162 Atlantic Steam Navigation. 
miles per hour for the true speed of the ship by steam cy 
The distance from Portsmouth to New York is 3000 miles; # 
supposing the ship to run thirteen miles an hour, she would make 
the passage from port to port in nine and three quarters days. But 
we must not overlook the fact that the resistance of the water 
will increase as the square of the velocity of the ship; and there- 
fore it may happen that the same-power acting against an in- 
creased resistance, will not be found adequate to maintain the full 
speed which the calculation indicates. But I apprehend it cannot 
fall much short in velocity, and therefore cannot much. exceae in 
the time required to perform the voyage. 
Each set of floats is sustained by three radii, fifteen feet in 
length from the centre of the wheel to the periphery. But if we 
count these three radii as one lever of fifteen feet in length, then 
we have, by the combination of thirty one sets of levers, two 
equal to 2324 feet in length, acting horizontally upon the body 
of the ship, without the slightest tendency to throw her from an 
even keel. The danger of the ship’s capsizing, of being taken 
aback, or of being dismasted, is entirely obviated, and the vio- 
lence of the winds can have little other effect than that of om 
turbing the surface upon which she floats. 
P.S. The President, of the same tonnage as the British Queen, 
is now building for the New York line, and will be followed by 
= —— Britain and the United icons 
LETTER I. 
ondon, Sept. 5, 1838. - 
Having shown, in my letter of 31st July, iiint the navigation 
of a ship by steam power is more philosophical than by sails, be- 
cause the power is applied to short levers, acting in a direction op- 
posite to that of the power of wind upon sails, and always in a 
line horizontal to the body of the ship, and that therefore the 
. danger of the ship’s being capsized, or taken aback, or stran 
or dismasted, or strained by perpendicular levers, is entifely obvi- 
ated ; I proveed to suggest a few things relative to the practical 
vents of sailing ships and steam ships. 
_ Notwithstanding all that has been said and written upon the 
impracticability of navigating the Atlantic by steam ships, recent 
experiments have confounded the theoretically Wise, and placed 
the mereneinite which r no assent can shake. Driven 
