Modern War Ships.

Professor Hollis lectured on "Modern War Ships" last evening, in the Jefferson Physical Laboratory.

The advisability of building a navy, said Professor Hollis, may seem an unnecessary prelude to a talk on battle ships; but when we consider that England is beginning a war in the Soudan and that Spain is waring in Cuba it is well to consider that nation is most likely to survive which is the best equipped.

The modern battle ship is an evolution from the old Greek galley. Forty years ago we had practically all sailing vessels, manned by sailors; now we have great machines, managed by mechanics. There has been a complete change from heavy wooden frames and weighty constrction to light frames of iron or steel with a thin metal covering.

The first step in building a battle ship is to lay the keel, from keel blocks put down by drawing. The framing is next attached and a double bottom put on. Then the protected deck is added, and the plating put on which completes the preparation for launching. This is done by means of a cradle, and after reaching the water the vessel is docked to receive her equipment of engines, guns, propellors and rudder.

Professor Hollis illustrated the process of construction by stereopticon views and showed pictures of several ships; commenting on their peculiarities of construction.

In conclusion the lecturer spoke of the organization on ship board. This consists of three classes. The marines, a survival of the fighting crew of the old navy; the sailors, the modern fighting crew; and the firemen and mechanics who will probably be the fighters of the future.