world as a machine (_Erdkunde_).

It is for the same reason that Seismology and Vulcanology make little
progress; the first cannot be pursued beyond its present boundaries, nor
can even its present position be understood or explained by anyone
unfamiliar with the laws of wave motion, of all classes of waves; and it
would be easy to show, by quoting from various British or foreign
text-books on Geology, how extremely imperfect is the grasp of some of
the authors upon the subject of earthquake-wave motion, even such as
they admit and endeavour to explain and apply: in fact, many geologists
appear never to have framed to themselves any clear idea of what _is_ a
wave of any sort, liquid or elastic. The general silence as to seismic
theory of French geological writers is remarkable, to whatever cause
attributable. It has been said that French philosophers show themselves
little disposed to acknowledge or to follow the lead of their foreign
compeers in any branch of science. If this be true, or in so far as it
may be so, it is unworthy of French science, which has such boundless
claims upon our homage. I am disposed to attribute the fact in this case
to other circumstances; and, amongst these, to the small extent to which
our language is known amongst French scientific men.

Germany has shown more desire to cultivate this branch of science.
Although, as yet, the distinct enunciation of its fundamental principles
has but sparsely found its way into her text-books, several able
monographs, such as those of Schmidt and of Hoettinger, prove how
completely some of her philosophers have mastered and how well applied
them. The men of science of Northern Italy, amongst whom so many
glorious names are to be found on the roll of discovery, have shown
themselves quite alive to the importance of Seismology; and I know of no
more clear, exact and popular exposition of its principles and
application, and of its cosmical relations, than is to be found in a
small volume by Professor Gerolamo Boccardo, published at Genoa in 1869,
entitled _Sismopirologia Terremoti, Vulcani e lente oscillazione del
suolo, saggio di una teoria di Geographia Fisica_.

My object, so far, has been to mark the progress of ascertained
theoretic notions as to Seismology. I have, therefore, passed without
notice many speculative monographs, and the treatment upon Earthquakes,
whether speculative or historical, and however able, that constitutes a
prominent feature o