284 Improvcmetits in Naval Architecture. 



some shock that would go near to effect the total destruction of 

 the whole fabric. 



The foregoing description being confined to the method of 

 trussing smaller ships or vessels, the manner of extending this 

 system (which with a little modification is applicable to ships 

 of the greatest magnitude) is shown by figure 3, in which A is 

 the principal frame; and B, B, the braces, as already described ; 

 CC are auxiliary l)races ; D, D, minor principal frames, one ia 

 the fore and the other in the after part of the body ; EE are 

 minor braces ; and F is an horizontal brace, connectiiig the 

 heads of the minor braces, and forming a kind of longitudinal 

 hoop to the upper part of the structure*. Chocks or strutting 

 pieces'' are also tailed in at the back of these braces, similar 

 to those before described, when the spaces are not filled iu 

 bolid. 



In ships of war tiie disposition of the principal braces ought 

 to be so regulated as to be but little exposed to be shot away, 

 and auxiliaries should be employed below low-water line, for 

 additional security. 



The braces before described are made of flat bars of metal in 

 ))ieces of convenient length, so adjusted that the parts at which 

 they are joined together, fall in the spaces between the ribs of 

 the vessel, being connected by scarf joints wedged up for the pur- 

 pose of equalizing the tension. The outer surface of the braces 

 is kept flush with the frame timbers, and the bolt-holes in ail of 

 them arc countersunk to receive the heads of the bolts, so that 

 HO part may present any obstruction to the planking. 



In addition to the security afforded by this principle of truss- 

 ing in constructing the ribs, I affix upon the sides over each 

 butting joint of tlie timbers of which the rii) is composed, a plate 

 of iron or other metal extending above and below it, and bolted 

 through the rib, by v.hich means the ribs acquire great addi- 

 tional strength ; an object of the first importance, even if oidy 

 partially employed in assisting the weaker parts, and protecting 

 those most exposed to injury; as, in cases of a ship's grounding, 

 it commonly ha|)pens that the floor timbers are forced in at one 

 end, and the first futtocks broke oft", while, by the tendency of 

 the sides to sink, a transverse curvature is occasioned by a failure 

 of the parts situated near the head of the floor timbers. In 

 many other respects the emplovment of these iron clamps will 

 be found of the most essential service. 



Such is the general arrangement and application of my inven- 



* As tlie tension upon tlie liorizontul brace F is in die direction of the 

 planking, this brace is not iirccbsary to be Ubcd except in cases where great 

 additional strength is required. 



tion 



