the observation, I think the design which is shown for the aviary in the Regent's Park, although exceedingly elegant in appearance, yet will not succeed for keeping the birds. It is too exposed and open to the north and east to afford any moderate degree of shelter to the birds during winter, and 1 fear many will thus perish. My friend, Mr. Maliphant, architect, in Blenheim-street, has been so kind as to embody my ideas in a design for an aviary, which would, I think, combine all the advantages of shelter and ornament. The front and roof are proposed to be of glass. The centre-part and two wings may be either covered in with glass or patent zinc. A walk may be made within the glass, and outside the wire, as it is proposed to leave a space of five feet between the glass in front and the wire, which would afford room for a paved walk, and a bed for exotic plants; thus combining the beauties of the aviary and the conservatory. It would be advisable to have the wire at the roof within two or three inches of the glass. The same plan would do exceedingly well for a common aviary, in which case wire would be substituted for the glass; and the rooms at each end would be useful to contain delicate birds during the winter months. A. Observations on the Force of our Ships of War. DURING the last few years, naval matters have been gradually coming before the public eye. Open and free discussion has,. at last, made its appearance, and, as usual, has produced vast benefit in dispelling the mystery and darkness in which the construction, equipment, and economy of our naval force were formerly concealed. It is a singular fact, that a Frenchman should have been the first to have deemed our naval establishment worthy of being described and descanted on; but it is no less true, that we owe to a foreigner almost every information we possess on the subject, as well as the attention he has excited by * Baron Charles Dupin-Force Navale de la Grande Bretagne. his writings. That attention has been wonderfully increased; and we now see this once neglected but most important national topic introduced in almost every scientific or literary publication of eminence of the day; and even periodical works expressly devoted to its consideration, have been published. It is true, indeed, that much erroneous argument, and, consequently, many false conclusions have proceeded from those who are unacquainted with naval philosophy; but even these have been of service, for the detection and exposure of error is as important as the developement of truth. The accession of His Royal Highness the Duke of Clarence to the office of Lord High Admiral has given a fresh impulse to the desire of improvement; and it is said to be in contemplation to make some very important innovations in the armament of our floating citadels; it is, therefore, solely with a wish to aid the intentions of His Royal Highness, that we intend briefly to examine the principles to which such alterations. should be referred, and to point out how far we are justified in proposing an adoption of them. The first element to be considered, in a ship of war, is, necessarily, its force; and this consists in its artillery; but there are two ways in which this force can be modified, viz.1st. By the quantity of guns mounted. 2dly. By the quality or calibre of the ordnance. If we merely estimated the force of a ship of war by the number of its guns, we might be led into very great error. The famous Harry Grace de Dieu, built in 1515, was mounted with 122 pieces of ordnance*, a number exceeding even that with which our present first rates are established, but not more than thirteen of these were of the calibre of nine pounds, and upwards. The calibre of a piece of artillery gives us a definite idea of its individual power; but this term alone does not furnish us with a correct notion of a vessel's force beyond that of carrying "heavy or light metal." It becomes necessary, therefore, that both the number and calibre of guns must be expressed, to give us a precise description of the fighting power of a ship. * Charnock's Hist. of Marine Arch. vol. ii. p. 44. In the earlier periods of the application of ordnance to naval warfare, it was usual to carry, not only various calibres on board the same ship, but even to have two or three different natures on the same deck. Much inconvenience and confusion must have unavoidably arisen on this account; but we find that it was not until the latter part of the reign of Charles I. that any attempts were made to remedy the serious evils inherent in such a disregard of system. The first regular establishment of guns for the various classes of ships of the royal navy is, we believe, that given by Derrick, in his Memoirs, and was made in the year 1677. We find in it an uniformity of calibre established for each respective deck; for instance, the lower deck of a three-decked ship of 100 guns was armed entirely with 42 pounders, or (as they were then called) cannon of 7*; the middle deck with 18-pounders, or culverins; and the upper deck with 6-pounders, or sakers. As may be naturally supposed, repeated attempts have been made to increase the force of our ships of war; not only by increasing the number, but also by increasing the calibre, of their ordnance; but the former alternative has, from the difficulties and expense attending it, (by requiring much larger ships,) been comparatively little resorted to; indeed, we find that our present largest first rates carry only