Propeller for Steam Ships. 11 



Many novel inventions have of late years, been proposed 

 as a substitute for our pi-esent mode of propulsion. 



The principle upon which many of these are based is the 

 supposed advantage of confining the water that is to be acted on 

 with the object of securing a better hold on the water, and 

 some of these methods have appeared to be at least equal in 

 practical effect to the paddle wheels and screw ; but there is 

 reason to believe that whatever is gained by confining the 

 water is lost by the great lateral pressure and friction of 

 the water in the tubes and confining cylinders, and the 

 amount of propelling force is to be measured, not by the 

 hydraulic pressure, but by the volume and velocity of the 

 water put in motion. 



There seems, therefore, no sound reason why a propelling 

 float of suitable dimensions, acting in deep water, and at 

 right angles to the longitudinal axis of the ship, should not 

 give the greatest available amount of propelling power, in 

 proportion to the steam power employed. 



If such be the fact, all future progress in steam propulsion 

 must depend on the discovery of an effectual method of fea- 

 thering propelling floats in deep water, without loss of power. 



The advantages claimed for this new propeller are — 



1. That it acts wholly under water, and may be placed 



at a considerable depth, where the water has an 

 increased resistance. 



2. There is very little loss of power in feathering the 



floats, or in working the propeller. 



3. It may be connected with the piston rod, without the 



use of the crank. 



4. The action of the floats may be easily reversed, with- 



out stopping the pistons. 



5. With high-pressure steam, and increased speed of 



piston, and length of stroke, this propeller might 

 be worked without gearing of any kind, and is 

 apparently adapted for high rates of velocity. 



6. Its action is more in accordance with that [of the 



natural propellers of birds and fishes than either 

 the paddle wheels or screw. 



7. The machinery necessary for working the propeller 



will be more simple, and much less weighty, and 

 therefore much less expensive, than that hitherto 

 employed in steam navigation. 



