ADJUNCTS OP DEFENCE. 
465 
be no reason why it should not stand alone. It will not, however, 
obviate the necessity for providing some fire over interior waters, nor 
will it enable precautions against torpedo-boat attack to be dispensed 
with. 
Broadly speaking, therefore, the torpedo must be regarded as a 
means of denying certain limited waters to armoured ships. The first 
question to be considered in any specific case is whether an enemy has 
anything to gain by placing armoured ships in such waters, or attempt¬ 
ing to pass them at speed. This question is essentially naval, and lies 
wholly outside of the legitimate sphere of the technical expert. When 
it has been answered in the affirmative, a prima facie case for a Brennan 
installation arises. 
Fixed installations on shore have so far been dealt with. Such 
installations have the apparent disadvantage that their positions are 
certain to be accurately known in advance by an enemy. Where, 
however, the installation is properly sited and arranged, this disadvan¬ 
tage is of small account, since the torpedo can be freely used outside 
the zone of its vulnerability. By establishing it close behind a con¬ 
spicuous building, which would be partially destroyed by a single 
projectile from the bow armament of an advancing vessel, all possibility 
of usefulness in war would be abandoned. 
Assuming that a floating installation can be rendered as satisfactory 
as one on shore, the general conditions laid down remain practically 
unchanged. If the Brennan vessel is to be used at anchor, the 
advantage of the unexpected may be attained and the scope of action 
of the torpedo may be somewhat extended. If it is to be manoeuvred 
against an enemy, it becomes a vessel of war with which we of the 
army have nothing whatever to do. 
The two adjuncts above discussed are both capable of rendering 
valuable aid to the defence when employed with due regard to their 
limitations and to the outstanding requirements of British ports. 
Such aid is, however, in both cases, available only against purely naval 
attack, i.e ., attack by ships apart from operations on shore. This form 
of attack found little favour in the past wherever moderate coast 
defences, manned by trained gunners, existed. It is even less likely 
to be attempted in future now that ships are fewer, far more valuable, 
and, for the most part, relatively more vulnerable. Against an Algiers, 
an Acre, an Alexandria, it may unquestionably continue to play a part 
in war. Against the existing defences of British ports it is the least 
probable policy for an intelligent enemy to adopt. Such risk as they 
may run lie in other directions, and of such risks torpedo-boat attack 
at the outset of war is the greatest, although it applies to certain ports 
only. Here neither the position-finder nor the Brennan torpedo pro¬ 
mises any assistance to the Empire. 
Many of the principles which the writer ventured to urge as regards 
the employment of submarine mines have subsequently received official 
sanction. Achit omen . 
