Locomotive 
torpedoes, and 
to! o- 
vessels. 
xxxiv. New Zealand Institute. 
pass up the harbour and appear before Port Chalmers in order to 
capture or destroy the shipping there, or he might take up a 
position off the Ocean Beach, from which he could, if not prevented, 
throw shells into Dunedin, and thus enforce submission to a demand 
for a contribution. 
As regards defence against the first mode of attack, the entrance 
to the port being under 600 yards wide, and the conditions being other- 
wise favourable, the channel can easily be barred by submarine mines 
covered by artillery fire from Taiaroa Head. This feature can be 
readily rendered secure against assault, and, within the enclosure so 
formed, guns should be placed in the most suitable positions for com- 
raanding the approach and the entrance. 
or the defence of Dunedin against bombardment from the sea, 
batteries should be established, as has already been proposed, at 
Lawyer's Head and at Forbury Knoll, about 4,000 yards to westward of 
it. Torpedo-vessels might also aid in preventing hostile ships taking 
up a position whence he could throw shells into the city. 
A field force would oppose any attempt of an enemy to land at 
Waikouaiti or other part of the coast outside the harbour in the 
neighbourhood. 
THE BLUFF. 
The importance of the Bluff Harbour (see Plate V.), which, 
though not very capacious, is of sufficient depth and size for large 
ships, is due, not only to its being the first port of entry and the last 
of departure in the south of New Zealand, but also to the circum- 
stance that it is admirably situated as a centre whence vessels of war 
may issue for the prevention of the hostile occupation of adjacent 
harbours, or for general naval action. 
The obvious plan for the defence of this harbour is to occupy 
the peninsula east of the harbour, and on its highest point construct 
a fort which will deny the anchorage to an enemy, and command the 
approaches to it. 
Submarine ground mines may be placed in the channel, which at 
its narrowest part is only 600 yards wide. 
To prevent the landing of a small force at any point to westward 
of the entrance not commanded by the fort, and where he might pos- 
sibly attempt to throw a force on shore, earthworks may be improvised, 
and a field force from Invercargill, eighteen miles distant, and con- 
nected with the Bluff by railway, would co-operate in the defence. 
In reference to other harbours for the defence of which no special 
provision is proposed, I will first briefly refer to locomotive torpedoes 
and torpedo-vessels. 
