ri 
TOKPEDOES. 
185 
. i extremities of wliicli are close to, but do not touch, the brass 
. disk, E, connected with the insulated wire. There is therefore a 
break in the circuit between the disk, E, which is in communi- 
cation with the battery and torpedo, and the springs, hhhh, 
which by means of the ring, gg, the uprights, kkkk, and the 
; ! iron foot-plate, B, are in communication with the earth. Now 
’ i when a passing vessel hits the circuit-closer, the upright pen- 
i 1 dulum, BD, is set in motion by the concussion, and the disk 
i ! strikes the springs several times.* At each of these contacts a 
I current passes along the cable, through the fuze of the torpedo, 
I on by the second length of the cable to the disk, e, thence to 
the springs, and by the ring and uprights to the foot-plate, 
' ' which sends the current back to the earth-plate of the battery. 
, In this way the vessel herself closes the circuit and fires the 
I torpedo. When friendly ships are passing up or down the 
H defended channel the battery can be disconnected, and they 
» i will be perfectly safe ; but when an enemy is approaching, the 
I battery can be connected with the wires again, and all the 
I I torpedoes will be ready for action. At night, by using a 
i , current not sufficiently strong to fire the fuzes, and employing 
1 1 a galvanometer, a deflection of the needle will indicate the fact 
j i whenever a circuit-closer is touched, in other words, whenever 
i a ship is passing up the channel. Thus a line of these circuit- 
; I closers acts at night as a line of outposts to a fortified harbour 
t or river mouth. Of course, unless under exceptional circum- 
I ' stances, it would be very dangerous to fire torpedoes in the 
I ^ darkness. 
' ' We have given only a brief sketch of the methods adopted 
I ! in using electrical torpedoes. Nothing has been said of scores 
' ' of ingenious plans for laying down the torpedoes and their 
cables, — for carrying the latter into the operating rooms, — 
! for testing the cables, fuzes, and circuit-closers before and after 
‘ I they are placed in position, — for retaining the power of firing 
the torpedo by disconnecting the circuit-closer, if it is grappled 
by the enemy, — and, finally, for protecting the whole system 
from injury when once it is arranged. On all these points, and 
on many more, much could be said ; but, as our object is only 
to give the reader a general idea of the subject, we must pass 
them by, referring those whom our remarks may have interested 
I in the matter, to the various English and foreign works on 
torpedo warfare, for fuller and more detailed information. 
! We shall conclude with a few words on mechanical and loco- 
! motive torpedoes. The Eussian drifters in the Baltic are a 
; * It is found by experiment that the regular rolling of the sea will not 
j influence the pendulum, but that it requires the sharp shock of a collision to 
close the circuit. 
