as practicable with other means of defence. At or near most of the places last named, field forces of riflemen and field guns would also be available for their protection. Before referring to the plans for the security of the principal places of New Zealand, I will make some general remarks respecting guns and submarine mines, and the mode in which they should be applied. Remarks respecting guns, submarine mines, &c. I wish for a moment to draw your attention to the enormous increase which has taken place during the last twenty-five or thirty years in the size and power of guns. When I first had to deal with fortification works, in 1852, and for several years afterwards, the most powerful piece of artillery was the smooth-bore 68-pounder. Now we have guns of 100 tons weight. In the large diagram before you, you see the 68-pounder shown inside the 100-ton muzzle-loading gun. The length of the 68-pounder is 10ft., whilst that of the 100-ton gun is 32ft. 6in. Here is a model of the 68lb. shot and of the cartridge for that gun; there is a model of the missile and charge for the 100-ton gun. The missile is 2,000lb. in weight, the charge is 550lb. of gunpowder, i.e., five barrels and a half, and the two together measure about 10ft. in length! I may mention that some of these 100-ton guns are actually mounted at Gibraltar and Malta. In the more recent manufacture of powerful guns, however, breech-loading has been adopted, and the calibre reduced, whilst the length of the piece is increased, in order to provide the required capacity for the expansion of the gases of the very large charges used, which consist of very slow-burning powder. There are guns now in existence on this principle of 70 to 75 tons weight, which are superior in power to the 100-ton gun to which I have just referred. It is scarcely necessary for me to say that I do not suggest that such enormous guns as those to which I have just referred shall be employed in the defences of New Zealand. Ships carrying armour of a thickness which these pieces are intended to pierce are not likely to find their way to Australasia. The Government of New Zealand, in 1878, acting on the advice of a Committee assembled in London to consider questions relating to the defences of the colonies, procured from England a number of 7-inch and 64-pounder muzzle-loading rifled guns. These will form a considerable portion of the armament of the proposed works. The 64-pounder is not an armour-piercing piece, though effective against vessels unprotected with iron plating; but the 7-inch gun is calculated to pierce 7 inches of iron at 1,000 yards, and 6 inches at