October 16, 1915. 
LAND AND .WATER. 
A NOTE ON THE POSSIBILITY OF 
CHECKING THE ENEMY ON THE 
RAILWAY BEYOND NISH. 
The idea, that the railway beyond Nish into 
Bulgaria can be put out of action easily by our 
Allies and that in this fashion the advance upon 
Constantinople might be long delayed is unfor- 
tunately erroneous. 
It may be worth while in this connection to 
examine what the interruption of railway com- 
munication is according to modern experience, 
and how far it can apply to this all-important line 
which is the great avenue to Constantinople, 
especially to that essential section of it between 
Nish and the Bulgarian frontier, which can, pre- 
sumably, be held by our Ally to a somewhat later 
date than the rest. 
A railway line, surveyed, engineered, and 
built, is not susceptible of complete destruction 
save in a length of time and at an expense of 
labour not to be thought of in the ordinary opera- 
tions of war. Rails removed can be rapidly re- 
laid, occasional settlement through blasting in 
cuttings, and gaps through blasting in embank- 
ments do not take very long to set right. 
There are, in effect, but two vulnerable 
elements in this kind of communications, to wit, 
bridges (including trestles or archways over 
mr.rshes) on the one hand, and tunnels on the 
other. 
Tunnels are far less liable to prolonged inter- 
ruption than might be imagined. The degree of 
their vulnerability depends largely upon the soil 
through which they pass. But in much the 
freater number of cases the portion of the tunnel 
alien in as a result of explosion can be set right 
in no very gre?.t delay. 
Bridges over ravines and rivers, and cause- 
ways over marshes are the real weak points. Not 
embankments, for an embankment can hardly be 
destroyed with sufficient rapidity. 
Now, it is obvious that the gravity of the in- 
terruption caused by the destruction of a bridge 
dejjends upon the opportunities the enemy ha.s for 
replacing the destroyed portion, and that, there- 
fore, the length of the interruption will be con- 
ditioned by these things, the industrial condition 
of the enemy, his own communications leading up 
to the wrecked bridge, and the type of gap he 
finds when he comes to mend it. 
The most formidable interruption of a rail- 
way line by far is obviously the destruction of a 
high bridge with broad spans. To replace such 
an element means long engineering preparation 
and execution. Meanwhile the trans-ship- 
ping of goods across either a ravine or a river — 
especially if the latter be rapid - — is a heavy 
handicap. The smaller the spans, the lower the 
height, the shallower the stream across which the 
bridge is built, or the slower its current, the less 
formidable is the interruption caused. 
To these points must be added what is as 
true of blowing up tunnels as if is of destroying 
spans of bridges, that the element of numbers is 
exceedingly important. If, for instance, in a 
railway through a gorge you have 50 sliort girder 
bridges and 50 short tunnels in a space of 20 miles, 
and you blow up all the bridges and all the tun- 
nels,' j'ou will have interrupted your enemy's 
advance quite as much or more than you would 
have done by blowing up one high broad-span 
bridge across a deep and rapid river. 
Now, when we examine the railway line 
between Nish and the Bulgarian frontier (a 
matter of only 50 miles as the crow flies and of not 
more than 70 miles, perhaps, by the rails) we find 
no serious opportunities of interruption at all. 
The railway everywhere follows the valley of the 
Nisava, and this stream rises beyond the Bul- 
garian frontier; so that there is no climbing by 
works up a pass or going through a long tunnel 
under a pass in its Serbian portion. 
station 
Sr^e Tmmd Bridge 
The part nearest the frontier, and between 
that boundary and Pirot station, passes through 
an upland plain of the river running perfectly 
level along a straight piece of highway that goes 
by the side of the railway. Just below Pirot at the 
point marked A on Sketch IV. there is a very 
short tunnel and two insignificant bridges, all 
three of which elements are constructed to carry 
the railway through one of those spurs of a hill 
which make a bend in the course of tiie highland 
stream. An artificial gap here would not interrupt 
the use of the line for more than a couple of days. 
Just outside Bela Palanka station (at B) 
there are also two bridges, quite short, carrying 
the railway straight over a loop in the Upper 
Nisava stream. 
Below Bela Palanka, in the gorge of the 
Nisava (which is, roughly, the bulge marked 
Y.Y.Y. on the above sketch), there is but one 
bridge across the stream (at about C), which is 
here narrow, and there are, I believe, no tunnels. 
Finally, on the exit from the gorge there is 
one bridge across the Nisava, about 8 miles east of 
Nish (at D). There are then but four vulnerable 
points in the whole of this trajectory, and these 
are quite insignificant as serious obstacles to an 
enemy's advance. 
We must, I fear, reject any hope of checking 
the enemy through the destruction of this section 
of the line. 
H. BELLOC. 
One of the most interesting and at the same time one of 
the most instructive works on the Napoleonic campaigns is 
Ilow V/art Were Won, by George T. Warner, M.A. (Blacki* 
and Son, Ss. net), which embodies a series of lectures de- 
livered on Napoleonic strategy at Harrow, to the elder half 
of the Officers' Training Corps. The author has been quick 
to seize the salient points of the great conqueror's campaigns, 
and above all he has laid due stress on the two military 
essentials of speed and preparedness. Valuable as his work 
is, it is no dry and dull study, but each chapter of the book 
is a story well told. The book is one that will count among 
Napoleonic literature. 
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