Plate II shows a midship section of a battle-ship of the Indiana class: such a section as would be obtained by cutting the ship in the middle of its length by a vertical thwartship plane. This exhibits the general method of construction of a modern war vessel. The names of the various parts will be found on the drawing and in the glossary of the terms. An examination of this plate will show the difference in shape of material used in iron or steel vessels; and in those constructed of wood.

The keel (1) consists of two flat plates arranged as shown, the pieces going to make up its length being joined by straps of metal. The garboard strakes (2) fit in under the outer edge of the outer keel plate on each side.

The vertical keel (3) rests on, and is secured to, the flat keel as shown. The keelson plate (4) is placed on top of the vertical keel. The flat keel plates are lapped on, and secured to, the stem which consists of a casting of the desired shape of the bow. Aft, they are similarly secured to the stern-post, which is also a casting of the desired shape and size.

There are no dead-woods. The breast and stern hooks consist of angle-irons secured to the inside of the frames with horizontal thwartship plates secured to them.

The frames are made up, as shown, of the outer or main frame (5), inner or reverse frame (6), and bracket plates( 7). These frames are angle-irons of the required size, the cross section of which forms a Z. In the extremities of large vessels and, throughout in small vessels, these bracket-plates are replaced by vertical plates of the required length and depth called floor plates.

The beams (8) have arms at their ends instead of knees, by which they are secured to the frames.

Below the protective deck the ship is divided, horizontally, by perfectly flat decks called platforms, most of which are made water-tight. The vertical subdivisions are made by bulkheads.

By careful study of Plate 2 and Plates 81 and 82 a very good idea can be obtained of the construction of a modern war vessel, together with the internal subdivisions and arrangements.

GLOSSARY.

Armor. Extra thick plates placed around the vital parts of a vessel to prevent the entrance of projectiles.

Armor-shelf. The horizontal shelf upon which the armor rests.

Bridges. The forward bridge, the after bridge, the upper bridge, the lower bridge, according to situation. A connecting gangway between the forward and after bridges, or between the bridge and forecastle or poop deck, is called the fore and aft bridge.

Conning tower. An armored pilot house.

Decks. In a modern war vessel the decks are named as follows::Main deck. The highest complete deck extending from stem to stern. Forecastle deck. A partial deck, above the main deck, forward. Poop deck. A partial deck above the main deck at the stern. Upper deck. A partial deck above the main deck, amidships; when the space under this deck is not enclosed it is called a bridge deck. Gun deck. A complete deck between the main deck and the berth deck on which guns are carried. If there are two such decks they are called gun deck and lower deck respectively.

Berth deck. The first deck below the main deck used primarily for berthing purposes and on which no guns except light rapid-fire guns are carried. Orlop deck. A partial deck between the berth deck and protective deck or water-tight deck.

Protective deck. A steel deck of extra strength and thickness designed for protective purposes. It is divided into middle protective deck, and forward (or after) protective deck.

Water-tight deck. A deck worked in the same manner as the protective deck but of much lighter material, serving only to keep water from getting below.

Splinter deck. A deck worked immediately under the protective deck for protective purposes.

Deck-lights. Small openings to the deck for the admission of light only. Deck space. Space between decks; this space takes the name of the deck above which it is located.

Double bottom. The space between the inner and outer bottoms. In the merchant service this is often called the water bottom

Inner bottom. The inner surface of the double bottom.

Freeing ports. Large openings in the bulwarks for permitting the escape of

water.

Man-hole. A small opening just large enough to permit the passage of a man.
Platforms. Partial, flat decks located below the protective deck. Where there
are two they are called, upper platform and lower platform.
Strake. Applies to layers of plating.

Torpedo port. Opening in the ship's side for the service of torpedo tubes.
Vertical keel. The vertical plate placed on the inside of the flat keel.
Water-tight bulkheads. The internal vertical partitions of a modern vessel

composed of plates and made water-tight. They are designated as follows: Transverse bulkheads. Thwartship partitions placed as required. The one farthest forward is made specially strong and called the collision bulkhead, Splinter or Screen bulkheads. Thwartship partitions worked between the guns on battery decks.

Longitudinal bulkheads. Fore and aft partitions called middle line or wing bulkheads, according as they are placed in the middle of the vessel or out toward the sides.

Wood flat. The wood planking in metal ships.