fire of the fuse and sudden explosion while drilling out or putting in an adjacent shot, through the smouldering fuse suddenly completing the work for which it was intended. One difficulty would be experienced at first in insulating the copper wire with a material that would withstand the heavy blows generally administered in tamping, but when charges of lithofracteur, dynamite, or nitro-glycerine are used in the same places, this difficulty would be obviated by the use of water, mud, or soft material for tamping; and especially in those instances where simultaneous firing is required, the moment of explosion and the number of charges to be dealt with is so completely under control, that I am surprised so little has been done as yet in the more frequent use of electricity for this purpose.

But passing to a more serious consideration of this subject—the firing of torpedoes—I trust I may be excused if I bring before the members of this Institute the extreme and increasing interest taken in this weapon at home and the enormous strides which are being taken, first to bring this arm into use for the defence of ports and the attack upon ships, and secondly to guard, as far as possible, against the disastrous consequences of a successful attack with this weapon. And when we think of the fearful effects caused by the explosion of a well-charged torpedo when placed in its most favourable position for damaging a vessel, and take cognizance of the wonderful powers and varied character of the respective torpedoes, each fraught with the same object, it should do more than interest us, and cause us to enquire in what way these weapons may be of service in the defence of our ports, and whether we have to deal with the Whitehead torpedo, with its complicated and secret machinery, with its evolutions so wonderful that Lord Salisbury lately remarked at a public meeting “that it could do almost anything but talk,”—the Harvey torpedo, which may be towed parallel to the towing vessel and at a long distance from her, and thus be brought to bear in a speedy manner upon the eneemy—or the still more deadly, because hidden, torpedo, moored in the track of ships and ready to be fired by the electric wire, it behoves us to examine and, as far as possible, decide in what way we could be guarded from the attack of armed cruisers, who having levelled black mail upon us, would probably return again at another convenient season. With this object I have brought before you the points which I consider should be guarded and the means of so doing, and I may add that when we see the neighbouring colonies taking this matter in hand with the same object, I think we should be up and doing while there is time and not be in the sorrowful position when too late of knowing that

“Of all the sad thoughts of tongue or pen
The saddest are those, it might have been.”

Owing to the many entrances to our spacious harbour, it becomes a

serious consideration to guard each place, as beyond the ordinary route through the Rangitoto channel we have the eastern passage on both sides of Moto Ihi, the Waiheke Channel and the sand-spit, but the whole of these converge to a point between Brown Island and Rangitoto, thus practically reducing the points to be guarded to two, and these I will deal with separately. Outside of a line drawn from the reef to the mainland no point can be obtained by which the elevation of a gun could accurately be brought to bear upon Auckland, but inside that line several points come in to view which would prove of value for that purpose, though distant from the city, notably the new hospital, All Saints Church, and Parnell, therefore our first defence must be outside this line, and that will commence from the reef. Here the safe working channel does not exceed three-quarters of a mile, and at this place I would place the first line of torpedoes, inside of which I would have a second, third, and fourth line decreasing in number and coming to an apex, all being connected with the station by insulated wire in the way I will now describe. The safe working channel being about 1,500 yards wide, I would place say 14 torpedoes in the first line, 12 in the second, 8 in the third, and 5 in the fourth, the electric connections being carried to a high station, for instance, the North Head, which is admirably suited for the purpose. If this station was decided upon it would be the only one required for the defence of both entrances, as I will show presently.

On the high cliffs approaching the lake, which reach an elevation of sixty or seventy feet, will be required an observing station with one operator to give the signal to the main station at the North Head, by electric alarum, as to the enemy's approaching the first line of defence, and the same with respect to the second and third. From the main station it would be seen by the use of a theodolite or cross-wired telescope (the position of the torpedoes being accurately known) whether the enemy was sufficiently in position for the firing of the nearest torpedo, if not she would be permitted to come towards the second line, and presuming she had gone midwaybetween the intervals in the first line she would now be approaching exactly to one in the second line, and on the signal being given from the observing station that she was already on that line, and its being seen from the main station that she was over or close to the position of the torpedo, it would simply require the depressing of the electric key to insure the discharge of the torpedo and probable ruin of the vessel.

With respect to the defence of the Eastern passage, I wish to draw attention to the narrowing of the Koreho Channel about 1.½ miles N.E. of the Bean Rocks, or nearly midway between that spot and Brown Island, and also that in the centre of this channel is a very shallow bank of only

1.¾ fathoms at low tide, while projecting from Rangitoto is a bank with only 2.½ fathoms, giving only 1,400 yards of channel to the bank on the south side, while midway is the shallow bank about 400 yards long, thus reducing the distance to be defended to less than 1,000 yards. It will thus be seen that fewer torpedoes will be required to defend this passage, and the North Head would be directly at right angles to it, thus placing it very favourably for direct observation, while the highland to the west of the Tamaki Heads would prove a favourable position for observation from whence to signal, either by flags, lights or telegraph, the approach of the enemy to the first line of the defence. I would pay especial attention to this passage, as I think it very likely an enemy would choose that, anticipating that the most used channel would be the best guarded. And it must be borne in mind that the days for attack by sailing craft are past, and that, if Auckland was attacked, it would be by several steamers and not one only, as no enemy would do so hazardous a thing as to send in an unpiloted and unattended steamer, as the slightest mishap to vessel or machinery would at such a time place her at the mercy of those she came to molest; nor is it likely that small, light draught cruisers would be chosen for the work, as in the South Pacific there are no naval stations where the attacking squadron would be safe from the British navy then on the station, or where they could provision, coal, or dock, therefore large vessels alone would be enabled to attempt the work, and again a light draught vessel would be unable to carry an armament sufficiently powerful to do any damage at long range.

