40 NAVAL SCIENCES. 



A curvature often appears in the keel, which is sometimes bent more 

 than two feet in the centre. Since such deflections take place, we must 

 find the means of guarding against them. This must be effected in a 

 manner to interfere as little as possible with the stowage. PL "7, figs. 28 and 

 29, show such an arrangement, in which we must bear in mind that the 

 same space will also hold a certain number of water-casks. Fig. 28 is the 

 transverse section ; fig. 29, the longitudinal section ; a, the frame timbers ; 

 b, the cross-pieces ; c, the beams over the kelson ; d, the floor timbers ; 

 e, the filling between the cross-pieces, the floor timbers and their frames ; 

 /, frames under the deck-beams, consisting of two thicknesses bolted together 

 in order to give the necessary firmness ; g, upright supports ; and h, diagonal 

 braces and bands. All the parts must be secured in the best manner to the 

 original body of the ship. 



8. Prow and Stern. The most ancient nations ornamented the prows 

 and sterns of their vessels with rich and often with very clumsy work, 

 of which we find some specimens in the middle ages. But in the year 

 1796 the fashion of clumsy ornaments on the prow was set aside in 

 England, and galleries and carved work on the stern were also dispensed 

 with. In 1811 the plan proposed by Seppings of making the prow round 

 was introduced, and in 1816 the same shape was adopted for the stern. 

 This secured the stern against the beating of the waves and the shot of the 

 enemy, while it also gave occasion to apply new means both of attack and 

 defence. The gain in point of mechanical strength by this arrangement is 

 evident from a glance at figs. 30^ and 31^ and a proof of the advantage in 

 an engagement is shown in figs. 32 and 33, which represent the sterns of 

 the frigates Boadicea and Hamadryad. In fig. 32, there are spaces at 

 A where the guns do not range at all, which is not the case in fig. 33. 

 Fig. 30* shows the interior perspective view of a straight stern, and 

 fig. 31 * that of a round stern. 



2. Practical Part. 

 A. Ship Carpentry. 



After the plan of the ship has been drawn by the naval architect accord- 

 ing to theoretical principles, it belongs to the ship carpenter to execute the 

 model, which also demands the co-operation of numerous other mechanics. 

 Small and flat vessels are always built without any special arrangements, 

 but for large ones places constructed for the purpose are required, as the 

 so called dock-yards, lying near the water. Stocks made of oak blocks 

 are used for the foundation, with their surfaces lying oblique to the water. 



1. The Frame. The building of a ship properly commences by laying 

 the keel on the stocks. This is a beam composed of several pieces, which 

 forms the foundation of the vessel, and receives the whole length of its under 

 portion. Its height is made greater than its breadth (li lines to a foot of the 

 ship's length; and lOf lines broad to an inch in height) in order to guard 

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