Should this undertaking be accomplished it will be a crowning achievement in electrical science. CHAPTER XII WONDERFUL WARSHIPS Dimensions, Displacements, Cost and Description of Battleships-- Capacity and Speed--Preparing for the Future. All modern battleships are of steel construction. The basis of all protection on these vessels is the protective deck, which is also common to the armored cruiser and many varieties of gunboats. This deck is of heavy steel covering the whole of the vessel a little above the water-line in the centre; it slopes down from the centre until it meets the sides of the vessel about three feet below the water; it extends the entire length of the ship and is firmly secured at the ends to the heavy stem and stern posts. Underneath this deck are the essentials of the vessel, the boilers and machinery, the magazines and shell rooms, the ammunition cells and all the explosive paraphernalia which must be vigilantly safe-guarded against the attacks of the enemy. Every precaution is taken to insure safety. All openings in the protective deck above are covered with heavy steel gratings to prevent fragments of shell or other combustible substances from getting through to the magazine or powder cells. The heaviest armor is usually placed at the water line because it is this part of the ship which is the most vulnerable and open to attack and where a shell or projectile would do the most harm. If a hole were torn in the side at this place the vessel would quickly take in water and sink. On this account the armor is made thick and is known as the water-line belt. At the point where the protective deck and the ship's side meet, there is a projection or ledge on which this armor belt rests. Thus it goes down about three feet below the water and it extends to the same distance above. The barbettes, that is, the parapets supporting the gun turrets, are one forward and one aft. They rest upon the protective deck at the bottom and extend up about four feet above the upper deck. At the top of the barbettes, revolving on rollers, are the turrets, sometimes called the hoods, containing the guns and the leading mechanism and all of the machinery in connection with the same. The turret ammunition hoists lead up from the magazine below, delivering the charges and projectiles for the guns at the very breach so that they can be loaded immediately.