478 EXPLANATION OF THE PLATES. 



making the base of the fabric perfectly secure and strengthening the most important 

 part of the ship. Vide section, Plate CII. 



The timbers composing the frame of the lower part of the ship, are strengthened 

 by solid fillings caulked and made water-tight from the keel to about four feet above 

 the turn of the bilge, so that if the vessel should by accident at any time take the 

 ground, and disturb the outer or false keel with such part of the planking on the 

 lower part of the bottom as might by any possibility come in contact with the rocks, 

 yet she would be perfectly safe, as the inner or solid keel could not be removed but 

 only ground away in such places as bore against the shore, it being firmly attached 

 to the fabric. 



The lower part of the stern post (vide Plate C.) is united to the after end of the 

 solid keel, by a knee piece scarphed and grooved at the after end, and scarphed and 

 dowelled at the fore end, bolted through and securely clenched on a ring at the end 

 of each bolt, instead of the old method, a mortice and tenon, as generally adopted by 

 shipbuilders in this and all other countries, which insufficient mode has caused the 

 loss of many vessels. The lower piece of stem is scarphed to the foremost piece of 

 keel horizontally, and not with a vertical or side scarph in a square boxing, that 

 dangerous system so long practised in vessels of all descriptions, but on the con- 

 trary, forming no projecting butt, to the fore end of the keel ; should the gripe be car- 

 ried away by the ship striking the rocks, the remaining surface of the keel and bottom 

 would offer no resistance to the cable after such an accident, but would retain a 

 similar shape to the original form of the ship when in its perfect state. 



The whole frame is connected together by iron braces on the inside, placed in a 

 diagonal direction, let into the timbers about half their thickness, and having one bolt 

 passing through every timber for their security, and a wood trussing of four-inch 

 plank in the opposite direction, to prevent the hull of the vessel from hogging or 

 altering her form ; between the wood trussing, the timbers are covered by board of 

 one inch and a half thick, secured at the ends on a cant two inches square, so that 

 the board may bear only on the cants, and allow a current of air to pass throughout 

 the ship. 



The upper deck beams are secured to a shelf or thick clamp, which extends all 

 fore and aft on both sides of the ship and embraces every timber ; the beams are 

 dowelled and bolted to the said clamp, their ends extending without over the top- 

 side to connect the sponcing, being scored and let into the sponcing timbers, dovetailed, 

 and bolted in a fore and aft direction ; a thick strake is then worked on the outside 

 on the ends of the beams against the timbers forming a sheer strake, scored half way 

 between the said timbers to meet the thick water-way, which is scored in like man- 



