408 Mr. Major on [June, 



science, than the laws, proportions, and rules of shipbuilding. 

 Clairbois says, " La theorie de I'architecture navale est toute 

 fondee sur des principes de I'hydrostatique et de I'hydrona- 

 mique," vol. i. p. 210. Now the fact is, that besides the theory 

 of stability, which those pure physical sciences contribute to it, 

 little else has yet been afforded by them to shipbuilding ; all the 

 rest is pure induction from facts, which must be compared by 

 mensuration and proportion, the parts of mathematics which are 

 principally useful in shipbuilding. Whatever can be measured 

 or numbered is the department of mathematics to investigate ; 

 and as in shipbuilding we cannot advance a step devoid of such 

 calculations, it is impossible to make much progress in it with- 

 out considerable attainments in geometry, mechanics, and algebra. 

 Much good has been done in this country by the circulation of short 

 rules and methods of computation, from the seminary under Dr. 

 Inman, which enable the practical man to estimate his required 

 proportions, without being in possession of that fund of know- 

 ledge, by which the rules were first discovered. 



In Chapman's large work, on Ships of War, which is not 

 translated into the trench, there is given the proportions of 

 every element in a ship ; namely, the total weights of the ship 

 and of its hull, the weights of the guns, the proportional sharp- 

 ness of the bodies, the surface of sail, &c. These proportions 

 are such as his judgment, applied to his experience, fixed upon 

 as the best ; they are, for the most part, expressed by exponen- 

 tial quantities, the indices of which are logarithms : actual trial 

 has determined them all to be good. The principle, which, by 

 \mcommon extension, has produced that fine class of vessels, 

 the 60 gun frigates, is not fully developed by him ; neither 

 Avould any of his ships sail with equal celerity to them. The 

 speed of the large frigates, first used by the Americans (though 

 they most likely obtained the draught and equipment from the 

 French, by naval engineers, in the same manner that Washing- 

 ton's army was supplied by military ones),* is, with a good side 

 wind, 13 or 14 knots an hour; while that of the Swedish ships 

 of war, which are all made to sail with one velocity, is only lU->- 

 knots, wilh a top-sail breeze. Tlio principal table of this book, 

 containiuo' all the j>ro[)ortions and quantities for ships of the line, 

 which M. Carlsund, a pupil of Chapman, did me the favour to 

 translate, is inserted in this article. 



Chapman, having discussed the principles of shipbuilding, as 

 they are generally called, in the usual routine, the same exactly 

 as in the leading papers before us, did not, in the larger work, 

 refer again to them. Dr. Inman's translation of them forms a 

 better book for the pupil's perusal than the little work under 

 consideration : there is only one exception to this remark, which 



* The common idea that they arose from the alteration, caused by treaty, of line-of. 

 battle ships to frigates, cannot account for their excellent proportions. We have altered 

 seventy-fours, but not with ctjual effect. 



