Dr. Young’s Remarks on the 
328 
liad once failed, with greater ease than many other parts of 
the fabric. 
It may be questioned how far it is allowable to omit any 
part of the inner planks between the ports, for which the braces 
are a substitute, on account of their utility in securing the butts 
of the planks, which are always made to shift where they are 
supported by this subsidiary tie : but with the outer planking 
which remains, and with the partial assistance of the braces, 
to say nothing of that of the shelf pieces, it can hardly be 
believed, that the tie is more likely to part between two ports 
of the same deck, than immediately over one of them. 
It has been very ingeniously observed, that arching is not 
only a part of tlie evil occasioned by a ship’s weakness, but 
that it has an immediate tendency to afford a partial remedy 
for the cause which produces it, by making the displacement 
greater at the extremities of the vessel, and smaller in the 
middle : but, in fact, this change appears to be too inconsider- 
able in its extent, to produce any material benefit : the strain 
at the midships being diminished by each inch of arching only 
66 tons, supposed to act at one foot : so that very little relief 
is obtained from the change, in comparison with the whole 
strain. 
The case of the Kent, which broke in a remarkable degree; 
notwithstanding the employment of riders of large dimensions, 
is perfectly rcconcileable with the principles which have been 
laid down : indeed these riders, which made an angle of a few 
degrees only with a vertical line, could have so little effect 
either on the strength or on the stiffness of the structure, that 
tliere was not the slightest reason to expect any material 
advantage from their application. 
