28 Naval Architecture and 



lose a considerable portion of its impelling power, from the 

 obliquity with which it must strike the sails; hence, ccetens 

 paribus, the velocity of the vessel must also be diminished. 

 Thus, whether safety or good sailing be regarded, we see 

 how important it is to insure a counteraction to the inclining 

 power of the wind." 



The third section comprises all the useful problems in 

 Atwood's paper on the subject, printed in the " Philosophical 

 Transactions of the Royal Society," for 1798 ; but a more 

 general and elegant analysis has been used, by means of 

 which the greater part of Atwood's Paper has been com- 

 pressed into a few octavo pages. It also gives two concise 

 rules for the mensuration of all irregular bodies. These 

 rules are deduced, not from the method of differences, as is 

 usually done, but by a simple algebraical process, which 

 can only be appreciated by those who are conversant with 

 the higher branches of this science. 



The author of this tract then proceeds to give the method 

 of determining the displacement, &c., of a ship from its 

 design, which is effected in a manner intelligible to any 

 person acquainted with arithmetical operations; and there 

 can no longer, in our opinion, be any excuse, even for the 

 most ignorant shipbuilder, for neglecting the determination, 

 at any rate, of that important element of a ship — the dis- 

 placement. 



The fourth and concluding section, professing to treat on 

 the metacentre and metacentric curve, is not yet published, 

 but we hope soon to see it. It is now well known, that 

 Atwood, in controverting the propositions of Bouguer, has 

 printed glaring errors* in the " Philosophical Transactions," 

 while he has properly investigated the stabilities of the 

 isosceles wedge, in its upright and inverted states, which 

 Clairbois has erroneously discussed. 



The enterprising, learned, and remarkably acute phi- 

 lospher, M. (J. Dupinf (since created peer of France) has 

 not escaped particular notice in the " Essays and Gleanings." 

 His account of the " Progress of the French Marine, since 

 the Peace," which was read in March, 1820, before the Royal 

 Academy of Sciences, forms the subject of an article, which 



* In the observations on Atwood's Paper in the " Papers on Naval 

 Architecture," these errors are not admitted, but their justification is 

 attempted by the conductors. 



t Dupin is the sixth peer created in France, of late times, for eminent 

 attainments in the sciences and literature — such is the encouragement to 

 science in that Qountry, 



