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APPENDIX. 



We have so far considered V, v, as arbitrary quantities ; but it is evident that, with a given 

 vessel, the dimensions and immersion of the wheel and paddles being given, the communication 

 of any proposed velocity to the wheel must determine that of the vessel, and this will evidently 

 depend on the nature and dimensions of the resisting surface she presents to the fluid. The 

 resistance of the vessel may be estimated by that of a plane surface moving through the fluid 

 perpendicularly to itself with the same velocity, and this may appropriately be termed the 



