Five years later this type was improved upon in the _Gustave Zédé_, the largest submarine ever yet designed. This boat, built of phosphor-bronze, with a single screw, measures 131 feet in length and has a displacement of 266 tons; she can contain a crew of nine officers and men, carries three torpedoes--though with one torpedo tube instead of two--has a lightly armoured conning-tower, and is said to give a surface speed of thirteen knots and to make eight knots when submerged. At a trial of her powers made in the presence of M. Lockroy, Minister of Marine, she affixed an unloaded torpedo to the battleship _Magenta_ and got away unobserved. The whole performance of the boat on that occasion was declared to be most successful. But its cost proved excessive considering the small radius of action obtainable, and a smaller vessel of the same type, the _Morse_ (118 × 9 feet), is now the official size for that particular class. In 1896 a competition was held and won by the submersible _Narval_ of M. Laubeuf, a craft shaped much like the ordinary torpedo-boat. On the surface or awash the _Narval_ works by means of a Brulé engine burning oil fuel to heat its boilers; but when submerged for attack with funnel shut down is driven by electric accumulators. She displaces 100 odd tons and is provided with four Dzewiecki torpedo tubes. Her radius of action, steaming awash, is calculated at some 250 miles, or seventy miles when proceeding under water at five knots an hour. This is the parent of another class of boats designed for offensive tactics, while the _Morse_ type is adapted chiefly for coast and harbour defence. The French navy includes altogether thirty submarine craft, though several of these are only projected at present, and none have yet been put to the practical tests of actual warfare--the torpedoes used in experimenting being, of course, blank. Meanwhile in America experiments have also been proceeding since 1887, when Mr. Holland of New York produced the vessel that bears his name. This, considerably modified, has now been adopted as model by our Navy Department, which is building some half-dozen on very similar lines. Though it is not easy to get any definite particulars concerning French submarines Americans are less reticent, and we have graphic accounts of the _Holland_ and her offspring from those who have visited her.