THE WAVE AS AN ELEMENT OF RESISTANCE. 



69 



x\ny increase of velocity behind the wave is therefore accompanied by the 



following 



Elements of Increased Resistance. , ■ 



1. Increased Immersion of the bow in the anterior wave. 



2. Inclination of the longitudinal axis of the floating body, so as to change the 



form of the displacing body. 



3. Increased vertical section opposed to resistance == the sin of the inclination. 



4. Increased velocity of the lateral current. 



The following Table, extracted from the experiments of 1835, will serve to 

 shew the rapid increase of resistance which is experienced in approaching the 

 velocity of the wave, which in these cases was 8 miles an hour. 



Example I. 



Example II. 



Velocity in 

 Miles. 



Resistance in 

 Pounds. 



Velocity in 

 Miles. 



Resistance in 

 Pounds. 



6.05 



52.25 



6.05 



95 



6.45 



78.5 



6.45 



100.5 



6.68 



82.5 



6.19 



152.0 



6.49 



111.0 



6.49 



312.0 



6.81 



125.0 



6.81 



386.0 



7.57 



255.0 



6.81 to 7 



392.0 



7.6 to 8 



330.0 



8 miles an hour ^ vel. Wave. 



8 miles an hour ^ Wave's vel. 



The following examples will shew the very slight increase of velocity in the 

 vicinity of the wave, even when the increments of force are considerable. (See 

 Experiments XLIII. and XXXIX.. 1835.) 



Space. 



Time. 



Force. 



Space. 



Time. 



Force. 



Feet. 



100 



Sees. 



10 



lb. 



124.7 



Feet. 



100 



Sees. 



9.5 



lb. 



172.2 



100 



10 



127.5 



100 



9.26 



200 



100 



10 



150.5 



100 



9.25 



212.2 



100 



10 



167.6 



100 



9.0 



227.7 



100 



10 



197.7 



100 



9.0 



239.7 



100 



10 



207.0 









Velocity of the Wave being 100 feet in 8.5 seconds nearly: 



Section VI. — On the Nature of the Diminished Resistance which is experienced at 



Velocities greater than that of the Wave. 



Having now understood the manner in which a floating body moving behind 

 the anterior wave deranges the equilibrium, and alters the form of the fluid, so 

 as to cause a rapid accumulation of the elements of excessive resistance, it will 

 be readily perceived that the annihilation of these elements, which takes place at 

 velocities greater than that of the wave, will prevent the continued increase of the 



