FIG. 25. THE MAIN PARTS OF A SUBMARINE.
This instrument is formed of a long tube with a hood at the upper end, which is outside of the conning tower, and an elbow at the lower end, inside of the tower. An eye-piece is fixed to the lower end, so that the captain can scan the horizon at all times. How a periscope is made and used will be described in a later chapter.
Courtesy of Scientific American
THE CONNING TOWER (UPPER) AND NAVIGATING COMPARTMENT (LOWER) CONTROLS OF A MODERN SUBMARINE
Just below the eye-piece of the periscope is the underwater steering wheel, and close to and to one side of the latter is the underwater compass. In the more recent submarines a gyroscopic compass[17] is used as well as the regular magnetic compass because the gyroscopic compass is not affected by stray magnetic lines of force. Besides, a gyro compass, as it is called for short, points to the true north instead of to the magnetic north pole, and a true compass is of the greatest importance in guiding the submarine at night or when it is submerged, for it is then as blind as the fish in Mammoth Cave.
Around the inside of the tower near the bridge are placed ports through which the captain makes and takes his observation when the boat is afloat. Within easy reach of his mouth are speaking tubes which lead to the engine, diving, and torpedo compartments. The captain also has at his finger-ends an electric signal system of lights and bells, which he operates by push buttons and switches.
So you see he can get into instant touch with all the vital parts of his boat. He also has full control over the trimming tanks and the storage batteries, both of which I shall tell you about in detail presently.
Right in the line of sight of his eyes is a depth meter by which he can see at a glance at just what depth his craft is moving, and he can also see at what angle[18] the diving rudder, or elevator, as it is called, is set.