88 
“ It has been objected that, ‘ As the front apparatus is set in 
motion by the resistance to the vessel’s progress, the stern 
screw can have na propelling power whatever.’ Now this, 
you will perceive, assumes entirely the point in dispute, 
instead of attempting to prove it. It is indisputable that the 
action of the water upon the conical screw would cause a large 
amount of force to be given out by the propeller, and the only 
way in which this can be rendered nugatory, is to suppose 
that there would be as much additional resistance generated 
by the flanges of the revolving bow (which is in reality to 
suppose that the mode of displacement is equal to displace- 
ment itself) as would be given out by the stern screw. I 
think the experiments I am now prepared to make, in an 
artificial stream, will shew that no such increase takes place. 
The water in front is pressed very little more forcibly by the 
flanges of the cone than it would be by the cone itself, if the 
flanges were removed, but the water at the stern is pushed 
with considerable force by the screw, and by a force which 
increases with the ship’s velocity. In one of the small models 
now exhibited, the revolving bow, in a moderate stream, gives 
ninety-two revolutions per minute to the propeller. 
“ No one, at this day, will imagine that any power can be 
created ; but a great deal is lost, and perhaps some may be 
saved. The ordinary head of a vessel may be regarded as a 
w’edge employed to split open a channel for her. In her 
voyage, the water is at every moment making an efibrt to 
press the two sides of the wedge together, and yet no attempt 
has been made to economise this constantly-sustained pressure. 
Now, a cone is a wedge in every direction — a circular wedge — 
and by surrounding it with spirals, it will become a revolving 
wedge, the flanges themselves constituting an active part of 
it. I submit that by driving through the water an immovable 
wedge, a large portion of the motive power is wasted ; but by 
employing a revolving bow, that wasted portion may be 
economised. I believe that the result may be thus stated : 
