Linear Method of finding the Stability of Ships. 99 



Although sometimes agitated to a greater extent than at 

 others, the surface of mid-ocean is never free from the action 

 of waves. A recent authority* has declared that were the 

 whole ocean to be still or stagnant for a few days, all life 

 would be destroyed, both in it and upon the earth. The 

 extraordinary jje}'7na7?e??ce of deep ocean- waves, as a con- 

 servator of power, would seem to be specially adapted in 

 accordance with the conditions which this statement sug- 

 gests : the whole surface may in fact be said to constantly 

 rotate in an average orbit. 



The actual velocity of the particles in wave motion being- 

 less than the apparent velocit}'- of the wave, the mechanical 

 effect is the same as if the body of the wave moves actually 

 with a part of the velocity, as it seems to do. Let us take 

 the case of a great storm wave forty feet in height, 600 

 through at the base, and conceive a volume of water 

 contained in the section of such a wave moving with 

 a velocity of six feet per second, or 860 feet per minute. 

 Or consider an ordinary ocean wave sixteen feet in 

 height and 180 feet at the base ; and multiply the 

 power requisite to move a section of this body of water 240 

 feet per minute by a thousand such and we may form an 

 idea of the magnitude of the energy engaged in stirring the 

 waters. These are the giant forces which are perpetually 

 traversing the surface of the ocean. 



i 



Art. XXX. — On a ^Linear Method of finding the 

 Stability of Ships. 



By E. K. HoRNE, Esq. 



[Read by Mr. MacGeoege, on 11th September, 1871.] 



• The reference has been mislaid, but the assertion is that of an eminent 

 Continental natnrahst. 



H 2 



