On Ship-building. 167 



author has followed the steps of Chapman, that ingenious man, though 

 possessing much less theoretical skill than Euler, Bernouilli, Condorcet, or 

 D'Alembert, yet, from being more conversant with the actual conditions of 

 a vessel when sailing through the waves, being more likely to have attained 

 results more consistent with truth, than those laborious, but too often spe- 

 culative forms, produced by the before-mentioned illustrious men. And 

 yet there is every thing about the resistance of fluids, to invite the enter- 

 prise of the most ardent geometer to a still farther investigation of this 

 deep and recondite question. Independently of the intellectual renown 

 which would be obtained by the man who shall place this beautiful in- 

 quiry in a clearer and more satisfactory point of view, who, not seduced 

 by the images of his analytical creation, is content to blend the sober re- 

 sults of experiment with those powerful operations of his calculus, which 

 enable him so often to penetrate the obscure mysteries of nature, — there is 

 an immense practical value attached to the inquiry, which few other bran- 

 ches of philosophy possess. Harvey long ago remarked, in the Annals of 

 Philosophy, " that, had the subject been one which individual industry and 

 sagacity could have successfully prosecuted, there can be no doubt but its 

 complete solution would have been long ago achieved, or at least some large 

 and important steps made towards its completion. The problem" says he 

 '* is one which involves too many difficulties for any individual to contend 

 with, unless that individual possessed talents of the very highest order, un- 

 interrupted leisure, and the necessary command of money, — three elements;" 

 says he, " not often combined in the same person -, and as the past has not 

 afforded a fortunate example of the kind, we may almost fear the future 

 will not be more propitious." Inman, the learned professor at the College 

 of Naval Architecture, remarks also in the notes to his translation of Chap- 

 man, *' that it is difficult to draw from the theory of resistances, as it now 

 stands, any particular conclusions applicable to ship-building. .The author 

 of the paper, however, having adopted the investigations of Chapman, has 

 applied them to the actual circumstances of a ship, and deduced the area 

 of a plane whose resistance is equivalent to that of the vessel when moving 

 with the same velocity. 



The portion of the paper devoted to the sails of ships might, with much 

 propriety, have been extended. This is a subject quite in its infancy, and 

 we fear that sail-making and ship-building have not hitherto enjoyed the 

 intimate connection which they ought. The inquiry is confessedly a diffi- 

 cult one, like most others relating to naval architecture, particularly in the 

 case of merchant ships, which present the most remarkable anomalies. 

 These anomalies owe their origin to the variable specific gravities of the 

 cargoes ; so that the same ship in different voyages must present different 

 values for the movements of stability, and therefore equally varied results 

 in the efforts of the sails. 



The section on the dimensions and forms of ships is one replete with 

 the most interesting inquiries. The gradual augmentation that our ships 

 of war have received in their dimensions is connected with the most inte- 

 resting and important principles. A first-rate constructed a century ago. 



