Nautical Economy. 9t 



the Navy, In the preface of his work on the *« Preservation 



of the Navy." — " While the Dutch possessed and encou- 

 raged Witsen, — the French, Bouguer, Du Hamel, Clairbois, 

 Borda, and Romme, — the Spaniards, Juan, — the Germans, 

 Eliler, — and the Swedes, the celebrated Chapman ; the 

 English neglected the only work which they possess on this 

 subject, that can lay any claim to science*, and suffered its 

 author, whom tradition represents to have been a man of 

 the most amiable manners and correct conduct, to live and 

 die a working shipwright in Deptford Yard." In the fol- 

 lowing page, in adverting to the students of the School of 

 Naval Architecture, he says, " it is to be hoped that their 

 ardour may not be damped, but that the encouragement 

 will be extended to them which has hitherto, in this country, 

 been withheld from those who have endeavoured to promote 

 the difficult but useful science of constructing ships." 



On the paper inserted by Sir Robert Seppings, in the 

 Phil. Trans, for 1814, on his diagonal system of ship-build*- 

 ing, which is here reprinted for convenient circulation, it 

 behoves us to make a few remarks. The adoption of this 

 plan is a great triumph over inveterate prejudices, and we 

 are inclined to bestow praise on the introduction of this 

 new mode of carpentry ; but we do not conceive we should 

 abandon investigation respecting it. The late writers on it, 

 in addition to Sir Robert, are Baron Dupin, Dr. Young, 

 and Mr. Knowles. Of these Dupin, being a naval archi- 

 tect, has by far surpassed the others in its discussion. Dr. 

 Young's more limited acquaintance with ships has neces- 

 sarily confined his illustrations, though his elegant analysis 

 has much enriched the subject. Mr. Knowles's descriptive 

 view is unassisted by mathematical investigation. 



Dupin remarks, in his paper, in the Phil. Titans, of 1816, 

 that the princij^le has often been recommended in theory, 

 but found deficient in practice. He says, introducing the 

 subject, " The old French builders saw so distinctly the 

 truth of the principle now produced by Mr. Sep^^ings, that 

 they even put it in practice for the same purpose to 

 strengthen their ships, and to prevent arching." Again, 

 ** Chaucot, a French ship-builder, obtained the prize, in 

 17.55 (of the Royal Academy), and in a Treatise very little 

 known, reproduced the idea (of Bouguer and Du Hamel) 

 on this point." In subsequent remarks he observes, that 

 Groignard, in 1759, proposed, and that Clairon des Lau- 



* A Treatise on Ship-buildhig and Navigation, by Mungo Mum* 

 1754, 



