410 Mr. Major on [JtTN^i/, 



and length, will give it, allowing the body to be of a certain 

 sharpness and curvature. In our East India ships of 1325 tons, 

 it is f very nearly ; for the common 74 gun ship it is -i : in the 

 tables of merchant ships, Chapman gives this ratio for his 

 vessels. The calculations proposed in an article on a Digest of 

 the British Navy, in the Amiah for November last, would give at 

 once such practical guides. The plank of the bottom of our 

 ships is generally about -jVth of the whole displacement. 



The consideration of the tonnage is very properly united in 

 this article with that of the displacement. The tonnage, or real 

 burthen of a ship, is the difference ofthehght and load displace- 

 ments ; or it is the difference of the whole weight of the ship 

 with its contents, and the weight of the hull. 



The scale for tonnage, which has long been used abroad, and 

 was printed in Steel's large work on Shipbuilding, 20 years ago, 

 is an ingenious mode of expressing the tonnage of the ship at 

 different draughts of water; and which, when once done for the 

 ship, requires only the trifling correction of observing her hght 

 draught of water and displacement at every two or three years' 

 period of service, and making the allowance for the increase or 

 diminution of weight in the scale. As a ship frequently hogs or 

 breaks her sheer, the draught of water at the stem and sternpost 

 are not good guides ; in such cases a distance should be taken 

 from the ports in the middle. 



■ The common mode of estimating the register tonnage is not 

 discussed, nor is any computation proposed in its place. Among 

 our ships in general, nothing has retarded their improvement 

 and advance towards perfection, so much as this erroneous rule 

 for estimating our British tonnage. 



There can be little doubt, but that great advantage would be 

 derived to the country, by regulations being enforced for the real 

 measurement of the burden of ships. The only objection to a 

 regular calculation of the burthen of a ship is, that it would cost 

 5/. or 10/. For effecting it, a plan or draught of the ship must 

 be made, and the lines to which the ship sinks, when there is 

 only her usual portion of ballast in her, and when she is loaded, 

 must be marked ; the solid content between the two lines, then 

 being measured in cubic feet, and divided by 35, will show the 

 burthen in tons correctly. Usually, a ship is built from a draught, 

 in which case there is no occasion to measure one off from the 

 body ; but in the latter instance, the inconvenience and expense 

 would be very trifling, when compared with the numerous evils 

 attending our present mode. The draughts might easily be 

 attested, and they could be proved at any time. The origin of 

 our common rule, its evils, and other circumstances attending it, 

 would require too long a space to point out in the present arti- 

 cle ; but, from the consideration I have given it, I am bold to 

 assert, that it has been the cause of the loss of an immense deal 

 of property, and many Uvee. In the endeavours to evade the 



