SHIP-BUILDING. 



placed on the draught. However operofe and difficult the 

 calculations neceffary to afcertain the capacity, ftability, 

 &c. of (hips may be, it muft be allowed that it will require 

 the utmoft care in the execution, to find the exaft dimenfions 

 of the feveral feftionn of the (hip from the draught, (efpe- 

 cially as every dimenfion in the (hip is forty-eight times 

 bigger than their fimilar ones on the draught, fuppofing it 

 to be drawn by a quarter of an inch fcale to a foot), as an 

 error of a quarter of an inch in the draught, which is only 

 the forty-eighth part of a real inch in the (hip, will occafion 

 an error of 110,592 cubic quarters of an inch in the (hip. 



provided the error be in all the three dimenfion'!, viz. length, 

 breadth, and depth. Great prccifion, indeed, mud be ufed 

 to mcafurc to a quarter of an inch in Plate I., feeing it is 

 only drawn, for convenience, to an ciglith of an inch fcale. 

 But as thefe calculations cannot be made with too great 

 an cxaflnefs, the body had better be expanded on the mould- 

 loft floor to the full fize, and then the various dimenfions 

 may be taken very accurately. 



The cftimated weight of a 74-gun (liip, as fitted for fea, 

 with fix months' provifions on board, is given in the follow- 

 ing table. 



An Eftimate of the Weight of the 74-Gun Ship, P!ate I., as fitted for Sea, with Six Months' Provifions, Guns, &c. 



Vol. XXXll. 



3 IT 



Br 



