394 Analysis of Scientific Books. 



able system having been long followed by other maritime 

 powers. 



The present mode of joining together the several pieces of 

 the same rib is also open to much objection : it is done by the 

 introduction of wedge-pieces, between four and five hundred of 

 which are required in an Indiaraan of 1,200 tons ; these wedges 

 soon become defective, and communicate their own decay to 

 their attached timbers; besides which, the grain of the rib-pieces 

 is so much cut to give them the curvature required, as con- 

 siderably to weaken the general fabric; and, lastly, they occasion 

 a great consumption of materials, since the ends of the two 

 rib-pieces must first be cut away, and then replaced by the wedge. 



Another great defect of the present system is, that the lower 

 timbers are not continued across the keel; so that no support 

 is given in a transverse direction when the ship touches the 

 ground, nor any aid to counteract the constant pressure of 

 the mast ; this great sacrifice of strength and safety being made 

 for no other purpose than that of giving a passage for the 

 water to the pumps : for the same purpose, the floor-timbers, 

 which alone cross the keel, are also weakened, and after all 

 the conveyance of the water is very uncertain, and there is 

 always a residue of putrid bilge, at once offensive and injuri- 

 ous. 



Such are some of the most serious defects m our present 

 mode of ship-building. To obviate them, Sir Robert proposes 

 to connect the ends of the pieces of timber forming the ribs, 

 by circular pieces of wood, as from time immemorial has been 

 practised to unite the fellies of carriage-wheels, the component 

 parts of each rib being of shorter lengths and less curvature, 

 and consequently less grain-cut : that the timbers should uni- 

 formly be carried across the keel, leaving water-courses in the 

 joints for the purpose of conveying the water to the pumps, 

 which reaching below it allow of the removal of all stagnant 

 water ; and farther, the water-course being a smooth channel, 

 can be easily cleared, whereas at present it is not only inac- 

 cessible in places, but forms compartments for the reception of 

 putrid water. 



