is made of thick sheets of steel called armor plate and this covers the ship from her stem to stern-post just above the water line.
The part of a battleship where a shell hitting her would likely do the most damage is at her water-line and if a shell should hit there and explode it might tear out a big hole when she would quickly fill with water and sink. To prevent this from happening a very thick band of steel armor plate is riveted all the way round her at the water-line.
All the machinery and equipment of the ship including her engines, boilers and machinery, the powder magazines and shell rooms, the pas- sageways through which the ammunition is taken, the wireless room, in fact everything except her guns, is in the hold below this strong deck. Of course there must be some openings in this deck but these are protected by gratings of heavy steel, the bars of which set closely enough together to keep fragments of shells from going through should one hit and explode on deck.
On our battleships the main battery is generally made up of four 10 inch, 12 inch or 13 inch