in Naval Architecture. 283 



jesty's Letters Patent for my invention, I am induced to submit 

 the following explanation of it to the consideration of the public, 

 and of those who may be interested in such a subject. 



The mechanical jirinciple upv^n which this improvement is 

 founded is that of forming a complete and integral truss or sup- 

 port from the centre of gravity (wlience the strength of the whole 

 structure should as much as possible be derived), and so con- 

 necting the parts together, by emljracing the entire fabric, that 

 any tendency to a change of figure may be j)owerfully counter- 

 acted, and as much strength be given as the nature of materials 

 will permit. 



The frame or skeleton of a ship being constructed in tlie C(.m- 

 mon way, a principal frame A (fig. 1 and 2, PI. VI), constructed of 

 metal, or of wood and metal, is introduced in the space between 

 the ribs, intersecting the vessel athwart the centre of gravity, 

 connected across the ship by a tie-bar or beam B (fig. 2), and 

 having the internal diagonal braces C, C. Also from the upper 

 part of the said principal frame, the braces DD (fig. 1), con- 

 structed of metal, are let in flush upon the outside and bolted 

 to the ft-ame timbers, and carried down in an inclined direction 

 (being that of the shortest distance over the curved surface^) 

 to the lower part of each extremity of the vessel, and connected 

 each with its opposite one, in the concave parts of the bottom, 

 l}v bolting through from one to the other, or by any other con- 

 venient method. Thus the whole frame of the ship is firmly 

 connected together, and the weight of either end (supposing the 

 ship sup])orted under the centre of gravity) is counterbalanced 

 by the other end, while the vertical strain, proceeding from the 

 weight of the whole fabric, is transferred by the tension upon 

 the braces C, C, to the principal frame A. And also for the 

 more perfect stiffening of the hull (when the spaces between the 

 tiuibers are not filled in solid), and thereby obtaining a counter 

 resistance to the weight of the middle (supposing the vessel sup- 

 ported at the ends) ; chocks or strutting pieces of timber scant- 

 ling are tailed in between frame and frame behind or within the 

 liraces, which acting as arches when confined by the braces, dis- 

 charge the weight of the vessel upon the hutments at each ex- 

 tremity, which completes the truss. And it will appear evident, 

 that so long as the truss remains perfect, not any weight or 

 pressure can alter the relative position of any of the parts, 

 whether the vessel is horizontal or inclined, unless caused by 



* The utility of kccpint; the braces in the direction of the line of shortest 

 diUame is, that it presents the direct tensimi of the braces to every en- 

 deavour of the ship to chuiigc her tit;nre, and prevents the possibility of the 

 braces being moved by any forte into a new position. 



some 