twenty guns more than the first rates in 1677; and our largest two-decked ships of the line mount only fourteen more than the two-deckers of the same period. Hence it has been principally in the general increase of calibre of naval ordnance that the present superior force of our floating batteries consists. In treating of cannon with relation to the qualities and capabilities required in them, as forming the armament of a ship, it will appear, on a due consideration, that there are two principal objects which should be attended to in the construction of a piece of sea-service ordnance, viz., facility of its service in time of action, and the influence which the guns possess over the sailing qualities of the ship; both these desiderata are dependent on the weight of the gun. This element not only governs the celerity of its service, but also has a great That is, cannon of seven inches, or whose bore was seven inches in diameter. influence on the displacement and stability of the vessel; it is chiefly on the latter account that in ships of two or more decks, it becomes necessary to diminish successively the weights; and, according to the common constitution of artillery, the calibres in the upper tiers. Since, therefore, it appears that the guns of the greatest weight should be placed on the lowest battery, it will be important to see how far experience has determined this maximum *, which, of course, must, above all other considerations, depend on the power and ease of management in time of action. Manual exertion is confined within comparatively narrow limits; but it is possible to construct a vessel that should carry much heavier ordnance than the heaviest now used. A mass of about 80 cwt. seems, from experience, to be the maximum of weight that can be allowed without losing the requisite celerity in the service of the guns. This we ascertain, not from our own practice, but from that of a foreign nation. The weight of a French 36-pounder and carriage is 83 cwt. †; that of our highest calibre of sea service long-gun and its carriage is only 64 cwt. we see, therefore, that the French retain, as manageable, a weight exceeding ours by 183 cwt., or nearly one ton. Admitting, however, that our 32-pounder is equivalent in force to the French 36-pounder, and is otherwise as good a gun, it would have the advantage in a long action, since it could be served with much less fatigue and with fewer hands. This is certainly an important consideration; but the same recommendation, in a considerable degree, will be found to have been attached to a higher calibre of English ordnance now discarded from the naval service, excepting in the form of car * This quantity is much greater in the sea service, than in the land service, on account of the loco-motion which naval ordnance possesses in common with the ship on board which it is mounted. Garrison ordnance, however, from being stationary, is as heavy as that of the sea service; and, indeed, is generally, in the British service, supplied from it. + The weight of the French 36-pounder used on the lower decks of their ships of the line, is nearly 71 cwt., and the carriage weighs 11 cwt., making together 83 cwt. The English 32-pounder gun of 9 feet long, weighs 56 cwt., and its carriage 84 cwt., making together 64 cwt. ronades. The 42-pounder gun, until the year 1793, formed the armament of the lower decks of all our first rates, and weighed 63 or 65 cwt.; so that even this heaviest of English naval ordnance, which was dispensed with on account of its unmanageable weight, was at least one-third of a ton lighter than the truly powerful gun which still forms the principal arm of the line-of-battle ships of the French navy, and the weight of which has very recently been adopted by an author* of great merit, as that which is sufficiently manageable. We now proceed to make a few remarks on the calibres of ordnance used on board ship. The celebrated Robins, in a tract, first printed in 1747, entitled "A Proposal for increasing the Strength of the British Navy," fully points out the great augmentation of force to be derived from using higher calibres; and Muller, in his Treatise of Artillery, in 1768, makes a similar proposition. The fact is, that the larger calibres possess the great advantage of making greater breaches in an enemy's hull; their superiority of mass produces a greater momentum with a given velocity, and their ranges are greater even with a less proportional weight of powder. The calibres of our guns should never be much less than those used on board the ships of other nations; they may be as much greater as possible. Experience has shown how much our 18-pounder gun, the common armament of our most numerous class of frigates, compromised their safety, when opposed to the 24-pounder of the American frigates, in the last war. : The Portuguese still use their 48-pounder, equivalent to 45.79 lbs. English calibre, for their heaviest ship gun, and the Dutch their 32-pounder, equivalent to the calibre of 34.54 lbs. avoirdupois the Russians, Swedes, and Spaniards, use their several 36-pounders, respectively, equal to the calibres of 31.95, 33.73, and 34.42 lbs. avoirdupois. All these guns, except the Russian, are, therefore, superior to our heaviest calibre, the 32-pounder. But this last gun, which forms the arm of the lower decks of all our ships of the line, stands in a greater ratio of inferiority with the French 36-pounder, than even the * M. Paixhans, Nouvelle Force Maritime, 1820. |