424 
ME. E. J. SEED ON THE UNEQUAL DISTEIBUTION OF 
produce similar changes in the distribution of the weight and buoyancy, and conse- 
quently in the strains brought upon the ship. 
Thus far I have dealt only with the actual distribution of weight and buoyancy of 
ships floating in still water; I have next to investigate the amount of the Vertical 
Shearing (or racking) and Bending strains that result from the unequal character of the 
distribution. By “ shearing ’’-strains are here meant those vertical forces which tend to 
shear off the part of a ship or girder on one side ; and by “ bending ’’-strains are meant 
those moments resulting from the unequal distribution of weight and buoyancy that 
tend to alter a ship’s longitudinal curvature. In order to give exactitude to my re- 
marks, I will take the case of the 4 Victoria and Albert.’ The buoyancy and weight of 
this ship have already been calculated for every 20 feet of the length, and the results 
have been represented by the curves DD and WW in Plate XVI. fig. 1. It will be 
obvious that at any station in fig. 1 the length of the ordinate intercepted between those 
two curves represents the resultant vertical force (that is, the excess of weight over 
buoyancy, or vice versa) acting on the 20-feet division to which the station corresponds. 
If the weight be in excess, the resultant force of course acts downward ; and if the 
buoyancy be in excess, the resultant force acts upward. Knowing therefore the amounts, 
directions, and points of application of all such vertical forces, it is possible to calculate 
their shearing and bending effect at any transverse section by the simplest mechanical 
methods. 
A graphical method may again with advantage be applied to represent these operations ; 
and in Plate XVI. fig. 7 I have given an example of its application to the case of the 
4 Victoria and Albert.’ The base-line A B represents, as in fig. 1, the length of the ship, 
and the ordinates dotted in fig. 7 correspond to those drawn in fig. 1, while those drawn 
in fig. 1 correspond to the imaginary transverse planes of division of which the positions 
are shown midway between the ordinates in fig. 7. On the dotted ordinates lengths are 
set off representing on a certain scale the distances between the curves 13 D and W W on 
the corresponding ordinates in fig. 1, and through the points thus obtained the curve L L 
in tig. 7 is drawn. This is known as the curve of 44 loads,” or resultant vertical forces, its 
ordinates representing in direction and position the excesses of weight over buoyancy, 
and of buoyancy over weight. Where there is an excess of weight, the ordinate repre- 
senting it is measured downwards below A B, and where there is an excess of buoyancy 
the ordinate is measured upwards. In this case, as in the curves of weight and buoy- 
ancy previously constructed, we may pass from ordinates to areas, and regard the latter 
as representing the excesses or defects of buoyancy on a certain scale. We must here, 
however, add the convention that defects of buoyancy shall be represented by areas lying 
below the line A B, and excesses of buoyancy by areas lying above A B ; and in esti- 
mating the excess or defect of buoyancy on any part of the ship we must take the alge- 
braical sum of (i. e. must integrate) the areas of the loops of the curve LLL corre- 
sponding to that part. The scale of areas for this curve is marked on the diagram. 
It will be obvious, therefore, that the curve of loads L L represents, in a manner more 
