COAST DEFENCE AGAINST TORPEDO-BOAT ATTACK. 25 
central station ; the others, and some of the batteries, worked in¬ 
dependently and the lights in consequence often prevented the low 
sited guns seeing to fire. I take for simplicity's sake only three 
lights, all low sited and five 2-gun Q.F. batteries at various heights. 
MOO' 
CENTRALS STATION 
D 
C 14000* 
4.4 AOO’ 
PIG.I. 
-a- 
Thus R and $ are, in accordance with existing engineer methods, 
fixed lights. T was a wandering beam rigged up ashore by the Navy, 
beautifully worked by their men, and under the complete control of 
the central station by means of an electric bell. It, too, was low 
sited, but slightly higher than the two fixed lights. With the selection 
of position of electric lights the artillery have unfortunately nothing 
to say. The example given is perhaps an instance of the worst 
possible arrangement, but is all the more instructive. The attack was 
made by four boats. 
The night—pitch dark. The two batteries, A and B , can see 
nothing outside the fixed rays R U, S U, being blinded by these fixed 
lights, and they are useless until the boats run through the fixed 
beams. E is also blinded when the wandering ray moves to the 
southward. Suppose a boat t.b. 1 is picked up in the wandering ray T. 
C and D, seeing over the fixed rays R TJ } S U, and E at once open 
fire. The three batteries see many splashes (say c, d, e ,) but none of 
them can tell which are its own splashes, and each is apt to alter 
wrongly. Seeing an absence of splashes in the exact neighbourhood 
of the boat, the central authority touches P's and E’s bell, and they 
