172 TiMEHRl. 



Although it seldom happens in maritime commercial 

 transactions that any two kinds of goods only are taken 

 into a vessel, they are distin6lively laden into dead 

 weight and light freight goods, therefore, when goods are 

 to be laden, an average must be made of the densities of 

 dead weight and light freight goods, and the amount of 

 each be ascertained ; that due proportion of cargo which, 

 when reckoned in the aggregate, would not be in excess 

 of the space at disposal in the vessel's hold, nor with 

 respect to her tonnage-carrying capacity when once 

 ascertained. 



All cargo-carrying vessels not being of the same build 

 or type cannot be loaded alike. A vessel cannot be 

 loaded like a cart or truck, and it frequently occurs 

 that the bad stability and behaviour of the vessel at sea 

 is owing to improper or faulty loading and ballasting. 



The "displacement curve," "the curve of stability," 

 and *' the tons per such curve," furnished to ship-owners 

 in modern ship-building, by the ship-builder, are of great 

 use. 



The displacement curve is applied by Simpson's Rules 

 by which the volume of the immersed portion of the 

 ship can be obtained, which when assumed as water, and 

 divided by 35, (this number of cubic feet being taken as 

 weighing one ton) will give the displacement in tons. 



The displacement curve by means of scale shows the 

 draught dead weight, and free board (free board is now 

 assigned by the Board-of-Trade Rules), the mean light 

 weight of the ship and tonnage displacement, also her 

 carrying capacity or dead weight ; the total weight of the 

 ship is equal to the displacement at her draught. 



By the *' tons per inch curve" is ascertained the num- 



