LAND AND WAT E R 
Janj'ary 20, 1916 
and when most nations had the same advantages in 
them, when transport by sea was precarious and 
dependent upon tlie wind, it was legitimate, as a 
rough rule of thumb, to measure the distance by 
the land map and call that man the possessor of' 
interior linos whose conmiunirations to the various- 
parts ot his front were the shorter in mere miles. 
it is the method Napier uses in his diagrams. It 
was the ob\'ious one for his time. To-day this 
is not the case. Districts differ widely in the 
amount of railway Accommodation they have-and ' 
a railway has many-fold the capacity of a road. 
They also differ very widely even in road accommo- 
dation. Again, railway's having grown' ixp mainly 
on commercial lines and not for strategic reasons 
have very different strategic' values." Again, 
the amount of rolling stock, lacking which mobility 
is at once affected — is an important element in 
the problem. Since the possession of interior 
lines and all the multiplications of power given by 
such a possession lies in the factor of time, and 
not of distance, it very often happens under 
modern conditions that one party to a struggle 
possesses interior lines although on the map they 
seem to be exterior. We have had a tremendous 
instance of this on a large scale in the great Polish 
salient originally in "the hands of the Russian 
armies. 
you saw along the Austro-German lines a whole 
railway system as in Sketch III, whereby the 
great trunk lines A A A could bring up troops 
and materials from the bases within Austria 
and Gerpiany to the front. While all along 
'then- positions at that front a lateral line B B B 
with feeders at C C C" going out from it, per- 
il yoii merely drew the position of the 
Russian armies on the map in the earlier phase 
of the war you saw them occupying a great bow 
from East iPrussia to the Carpathians, as on the 
line A A A on Sketch II, and faced b\' German 
and Austrian forces as along the line B B B ; the 
situation nearly, but not exactly, corresponding to 
the old political frontier which bulged out between 
Russian Poland and the German and Austrian 
Empire. But the Russians did not possess 
" interior lines " at all, as they appeared to 
do upon the map, because their communications 
were so unsuited to concentration. If, instead 
of considering the curve of the forces, \ou were 
to consider the nature of the communications. 
mitted a very rapid concentration at any desitea 
point. The Russians on the other side Had 
only three divergent railways in the fashion 
of the arrows D D D to help them and no trans- 
verse hues at all, such as the dotted line e e repre- 
sents. They could not concentrate upon any 
one point without either going right back to dis>' 
tant raiKvay centres where the lines converged, or 
marching their msn across country. Therefor^ 
when you represent the problem in terms of time the 
Austro-Germans could always concentrate such 
and such a number of men at such and such a 
point upon the front in much less time than the 
Russians. Therefore, in spite of the fact that on 
the map the Austro-Germans held the outside of a 
semicircle, they were, in fact, " possessed of 
interior lines." 
When we have once grasped the truth that 
the possession of interior lines is an advantage 
measured in terms of time, and is an advantage in 
mobility alone, we can appreciate in how very 
high- a degree the present phase of the war in the 
Levant, properly handled, favours the Allies. 
The Allies at this moment possess in that field 
of action (defining the Levant as the countries 
bordering the Eastern Mediterranean) three 
formidable elements of advantage in mobility, 
each one of which gives them the possession of 
interior Hues : that is, the power of concentrating 
at any point of action with greater mobility than 
the enemy. 
These three factors arc : — 
(i) Conhguration of the coast. 
(2) The monopoly of sea communication. 
(3) The lack of homogeneity and the lack of 
good communications upon the enemy's exterior 
lines. '"''■ 
The following Sketch IV will show what I 
mean. 
(i) A mere glance at the outline of the Eastern 
Mediterranean sliows that if that Sea from the 
Straits of Otranto to the shores of Syria be 
