Preparations for a naval war continue to be made with undiminished energy at Portsmouth. Nearly 4,500 men are at present employed in the dockyard alone, and this number is exclusive of seamen riggers and men from the Steam Reserve. The foregoing number of men at work in the yard comprises 1,279 shipwrights, 879 of whom are of the established class, and the remainder are hired hands; 80 established and 13 hired caulkers, 147 established and 90 hired joiners, 11 wheelwrights, 200 established and 89 hired smiths, 76 established and 60 hired millwrights, 59 coppersmiths, 47 at the wood mills, 90 sawyers, 181 established and 764 hired labourers, about 60 locksmiths, braziers, and painters, and in the steam factory department about 750. All this crowd of men are fully employed, and many of them are working extra hours to complete some of the most pressing portions of the work, as in the mast-making department, which is now working up to 8 p.m., to complete the masts and yards for the Black Prince, Glasgow, and Octavia. The smiths' shop, with its 102 fires, seven furnaces, and seven Nasrnyth's hammers ranging from a 10 cwt. to a 5-ton head - the latter having attached to it an hydraulic crane with a 50-ton lift, - is as busily employed throughout as the other departments in providing for the wants of the ships preparing for the pennant. The ten docks possessed by the yard, are all occupied in one way or another, and in the majority of them swarms of workmen may be seen engaged on every part of the vessels, in carrying out the necessary repairs, &c. In No. 1 is the Coquette, 5, screw, now nearly complete for commission. In No. 2 the remains of the Meteor, iron-cased floating battery, are being broken up as rapidly as possible to render the dock available for the general work of the yard. In Nos. 3 and 4 are the Highflyer, 21, screw, and the Rosamond, 6, paddle; the former unopened, but requiring heavy repairs, and the latter partially repaired and destined for a floating steam factory. From both these vessels the men hitherto employed on them have been withdrawn, and placed upon more pressing work. In No. 3 is the Esk, 21, screw, with stem out, and partially stripped of bow planking, disclosing a very rotten and defective state. Her time for being out of the dockyard hands is given for the 9th of May, but at present she has not quite 50 hands upon her. In No. 6 is one of the harbour steamtugs. In Nos. 7 and 10, the double dock, is the Black Prince, the great trouble of the dockyard officials. Internally she is a vast workshop, in which artisans of every kind are busily at work with but little hope of finishing their labours by the time given for her to be out of hand - the 30th of April next. The teak lining forward and aft of her armour plating is being completed, and the scuppers leading to the "main sewer" are being enlarged and increased in number. Another bridge is also being constructed across the quarter-deck. In addition to the construction of the model for her fish-head, and the general fitting of her main and upper decks, an immense deal remains to be yet done - such as the construction of her hammock-nettings, alterations and additions to her head rails, netting, and fitting of her cabins below. In the Black Prince, as in the Warrior, the crew sleep and mess on the main deck, in lieu of the lower deck as in ordinary frigates, owing to the iron ships below the main deck being divided into compartments. These consist of, in the after part of the ship abaft the armour plating, -1st compartment from stern, store-rooms; 2d compartment, the officers' mess-room and cabins, or ward-room; and the 3d compartment, next to the armour plating, containing the clerks' office in the centre, with a mess-room on each side, one for the midshipmen and the other for the engineer officers. The next compartment, inside the armour plating, contains the magazines, store and light rooms, succeeded by five others within the armour plating, containing respectively the engine-room, chain and shot lockers, shell-rooms and coal-rooms, after boiler space, fore boiler space; and, lastly, the fore hold and fore magazine. Forward of the armour plating is the cable tier, prisons, and provision-rooms, the warrant officers' cabins, the sick bay, and lastly, in the bows, warrant officers' store-rooms. Outside the ship the bilge pieces on the bottom are nearly affixed to the angle irons, and the scraping of the ship's bottom has been begun, to prepare it to receive a coating of the patent composition, prepared by the Admiralty chymist, Mr. Hay, with which also the bottom of the Resistance, at Chatham, is ordered to be coated. One serious defect, of an almost if not quite irremediable character, exists in the construction of iron-cased ships as constructed at present, and is fully exemplified in both the Warrior and Black Prince. This evil is the penetration of water between the teak and armour-plates. This water naturally forces for its exit a passage between the joints of the armour plates, and the opinion at present is that nothing can remedy this under the circumstances of tongued and grooved edged plates hung on a ship's sides by through bolts. Caulking is stated to be useless, and that cannot be wondered at considering the slung weight to be dealt with, and the ship's motion at sea. But the effect of the action of the water in the grooves of the plates and upon the iron bolts can only be expected to be such that in four or five years from the time of commission each ship will require replating. In No. 8 dock, the Glasgow, 51, screw, is being caulked and prepared to receive her copper. Her time for being out