THE INFLUENCE OF NATIONAL POLICIES ON SHIPS' DESIGN. 

 By Captain W. L. Rodgers, U. S. Navy. 



[Read at the twenty-first general meeting of the Society of Naval Architects and Marine Engineers, held in 



New York, December 11 and 12, 1913.] 



It is not unusual for people to assume that a carefully designed, well-built 

 man-of-war is a stock article, as good for one navy looking for ships as for 

 another. 



This not only is not true, but it has never been true at any period. If we go to 

 our histories we shall see a constant progress and development in the types of men- 

 of-war, and that different nations at the same date have had navies composed of 

 ships of types which they have inherited from their past political and their geogra- 

 phic affiliations. 



As an early example we may refer to the campaign of Actium in 31 

 B. C, between the levantine fleet of Antony and Cleopatra and the Roman fleet of 

 Octavius Caesar. The civil wars of the previous half century had permitted the 

 development in the central and western Mediterranean of great numbers of pi- 

 rates who interfered with Roman commerce. About ten years before Actium, 

 Octavius established a strong fleet to put down the pirates and ensure the Roman 

 commerce. This fleet he placed under the command of a very great Admiral, Mar- 

 cus Vipsanius Agrippa, who was also a great naval administrator. For the police 

 of the seas, which was the pressing political need of the day, Agrippa developed a 

 new type (of men-of-war) known as liburnse, specially designed for the pursuit 

 of small groups of piratical craft. These vessels were swift and lightly built; 

 their crews fought with slings, javelins and bows and arrows. In a few years with 

 these ships designed for the purpose, Agrippa suppressed piracy. When the strife 

 between Octavius and Antony broke out, it was with the fleet designed for the po- 

 lice of the seas that Agrippa had to encounter a real battle fleet. 



On the other hand, the levantine fleet was composed of the contingent squad- 

 rons of the vassal kingdoms acknowledging Antony's supremacy. These contin- 

 gent squadrons were the fruit of over three centuries of development of the 

 invention of mechanical artillery. They represented the efforts of wealthy and 

 organized governments to maintain rival great fleets for the furtherance of strictly 

 political objectives. 



Previous to the invention of mechanical artillery in the early part of the fourth 

 century B. C, the chief naval weapon was the ram, and ships were swift and light 

 to maneuver to advantage. The rowers could spurt them to about 7 miles an hour. 

 But the addition of the mechanical artillery to their weapons led to gradual in- 