With respect to the distance of Auckland from the respective outer lines of proposed defence, I find from the Admiralty Chart that the centre of the first line in Rangitoto Channel is 200 yards less than five miles, but this would be reduced to 4.⅝ miles should the vessel stand well in to the bank, still keeping outside the line; this is measured to the lower part of Queen Street, but by his standing in so close it would preclude him from seeing any portion of Auckland district unless from his mast-head, and then the only places which he could observe would be Mount Eden, Mount Hobson, and perhaps one or two other points of the high land, and from this position I do not think we have anything to fear from shot or shell falling into the city, as irrespective of the distance he has no point on which to concentrate his fire, and certainly none on which to observe the effect of his work. But from the Koreho Channel the position is altered, as here he has full view of the town, which he could absolutely rake provided he had artillery which would carry far enough; but the distance from this point to the lower part of Queen Street is five miles and 300 yards, and here again must be borne strongly in mind the fact that guns heavy enough to throw shell

such a distance can only be borne on large vessels, and the draught of these would not permit of such a ship lying at anchor in 3.½ fathoms of water at low tide, as the risk of grounding at low water, which she would inevitably do, would be too great, as any injury to her screw or rudder would almost certainly prove fatal to her enterprise. It will be seen from the chart that I have taken this necessity in view all through, and thus only protected the channel, leaving the banks unguarded; if, however, a light draught steamer was to accompany the attacking fleet, she might be sent forward to try and get within range of the city, and this she could only do by running the gauntlet of the defences, or getting over the banks north and south of the Koreho Channel; to prevent this, a few torpedoes could be placed on the banks, and with a few judiciously placed dummies, which being seen would make her cautious how she essayed the attempt, would, I think, be sufficient. One more point and I have finished with this part of my paper. The electrical station which I propose at the North Head would be two miles and 700 yards distant from the outer line of the eastern defence, and 2.⅞ miles from that in Rangitoto Channel, and from this point a gun battery would be well within range to prevent a small steamer running in, and also to guard the electric wires from any attempt at dragging and grappling them. It might be worthy of consideration as to the advisability of laying a few electric-attached torpedoes, with circuit-closing attachments, by which any vessel coming in would, on contact, close the circuit herself and thus discharge the torpedo directly under her; two of these circuit-closers might be attached, floating just beneath the water at a certain distance on either side and above the torpedo; any ship then touching either would be within striking distance of the charge, and in time of peace the connections of the battery would be broken, or if only a weak current was permitted to flow, the addition of a light, deflecting galvanometer would give notice of a passing vessel during the night.

But the laying these torpedoes as I have proposed is not by any means all that is necessary. What we require first is a volunteer company, to be especially trained to the work. It would not require many men, but they must be of undoubted courage and intelligence; and I think there would be no difficulty in forming such a company of, say, thirty men, which might be attached to the artillery or naval force, but preferably remain intact. They would require to master the knowledge of the different torpedoes and the means of firing them; then, with the addition of a few Harvey, two or three Whitehead, and some spar torpedoes, I think the port might be made thoroughly impregnable. The use of the small steam launch, now so seldom required, might be given to them occasionally, and they would thus make themselves thoroughly acquainted with the positions they had to defend;

and to effectually prepare for the defence, it would only necessitate fixing the anchors or blocks of stone to hold the torpedoes in place, together with a rope reeved through the ring and buoyed, so that in time of danger the torpedo could be attached to its electrical connections, and hauled down into its place.

There are many details which it would be the duty of the company to learn and understand so thoroughly that when needed everything would be in position and free from any fatal hurry. One actual necessity for the completion of this scheme would be, in times of actual danger, the closing of the port between sunset and sunrise, and the establishment of a pilot force for reconnaissance before permitting any vessel to enter. Without this the whole plan would be valueless. The closing the Bean Rock lighthouse, and removal of buoys and beacons, would also be advisable.

With respect to the sunken torpedoes, I would have them made in the simplest manner, very similar but much smaller than the iron buoys which mark our coast. The connections would require to be severely tested, and the charge would be of dynamite or lithofracteur, fired by fulminate of mercury. If of dynamite, which would be preferable on account of less danger to the charge from leakage, the cartridge would not need to be more than 50lbs., equal to an explosive force of 300lbs. of powder. I think it would be found more economical to increase the number of torpedoes than the weight of the charges. Dynamite is a material of commerce now, and generally obtainable; but if in case of danger it was found necessary to make it, we have material in the city to make several hundred pounds of nitro-glycerine, and the men to undertake its manufacture, while infusorial earth is obtainable at the distance of a few miles from the city. Fulminate of mercury also could be prepared in a few hours when required.

I have thus shown that the work of defending our port can be done at any moment, and if it were carried out as I have suggested by a volunteer torpedo company it would be but a small expense to the Government, and could go on in fine weather and at leisure; and when it was known that defence became a necessity the completion of the work could be carried out systematically and orderly long before there was any actual need of it, as with the telegraphic communication with Europe we should be in possession of the news in a few hours, while several weeks would elapse before an enemy could put in an appearance. I have now completed my remarks upon the subject of defence by torpedoes, but with your permission will say a few words upon the probability of landing being effected.

I do not anticipate any danger from this, as it is unlikely so large a squadron would be despatched to such a distance as to enable them to land a sufficient body of men to prove a source of real danger; but, presuming