Show AID FOR MODERN SUBMARINE periscope enables 0 operator pe to ob serve what Is passi passing n g on surface of water ali above ove him the modern submarine is effective only because those within the lessel essel are able to look oer the surface ol of the sea in all directions exen een though tile the submarine is beneath the surface of the water later the periscope make tills this possible and so it deserves to be called the eye of the submarine the periscope is a straight hollow tube att ib t rises from the steering compart ment of the absel and reaches above az 7 hua aa the submarines eye the mater ater when N hen the submarine is 1 bin ing just beneath the surface As the th periscope is but six inches in diameter and rises but 18 inches abone aboe th water it I 1 is almost invisible the ra c of light enter the opening in th side of 0 the tube at the top and are reflect ec doNn downward downnard Nard to a lens at the bottom which focuses them and gathers th ill ras into an eyepiece through the operator Is enabled to see what i 1 passing on the surface above him th total length of the periscope on the ordinary submarine is 13 about 15 feet american boy |