_e, 
Fan. 11, 1883] 
NATURE 
239 
ject, and must precede all else, while stratigraphical geology 
depends upon all the other divisions, and must follow 
them. Palzontological geology is in some sense co-ordinate 
with dynamical and structural geology taken together, but 
finds place after them because its use cannot be explained 
before their principles are known. Whether dynamical 
geology should precede or follow structural, is a question 
admitting of discussion. They are to a large extent cor- 
relatives, and either is more intelligible if preceded by 
the other. To give precedence to structural geology is to 
describe phenomena in advance of their explanation. If 
dynamical geology precedes, a variety of natural agents are 
described which have no apparent connection with the 
general subject. The majority of writers have selected 
the former alternative ; but a few have preferred the 
latter, and among them our author. All things considered, 
he appears to have chosen the lesser evil. 
The single new departure of the volume consists in the 
elevation of physiographical geology to the rank of a major 
division. The same title it is true has been placed by 
Dana at the head of a primary division of the subject, but 
it was used by him ina different sense. With Dana it 
is a synonym for physical geography ; with Geikie it is 
that ‘‘ branch of geological inquiry which deals with the 
evolution of the existing contours of the dry land.’’ So 
far as the subject has had place in earlier treatises it has 
been regarded as a subdivision of dynamical geology, and 
the classification which placed it there was certainly 
logical. In dynamical geology, as formulated by Geikie, 
the changes which have their origin beneath the surface 
of the earth (volcanic action, upheaval, and meta- 
morphism), and the changes which belong exclusively 
_ to the surface (denudation and deposition) are separately 
_ treated. In physiographical geology the conjoint action 
of these factors of change is considered with reference to 
| its topographical results. Starting from geological agencies 
| as data we may proceed in one direction to the develop- 
ment of geological history, or in another direction to the 
| explanation of terrestrial scenery and topography, and if 
| the development of the earth’s history is the peculiar 
| theme of geology, it follows that the explanation of topo- 
graphy, or physiographical geology, is of the nature of an 
incidental result—a sort of corollary to dynamical geology. 
| The systematic rank assigned to it by Geikie is an 
! explicit recognition of what has long been implicitly 
| admitted: that geology is concerned quite as. really with 
the explanation of the existing features of the earth as 
with its past history. The separation initiated by our 
author is an indication of the growing importance of the 
subject, and it is safe to predict that in the future it will 
not merely retain its new position, but will even demand 
| a larger share of space. 
The following scheme exhibits the general plan of the 
volume :— 
Book 1.—Cosmical aspects of geology. 
Book 2.—Geognosy : an investigation of the materials 
of the earth’s substance. 
Book 3.—Dynamical geology. 
Book 4.—Geotectonic geology ; or the architecture of 
the earth’s crust. (Geotectonic is a new term proposed as 
a substitute for structural). 
Book 5.—Palzontological geology. 
Book 6,—Stratigraphical geology. 
| 
| 
| 
Book 7.—Physiographical geology. 
Comparing this classification with that of other authors, 
and viewing it with reference to the present condition of 
the science, we may say without hesitation that it has no 
superior, and that it is well adapted to existing needs. 
G. K. GILBERT, 
U.S. Geological Survey 
(To be continued.) 
OUR BOOK SHELF 
Uniplanar Kinematics of Solids and Fluids; with A Dpli- 
cations to the Distribution and Flow of Electricity. By 
George M. Minchin, M.A. Pp. viii. + 266. (Oxford: 
Clarendon Press, 1882.) 
IN subject-matter this book is almost unique among our 
mathematical manuals. The only fellow to it is Clifford’s 
“Kinematic.” It consists of six chapters, the first deal- 
ing with Displacement and Velocity, the second with 
Acceleration, the third with Epicycloidal Motion, the 
fourth with the Mass-Kinematics of Solids, the fifth with 
the Analysis of Small Strains, and the sixth almost as 
long as the others put together, with the Kinematics of 
Fluids. The subdivisions of the last chapter are headed 
—General Properties: Multiply Connected Spaces ; 
Motions due to Sources and Vortices, Electrical Flow; 
Conjugate Functions. There is also a short appendix, 
with notes on such subjects as Vectors and their Deriva- 
tives, Current-Power, and Routh’s Use of Conjugate 
Functions. 
It is impossible, without occupying considerable space, 
to give an adequate idea of the freshness and originality 
which mark Prof. Minchin’s work. These are notable in 
the exceedingly valuable sixth chapter, but even on such 
well-worn subjects as velocity and acceleration, he treats 
us to many pleasant little surprises. Nor is this accom- 
plished at the expense of the student; the clearness, 
fulness, and good arrangement specially requisite in a 
college text-book are all of them conspicuous ; and valu- 
able collections of exercises, worked and unworked, and 
given at intervals. The book is altogether one for which 
success may be cordially wished, not merely as a reward 
to the author, but in order that the science of which he 
treats may go on as steadily and rapidly advancing as 
it has of recent years been doing. 
Die Kifer Westfalens. Zusammengestelt von F. West- 
hoff. Abtheilung ii. (Supplement zu den Verhand- 
lungen des naturhistorischen Vereins der preussischen 
Rheinlande und Westfalens, Jahrgang 38, pp. 141-323.) 
(Bonn, 1882.) 
WE have already noticed the first part of this work in 
NATURE. The second and concluding portion is now 
before us. It forms one of the most useful local Beetle 
catalogues that we have seen, nicely printed (the names 
being in bold black type), with copious local and other 
information. The district comprises about 450 square 
(German) miles, and is varied in its physical conditions. 
In all, 3221 species are enumerated, in 59 families. The 
Staphylinide comprise 667 species, Curculionide 471, 
Carabide 321, Chrysomelide 265, and Dytiscid@ 115. All 
the other families have each less than Ioo representatives, 
and Io of them less than 5. The nomenclature followed 
is that of the newest “ Stein-Weise”’ German list, which, 
as is well known, has introduced a great multitude of 
changes and innovations ; but other generally received 
names are indicated in brackets, thus avoiding confusion. 
Westhoff describes no new species in Part ii., but indi- 
cates and names a good many new (chiefly colour) varie- 
ties. Probably the rage for naming colour-varieties, so 
wide-spread at the present day, should be deprecated. 
For instance, in this catalogue we find a list of 27 named 
