1897] 55 
SOME NEW BOOKS 
Our DEAD VOLCANOES 
Tur ANCIENT VOLCANOES OF GREAT BRITAIN. By Sir Archibald Geikie, F.R.S.  8vo. 
2 vols., pp. xxiv. and 478, and pp. xvi. and 492. With 7 folding maps and 383 
illustrations. London: Macmillan & Co., 1897. Price, 36s net. 
THIS work is an expansion of the two addresses given by its author to 
the Geological Society of London in 1891 and 1892. Those of us who 
have often marvelled at the amount of detail, largely new, that was 
brought into the compass of the addresses, may have foreseen the solid 
and permanent character of the two large volumes now before us. 
In earlier years, Sir Archibald Geikie spent his leisure in volcanic 
areas—travelling, observing, correlating, and storing up the wealth of 
information which is now made orderly and accessible. The 270 
pages—more than a quarter of the whole work—devoted to the 
Devonian, Carboniferous, and Permian volcanoes of Scotland will be 
welcomed on these historic grounds. And in later years, with the 
resources of the Geological Survey at his command, the author has 
been able to extend his area, so as to examine the whole range of vol- 
canic phenomena in our islands. Ireland is not mentioned in the 
strict title of the work, but is in reality dealt with in a manner that 
atones for a great many omissions on the part of British text-books. 
We have here, in fact, a basis which must be consulted before work is 
begun on any igneous rocks of the British Isles, for Sir Archibald 
frequently, and very properly, treats of holocrystalline and deep-seated 
masses in addition to the volcanic relics associated with them. 
So far as we can judge, the passages compiled from previous writers 
have been drawn up with admirable accuracy, even to the use of the 
rock-names employed in the original papers. These. names, in fact, 
would sometimes be the better for a little comment or revision, as in 
the case of the French rock-term ‘labradorite,’ imported on p. 29. 
The book is, however, written for geologists, and largely for those 
engaged in actual investigation ; it has, at any rate, the merit of offer- 
ing no encouragement to young persons ‘reading’ for examinations. 
While book i. is of a general character, there is much in it that is 
admirable and suggestive to the worker in the field. We may note, 
for instance, the diagram of “ the gradual emergence of buried volcanic 
cones through the influence of prolonged denudation” (p. 75). The 
characteristic structures of igneous rocks are described, and are illus- 
trated by photographs from actual specimens. The polished surface 
of ‘ Napoleonite’ on p. 22, and the fluidal Antrim rhyolite on p, 23, 
are perfect examples of their kind. 
It is surely, however, an undue extension of terms to call the 
structure of ‘ Napoleonite’ variolitic ; and we could wish that vario- 
litic and orbicular structure had not been separated from spherulitic 
in the text. The ophitic structure, again, is referred to, as in so many 
