CHAPTER IV.
Defensive Torpedo Warfare (_continued_)--Circuit Closers--Firing by Observation--Voltaic Batteries--Electrical Machines--Firing Keys and Shutter Apparatus--Testing Submarine Mines--Clearing a Passage through Torpedo Defences 60
Defensive Torpedo Warfare (_continued_)--Circuit Closers--Firing by Observation--Voltaic Batteries--Electrical Machines--Firing Keys and Shutter Apparatus--Testing Submarine Mines--Clearing a Passage through Torpedo Defences 60