 
is a fact not without importance. 
The Strokr erupts when turf and stones are thrown into its funnel, 
and very rarely without such provocation. Mr. Bryson suggests, as a 
reason, the floating of mechanical particles on the surface of the 
water already boiling, and the consequent incapacity of the steam to 
escape into the air without bubbles, which in this case are represented 
by an eruption. He illustrates the case by the behaviour of water 
boiling in a vessel where a broken egg supplies a film of albumen. 
It is suggested that the phenomena of the Geysers are probably 
modern. ‘The measurement of the siliceous sinter of the Great Gey- 
ser by Capt. Forbes would give an age of about a thousand years; 
and this estimate is somewhat strengthened by the fact that there is 
no notice of this spring in the earlier days of the colonization of 
Iceland, 986 years ago. 
ADDRESS AT THE ANNIVERSARY MEETING OF THE RoyaL GzEO- 
GRAPHICAL Society, 23rd May, 1864. By Sir Roperick I. Mtr- 
cHison, K.C.B., G.C.St.A. & Sr.8. D.C.L., LL.D., F.R.S., 
Director-General Geological Survey, Presipent. London, 1864. 
8vo. pp. 89. 
oe presentation of the royal awards to Baron Charles von 
Decken and Captain Grant, the Obituary Notices, and the report 
of progress in British and Foreign Geography constitute, of course, the 
bulk of this interesting Address ; but there is one section in it of 
especial interest to Geologists, namely, a notice of the Glaciers of 
the Himalayan Mountains and New Zealand, as compared with these 
