The smooth-bore guns used form a complete range of calibres from the 15-inch to the 6½-inch. The turret-guns, which are exclusively of the 15-inch pattern, are of the Rodman type of construction, of cast-iron, being cast on a core and cooled from the interior. The exterior surface shows no sharp angles and no muzzle-ring, the general shape being that of a bottle with a rounded base. The chamber of the gun is of two types, cylindrical and conical, in accordance with different dates of fabrication. The 11-inch guns are used exclusively for pivot-guns of first and second class corvettes, and it is this calibre that is being converted into 8-inch rifles, the intention being to so transform all of this type. These guns are of the Dahlgren type of construction, being similar in shape to the 15-inch (with the exception of having a swell at the muzzle), but _solid_ cast. These guns all have conical chambers. The 9 and 8 inch and 32-pdr. are broadside-guns, and are similar in construction to the 11-inch. The 24-pdr. and two classes of 12-pdrs. are of bronze, having a conical exterior surface. These guns are used as light upper-deck guns and boat-guns. [Illustration: 12-pdr. Bronze (Smooth-Bore).] [Illustration: 100-pdr. Parrott M. L. R.] [Illustration: 20-pdr. Bronze M. L. R.] [Illustration: 12-pdr. Bronze M. L. R.] _Rifled Guns._ The muzzle-loading rifled guns are of three patterns. 1st. The 8-inch converted. These guns are all converted from the 11-inch smooth-bore on the Palliser system (see page 217), the length of bore being slightly increased by cutting back at the breech. 2d. The Parrott type, a compound gun consisting of a cast-iron body with a coiled wrought-iron hoop over the powder-chamber. These guns were introduced into the service in 1860, contemporaneously with the first development of rifled guns in Europe. As early as 1862, guns of this type with a calibre of eight inches were in active service, being at that time as powerful as any guns in the world. The 8-inch calibre has never been extensively used in the service, and is at present obsolete. 3d. The Dahlgren type of bronze muzzle-loaders. The 20-pdr. gun of this type is similar in shape to the general smooth-bore type, slightly modified. The light calibres are similar to their corresponding smooth-bores. [Illustration: 8-inch Converted M. L. R.] _Breech-Loaders._ [Illustration] [Illustration: 3-inch Boat-Gun (R. B. L.).]