i88o.] 
Analyses of Books . 
273 
Studies on the Seat of the Russo -Turkish War of 1877-78.* A 
Report of Swiss Engineer Officers on their Mission to the 
Seat of War in 1878, as presented to the Swiss War De- 
partment. By C. Ott, Colonel of Engineers. Zurich : 
Orell Fiissli and Co. 
We have here a minute criticism of the operations of the con- 
tending powers from a purely professional point of view. The 
author infers that the defence of a country requires fortified 
central positions, in order that all may not be lost with the fall 
of external lines of defence, and that a prolonged resistance and 
a resumption of the offensive may be possible. These chief 
places of arms serve both for the protection of important towns 
and for supporting the movements of the army. The chief de- 
fence of such positions must lie in detached forts and outworks, 
the strength of the fortifications be reduced internally. The 
fundamental idea is the establishment of fortified radii. It is 
economical, as far as possible, to substitute inanimate masses 
for living defences, — a view which has its especial signification 
for Britain, whose armies are relatively small in comparison with 
its financial resources. Such external detached forts, Col. Ott 
considers, should be prepared in time of peace. He holds that 
in case of war the Swiss Landwehr would find its proper function 
in the defence of such entrenched positions. 
This work evidently merits the careful attention of military 
men in England. 
A Criticism of Dr. CrolVs Molecular Theory of Glacier Motion « 
By J. J. Harris Teall, M.A., F.G.S. London: Simpkin 
and Marshall. 
The author contends that in his work “ Climate and Time ” Dr. 
Croll uses terms^such as conduction, radiation, and molecule — 
in various senses in which they are not employed by physicists, 
and “ applies the results of physical research, expressed in lan- 
guage in which the terms are used in one definite sense, in sup- 
port of a theory in the statement of which the same terms are 
used in a different sense.” He contends that the entire theory 
is based upon an ambiguous use of the word “ molecule.” Dr. 
Croll attributes, e.g., to the molecules the property of capillarity. 
* Studien auf dfcm Rriegs schauplatse des Russisch-Turkischen Krieges. 
