Ships and Shipping. 159 



draught increases, and when she goes from the river to 

 the sea it diminishes. The Load Line Committee some 

 years ago took samples of water and found the densest 

 water on the British Coast to be 1.025 ounces for one 

 cubic foot. Among other features in the displacement 

 of a ship the consumption of stores has some effe6l in 

 lessening the displacement. It is necessary, therefore, 

 in loading a ship to the proper load mark, to determine 

 the specific gravity by a hydrometer or otherwise of the 

 water in which she is loaded, and especially so as one 

 or two inches with low freights may be of considerable 

 importance to the ship-owner. If it is required that the 

 ship should leave the port with the legal freeboard, it 

 should be settled beforehand how deep the ship can be 

 loaded below the load water-mark, so that when she 

 reaches the sea she will float with the regulation free- 

 board. This can be done by a scale of displacement ; 

 but this is not always at hand, and it is often necessary 

 to ascertain the difference between the draught in salt 

 water, brackish water, and fresh water approximately. 

 A simple rule which gives results not very wide of being 

 corre6l is, that a ship, in going from water of i.ooo speci- 

 fic gravity to water of 1.025, rises one quarter of an inch 

 for every foot of her mean draught. We will suppose how- 

 ever a ship loaded in brackish water, then the redu6lion 

 of freeboard for a ship of 16 feet of moulded depth with- 

 out ere6lions, loaded in fresh water, would be 3 inches, 

 but the specific gravity of the water in which she is 

 loaded is i.oio; the extent to which she might be loaded 

 beyond the load mark so as to have the legal freeboard 

 would be as follows : — 



Multiply 3 inches by 15 the difference between 1.025 



