^»* of Ships and Vessels, 32S 



creased, and also the resistance of the water on the lower part 

 of the bottom. It therefore appears to me, when a ship, 

 immersed to a certain depth, has not sufficient stabiUty under 

 sail, that the masts should be reduced, in preference to im- 

 mersing it deeper in the water. 



That it is most natural a ship should have masts in propor- 

 tion to the body below the surface, when immersed to what is 

 considered a proper depth, must appear very evident ; and also 

 that, with such masts, she would sail equally well, as with a 

 deeper immersion and proportional addition to the masts. But 

 it must be expected the ship would be more uneasy under the 

 increased masts in bad weather ; and as the masts and rigging 

 may be considered as back sail on a wind, the increased 

 masts and rigging must also add to the impediment of her sail- 

 ing. Consequently, the advantage must evidently appear in 

 favour of the lesser masts and immersion. 



The case of the Essex must appear as strong proof in favour 

 of the principle in sailing off* the wind ; being, no doubt, bal- 

 lasted in proportion to her masts. At the same time it must 

 be allowed no just conclusion could have been derived from a 

 trial of her on a wind ; as on that point, although the sail might 

 be considered in fair proportion to the body immersed, yet, 

 from the body floating high above the surface, the resistance 

 of the wind on it would have been much greater, than with a 

 deeper immersion and masts in proportion. Neither would the 

 immersion have been sufficient to resist the lateral impulse. 



Chapman, in his Treatise on Ship Building, observes that 

 ** to determine the surface proper to be given to the sails from 

 the knowledge which we have of the effect of the wind on 

 planes or sails, with different velocities in different directions, 

 it would be necessary to enter upon long calculations of great 

 difficulty, and yet of little importance. We may compare plans 

 of ships and of their rigging which are tried and known, and 

 nothing will be required further than to, be guided by those 

 ships which have the best proportion of canvass, with respect 

 to the centre of effort of the wind on the sails and the 

 stabihty." 



And Professor Inman, in his general remarks on the con- 

 struction of ships of war, observes that, <' After all the pains 



