A.—No. 4,

- • ■ t i) -ml i.tan i • . ii ( w „ 4*Vv- ,* ■ ■■ •■ 'Memorandum by the; Hon. the Defence Minister for Captain Hutton". The defence, in case of a general European war, of the harbours' of the Colony against a class of small but fast and heavily armed ships ifc a consideration worthy of attention. It is not'intended to make any attempts at fortifications to repel the attacks of large iron-clads ; these are not likely to be seen in our waters. The improvements however in modern artillery enable a one-gun vessel to inflict considerable damage, and vessels of the " Alabama " stamp must bo guarded against. ■ ■ Tlie harbour defences of Auckland are obsolete : Captain Huttoji, whose staff service qualifies him for the duty, is therefore required to submit a plan for putting the Port of Auckland in safety from any sudden attack from cruisers' of small tonnage. In making up the report,' due regard must be had to the necessity for combining economy with efficiency. In a general way, Captain Hutton's report should mention the position and armament of each battery he proposes, together ' with the ranges, and the estimated cost per gun, whatever be the principles of defence. Suggestions will also be expected as to the nature of the ordnance he may recommend for import from England, with regard to^ the use of torpedoes, &c. The report will eventually be submitted to a Commission appointed for the purpose. A month's time will no doubt be required by Captain Hutton to complete his report; and his remuneration for this service will be a sum of £30. Auckland, 13th March, 1871. • Donald McLean.

No. 2. Captain Htjtton to the Hon. the Defence Misisteb. Sir,— i..i, ■ : , , . . . Auckland, 3rd April, 1871. I have the honor herewith to forward my .Beport on the Defence of the Harbour of Auckland required of me in your Memorandum of the 13th ultimo. 1 .'• ■ i i ...i- .. - 4 J I have, &c, The Hon. the Defence Minister, Auckland. F. "W". Hutton. . .. , Enclosure in No. 2. Eejoet on the Defence of the Harbour of Auckland. In compliance with my instructions I have not taken into consideration the defence of the harbour against a regular attack by ironclads or by a blockading squadron, but have limited my recommendations to the defences that I consider necessary to repel a sudden attack by one or two small cruisers or privateers, coming to the Colony for the purpose .of plunder only, and not with any idea of taking possession of it. - I have in the first part considered the subject generally, and these remarks will therefore apply to all the ports, of New Zealand. In the second part I have suggested the best way of applying the conclusions, arrived atiin the :first part, to the defence of Auckland. I regret that I have been unable to give, as required, detailed estimates of the various means of defence ; but I apprehend that the cost of the most important items, such as, the self-acting electric torpedo, is'hardly yet known in England. Pabt I.— General Considerations. Defence hy Torpedoes. —Of late years the system of defending ports by means of torpedoes has come info very general favour. It is certain that during the American war the Confederates employed them very successfully, and in the last war between France and Germany they have the credit of entirely paralyzing the action of the: Erench, fleet. . On. this point, however, we are in want of authentic information ; and I am inclined to think that it.will be found that the heavily-armed forts and the shallow bays in whicli they are situated, by preventing the French ships from taking up positions sufficiently near, have had more influence: than torpedoes. . f-. . Different kinds qf'Toi'pedoes.—Tovpe&oes as at present manufactured are of four kinds:—l. The percussion torpedo ; 2. The shore-fired electric torpedo; 3. The self-acting electric torpedo ; and 4. The Harvey torpedo. Submarine, guns and floating torpedoes propelled by mechanical contrivances might also be added to.the list; but, they have not yet been brought to such a state of practical usefulness as to warrant any further reference being made to them in this report.

PAPERS REIITIYE- TO DEFENCE OF THE HARBOURS "'. '■ ' ''OF -NEW' ZEALAND.