Page:Jack Heaton, Wireless Operator (Collins, 1919).djvu/228

 or the sky; but after awhile I got so I could take in whatever there was to see in between times.

Our submarine had two periscopes, one of the older kind that you have to turn around in order to see the whole horizon, and the other, which was the latest style, showed the whole horizon at once with a magnified view of the ship or other vessel in the distance in the center. This scheme was a great invention as it prevented us from being attacked from behind unawares. It was like having a third eye in the back of your head.

Inside the conning tower are also speaking tubes and an electric system of lights and bells worked by pushbuttons and these run into all the compartments; by means of these intelligence transmission systems our captain could get in touch instantly with the chiefs of the crew in the engine, diving, torpedo and wireless rooms.

There are also several instruments in the conning tower and among these is a depth meter, that is, a device that shows just how far below the surface of the water the boat is. An inclinometer which points out the angle at which the diving rudder, or hydroplane is set, and a