162 Atlantic Steam Navigation. 



miles per hour for the true speed of the ship by steam power. 

 The distance from Portsmouth to New York is 3000 miles ; and 

 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 exceed 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 232J 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 dis- 

 turbing the surface upon which she floats. 



P. S. The President, of the same tonnage as the British Q.ueen, 

 is now building for the New York line, and will be followed by 

 the Great Britain and the United States. 



LETTER II. 



London, Sept. 5, 1838. 



Having shown, in my letter of 31st July, that 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 stranded, 

 or dismasted, or strained by perpendicular levers, is entirely obvi- 

 ated ; I proceed to suggest a few things relative to the practical 

 results 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 affair upon a footing which no assaults can shake. Driven 