of the dockyard hands is the 28th proximo. No. 9 dock has been used of late, for breaking up old ships, but it has been cleared during the past week, and yesterday received the Chanticleer, 17, screw, Commander C. Stirling, and is therefore now added to the list available for general service. In the steam-basin are the Prince Regent, 89, screw, complete in machinery; the Octavia, 50, screw, ordered to be finished by the 1st of March; the gunboats Swinger and Savage received their 100-pounder Armstrongs to-day, and were to be ready for sea this evening; the gunboat Jasper, of 89-horse power, being brought forward as quickly as possible by the shipwright and factory departments; the Hazard, with Capt. Cowper Cole's shield model, and the Wallace, steam tender. Alongside the north wall of the basin is the Dart, 5, three-masted screw schooner, nearly complete in rig stores and armament; and the four gunboats, Earnest, Foam, Cracker, and Pheasant, only requiring each their 40-pounder (they have their carriage and equipment on board) to make them ready to proceed to sea as soon as their crews and powder could be sent on board. In the ship basin the Tribune, 28, screw, has her machinery in order, and is being hurried forward in the other parts of her outfit; the Fancy, gunboat, is completing heavy repairs to her hull; the Sultan is fitting for a receiving ship, and the Juno fitting for a police ship. Her upper deck seams have been payed on opposite sides by the patent waterproof glue and ordinary pitch, to test the merits of the former, of which much is expected. The poop of Her Majesty's ship Victory is also to be caulked with it, as are two ships to be named by the Admiralty, one of which will be despatched on service in a hot climate, and the other in a cold one. The Britannia, naval cadet ship, Capt. R. Harris, is to be taken into this basin on the 14th inst. to complete her outfit for Portland. Alongside the shear jetty of the ship basin the Duncan, 101, screw, is carrying on her outfit, to be completed by the 28th inst., and yesterday shipped her Griffiths propeller; while off in the stream, moored in a line with each other, at about a cable's length apart, lie, ready to proceed to sea at an hour's notice, three of the finest 50-gun screw frigates in the world - the Euryalus, Shannon, and Sutlej. In the building slips there is no great bustle, all the labour of the yard being devoted to bringing forward the craft most urgently wanted. In No. 1 slip the Helicon, paddle-wheel despatch vessel of 835 tons and 200-horse power, has her timbers in position, with the exception of a portion of her stern. In No. 2 the Harlequin, 17, screw, 950 tons, 200-horse power [cancelled in 1864], is in frame and nearly ready for planking. ln the next slip the Dryad, frigate, of 51 guns, 3,027 tons, and 600 horse-power, is complete in her framing, getting her deck beams in position &c. The next slip is empty, but is designed for the Kent, iron-plated frigate [cancelled in 1863]. In the last slip stands the Royal Alfred, laid down for a 91, but now converted to a frigate of 50 guns, and to be cased with 4½-inch plates from the manufactory of Messrs. Brown and Co., the Atlas Steel and Iron Works, Sheffield. One peculiarity in these plated frigates will be that they will have a stem falling inboard from the water line, and carry no projecting figurehead. In addition to the number of men we have quoted as being employed in the yard by the Government, there are also a number of others employed by private contractors in the construction of No. 11 dock (to be capable of receiving ships of the Warrior class) and other works. The only part of the yard, however, which is really inactive in the midst of all this bustle is the coaling jetty erected by a contractor at the south end of the yard. This work projects some 60 feet from the dockyard into the harbour for a length of 600 feet and upwards, and its cost for the jetty alone (saying nothing of the expensive hydraulic machinery, not yet erected) was 15,000l. Its professed purpose was to fulfil the duties of a grand embarkation and disembarkation stage for troops from large transports, and to coal two such ships as the Warrior and the Black Prince at one and the same time. Its fulfilled duties have been that a merchant transport discharging troops on one occasion grounded at low water and proved it to be at present totally unsuited for the purposes for which it was constructed. It may be rendered serviceable, and perhaps for the duties for which it was originally intended, but at the present time it is useless. The work consequent on the outfit of the ships and gunboats at Portsmouth is not confined to the dockyard alone, the Royal Clarence Victualling Yard at Gosport and the ordnance and military store department having also their share of the work to carry out.
The steam transport St. Andrew, Capt. Dutton, now embarking materials of war for America at the Royal Arsenal pier, Woolwich, has shipped 300 tons of heavy Armstrong guns, shot and shell, 900 tons of light stores, consisting of cases of small arms, bales of warm clothing, accoutrements, hospital comforts, and other miscellaneous articles, and 85 tons of powder. Notwithstanding her superior cabin accommodation no positive orders had been received up to last night for the embarcation of any passengers.
The hired steamship Brunette yesterday, moored off Woolwich Arsenal, and will take up the berth of the St. Andrew to ship 500 tons of shot, shell, and other stores for Bermuda.
The steam transport Parthenon yesterday commenced receiving about 500 tons of heavy cargo, - namely, shot and shell, for Jamaica.