His Majesty*s Ships of IVdr. 28^ 
This disposition which, in every wooden fabric is well known 
to the meanest mechanic, to be the weakest, is particularly 
so in a ship, the immense body of which, subject to violent 
action from impulses in every direction’ is sustained by a 
greater pressure on the centre than the extremities, arising 
chiefly from the difference in the fore and after parts of the 
body, to that of the midship, or middle part. 
From the want of a continued succession of support from 
the centre to the extremities, originates the tendency to arch- 
ing, or hogging. This tendency shews itself in a ship from 
the moment of her launching ; from whence some idea may 
be formed to what extent it will be carried in a troubled sea, 
when in the act of pitching she is borne up by the fluid only 
in her central part, while the head and stern are forsaken, 
and therefore unsupported by the water. 
If a straight line be drawn from the head to the stern of a 
ship, whilst on the slip, or in the dock, no sooner has she en- 
tered her own element than each end of this line will be found 
to have dropped from two to five or six inches, in consequence of 
the weakness of the fabric, and the two extremes wanting the 
quantum of support which the fluid gives to the central part. 
The length of a 74, gun ship being 170 feet or more, it re- 
quires but little knowledge of the strength of timber to per- 
ceive that planking of that length, however thick, or in 
whatever way joined or put together, must, under the present 
system, bend with its own weight. The fastenings, and con- 
sequently the connection of the several parts of the fabric, 
must therefore sutfer for the want of stiffness^ and a change 
of form is the consequence. 
This may be shewn by putting together four pieces of wood, 
