WEIGHT AND SUPPOET IN SHIPS. 
443 
of the section is approximately a little more than 9^ feet, the bending- moment due to 
the pressure being about 2740 foot-tons. This is, as nearly as possible, one fourth ot 
the maximum bending-moment (11,000 foot-tons) produced by vertical forces in this 
ship; and in this respect the ‘Audacious’ resembles the ‘ Bellerophon,’ although, being 
a smaller ship, the actual amount of the bending-moment due to the longitudinal pres- 
sure is less than that in the ‘ Bellerophon.’ 
On a review of these investigations, therefore, it appears that the limiting propor- 
tions of the bending-moments due to the pressure, and those due to the vertical forces, 
might be taken at one twelfth for very long fine ships, and one fourth for ships of 
moderate length and proportions, having their principal weights concentrated amidships. 
The cases which fall outside these limits may be considered exceptional amongst modern 
ships. 
I have only determined the maximum values of the bending-moments due to the lon- 
gitudinal pressure in the preceding examples, because they are the only values having 
much practical interest, and because my chief aim has been to show that it is not proper 
to omit all consideration of the bending effect of this pressure in all cases, as is usually 
done. In long fine ships, such as the ‘ Minotaur,’ the error introduced by omitting it 
would be comparatively small for still-water strains ; but in ships of more moderate 
proportions this is not the case. Were it at all desirable we might obviously determine 
the amount, and the moment, about the neutral axis, of the pressure on any transverse 
section, in a manner similar to that employed above for the midship section, and might 
represent the results graphically by curves of moments constructed similarly to those for 
the moments of vertical forces. In fact, by using the same scales of foot-tons, we might 
combine the curves of moments for longitudinal pressure and for vertical forces, and 
obtain a single curve which should represent their joint effect. This need not be done, 
however ; for, as I have before remarked, the still-water strains experienced by a ship 
are not those which regulate the provision of strength ; and we shall see hereafter that 
it is only for still water that the longitudinal has such an effect in proportion to the 
vertical forces as to require quantitative consideration. 
The preceding considerations respecting the still-water strains resulting from the action 
of vertical and horizontal forces on a ship have been given at considerable length, be- 
cause they furnish many extensions and corrections of existing knowledge, and also be- 
cause methods similar to those here employed will hereafter be applied to the severer 
strains experienced by ships when at sea or when ashore. Besides this they have a 
special interest and importance themselves. They do not, it is true, exercise very much 
immediate influence on the distribution of material and the provision of strength in a 
ship, owing to the greater magnitude of the sea-strains ; but they constitute what may 
be termed the permanent strains on the structure, and we have seen how very widely 
these permanent strains differ under different methods of distributing the weights 
and the buoyancy. In view of the illustrations chosen, there cannot fail to result a 
fuller appreciation of this fact than could result from any general statement ; and the 
