134 Sir Robert Seppings on a new principle 
together their ribs or frames, and the arrangement of the 
materials. 
In forming the frames or ribs, half of the timbers only are 
united so as to constitute any part of an arch ; every alternate 
couple only being connected together : the intermediate two 
timbers (termed fillings) being unconnected with each other, 
and merely resting upon the outer planking, instead of giving 
support to it. Now, it must be very evident that ships so 
constructed, can by no means possess equal strength with 
those that have the whole of their timbers formed into frames 
or arches. 
This loose practice is, I believe, peculiar to the English 
merchant ship-builder ; and indeed was pursued till very 
lately even in His Majesty’s Navy, while the preferable sys- 
tem of connecting the ribs was common to other maritime 
powers. 
The principle of uniting the frames, lately introduced in 
the construction of English ships of war, might, no doubt, be 
also introduced into the mercantile navy ; which would give 
to the ships in that employ additional strength and increased 
durability, without adding to the expense of building. 
But the present mode of joining together the several pieces 
of the same rib, is also highly objectionable. It is done by 
the introduction of a third piece, technically termed a chock or 
wedge piece, (PI. VIII. Fig. 1, marked A) of which pieces the 
number amounts to upwards of 450 in a 74 gun ship, and 
not less than that number in an Indiaman of 1200 tons: (to 
which class of ships the drawings in this statement have re- 
ference.) Of these chocks not one in a hundred is ever re- 
placed in the general repair of a ship ; for they are not only 
