336 On the Forces Construction, Sec. 



other particulars, for, on mentioning it to some of the knowing 

 ones, in London, they ridiculed the idea, as altogether fabulous, 

 making me ashamed of my credulity; yet I see no impossibi- 

 lity in the story. 



J. H. 

 Stqfoj'd-place, Pimlico. 



Observations on the Relations which exist between the Force, 

 Construction, and Sailing Qualities of Ships of the Line, 



[Continued from p. 233 of the Quar. Jour., Part II., for 1829.] 



As the comparative statements given in Tables I. and II. ex- 

 hibit themselves suiFiciently to the eye of the scientific con- 

 structor, we shall abstain from entering into any thing like 

 an amplification of their contents; but in deriving Table III. 

 from Table II. we must remark, that perhaps its most import- 

 ant result is the developement of the effects of large and 

 small dimensions^ on a ship of the line of a given force. It 

 will be perceived, that in the 80-gun ship of Chapman, 

 although its hull is less in weight than the hull of the French 

 80-gun ship by 182 tons, and carries 193 tons less ballast, it 

 can only get the midship lower port 5.03 feet above the plane 

 of floatation, with an English armament and equipment 

 amounting to 1891 tons. On the other hand, the 110-gun ship 

 of Chapman is a palpable instance of the advantageous opera- 

 tion of superior dimensions, together with a comparatively light 

 hull : with a real tonnage, equal to that required even by the 

 English 120-gun ship, it will carry the midship lower port 2.13 

 feet higher out of the water than the latter. The French 120 

 shows a similar advantage over the English 120 from similar 

 causes ; but even allowing it to have a hull of the same weight 

 as that of the latter, and thus requiring an equal displacement 

 with an English armament and equipment, it will carry the 

 lower midship port 6.44 feet above the water, or 1.78 feet more 

 than the English ship. 



The English 84-gun ship, which is the same as the French 

 80*, is illustrative of the pernicious effects of increasing the 



* Tlie four additional guns are mounted in the captain's cabin, in which two 

 ports on each side were generally left without guns by the French until lately. 



