^4 Mr Why lock on the application of Oars to Steam-Boats, 
The first objection which occurs to the use of wheels for pro- 
pelling the vessel, is, that there is a great waste of power. The 
wheel, at every point of its circumference but one, is either as- 
cending or descending^ Each of the arms has to be immersed 
at a considerable expence of power, and the effect of its applica- 
tion to the water, in this direction, would be, to lift the vessel 
out of the water, as much as to push it forward upon the sur- 
face, were it not that the force necessary to lift another of the 
arms out of the water, is equal to that which is required to im- 
merse the former. In other words, the tendency which the de- 
scending arm has to elevate the vessel, is counteracted by the 
operation of the ascending . arm, which tends to depress it. In 
short, the space in which the revolution of the wheel is of any 
use in forwarding the vessel, is very small. One-fourth of the 
power, steadily applied in a horizontal direction, would produce 
greater effects. 
The next disadvantage attending the use of wheels is, that the 
force is applied to the water too close to the sides qftht vessel. 
It is true, that this is an objection common to all the different 
methods yet put in practice ; but in the case of wheels, especial- 
ly as they are generally placed nearly as far forward as the how 
of the vessel, the effect is to bring a current against the head of 
the vessel, which impedes its progress, and occasions an incalcu- 
lable waste of power. 
I am aware, that many plans may be, and have been resorted 
to, in order to obviate the first of these objections, and to sub- 
stitute a direct instead of a circular motion. One of these is ve- 
ry ingenious. It consists of a flat chain passing over two wheels ; 
and upon this chain are raised small boards standing on edge. 
As the chain passes in one direction, the boards are immersed in 
the water, and return in the opposite direction out of the water ; 
the two wheels around which they pass being partially underwater. 
The whole of the impulse given by these boards from the lower 
part of one wheel t(Nhe lower part of the other, is direct and 
effectual. Such a plan, of course, is only applicable to smooth 
water, because the force of waves would destroy any slight ap- 
paratus before it had been long in motion. It is of far more conse- 
quence to discover a method by which the sea could be naviga- 
