Dr. Young’s Remarks on the 
526 
of the arrangement, to be fully as much as can ever happen; 
the greatest fall of the surface will be one foot in 44, and the 
length of the brace will be diminished or of an inch 
in the length of six feet, which, with a moderate allowance 
for the partial yielding of the fastenings, it will be perfectly 
capable of supporting witliout being crippled, although indeed 
it could scarcely support much more. It is obvious, however, 
that this supposition in many respects far exceeds the utmost 
that can possibly happen : and it would even require a greater 
force to produce such an effect on the braces, than any which 
the ship actually sustains. In order to calculate the magnitude 
of the greatest strain which these pieces could support, it will 
be safest to proceed on the supposition, that each square inch 
of the section of good oak timber is capable of resisting the 
pressure of four tons on an average : it will then appear that 
a single series of such braces, as Mr. Seppings employs, ex- 
tending throughout the length of each side of the ship, would 
support a weight of 143 tons, in whatever way the force 
counteracting it might be applied ; and estimating the effect of 
all the braces and riders as equivalent to about four such series, 
the whole would resist a force of 570 tons ; while the greatest 
force derived from the distribution of the weight, together with 
the action of such waves as we have considered, amounts to 
about tons : so that the strength of these braces can 
scarcely be insufficient to support the pressure, unless the ship 
should be left dry, resting on the middle of her keel, and the 
braces should be abandoned by all the other parts, which 
usually cooperate with them.* The fastenings must indeed 
* If a jointed parallelogram, composed of pieces of invariable length, having one 
of its sides fixed in a vertical position, be supported by a diagonal brace, the compres- 
