SHIP-BUILDING. 



Operatian for the Plane of the Firjl or Lower Horizontal Water-Line. 



To find the centre of gravity of the plane abaft 26, 

 from 37, its firft ordinate. 



Half of 37 ordinate is 



Whole of 36 - - 



35 - - 



34 - - 



33 - - 



s* - - 



31 - - 



30 - - 



29 - - 



28 - - 



Ft. In. 



o 8 



Diftant 

 from 37. 



Produas. 

 Ft. In. 



Half of 



27 

 26 



7 

 10 



2J 



8' 



5 



I 

 10 

 II 



o 



2 



O 



Mult, by I = I 



I 

 2 

 3 

 4 

 5 

 6 



7 

 8 



9 

 10 

 II 



3 



6 



10 



17 



H 



/ 

 8 



7i 

 8 

 I 

 6 



= 33 10 



= 47 



= 63 



= 81 



= SS 



4 

 o 

 8 

 o 



Sum 

 Multiply by 



Area 



47 4^ Sum 344 iiJ 



2 9 dift. between ord. 2 9 



130 3i 



Divide by the fum of the ordinates - 47 4^ ) 948 7 1 



Centre of gravity ..... 



Diftance of the ordinate 37 from the aft-fide 7 



of the rudder - - - - . J 



20 O; 



6 9 



Centre of gravity from aft-fide of the rudder 26 9^ 



Diftance of the centre of grravity of the "J 

 feftion of the rudder and Ttern-poft from > 

 the aft .fide of the rudder is - - -J 



3 5 



To find the centre of gravity of the plane between 26 

 and O, from 26, its firft ordinate. 



Divide by the fum of the ordinates - 3148)19866 o 



Centre of gravity - - . . . 



Diftance of the ordinate 26 from the aft-fide ") 



of the rudder - - . . . f 



Centre of gravity from aft-fide of the rudder 



63 

 37 



100 



To find the centre of gravity of the plane before O, 

 from O, its firft ordinate. 



Diftant Produflt. 

 Ft. In. from O. Ft. iu. 



8 6 



14 8 Mult, by I = 14 8 



12 3 2 = 24 6 



98 3 = 29 o 



70 4 = 28 o 



4 4 5 = 21 8 



on 6=56 



Half of O ordinate is 



Whole of P - - 



Q - - 



R - - 



S - - 



T . - 



Half of U - - 



Sum 

 Multiply by 



Area 



57 4 Sum 123 4 



2 9 dift. between ord. 2 9 



157 8 



Divide by the fum of the ordinates 



57 4)339 2 



Centre of gravity ..... 



Diftance of the ordinate O from the aft-fide \ 



of the rudder - - - - . J 



5 II 

 158 o 



Centre of gravity from aft-fide of the rudder 163 11 



Centre of gravity of the Item and knee \ 

 before U- - - - --J 



Diftance of the centre of gravity of the"j 

 fetlion of the ftem and knee from the > 

 aft-fide of the rudder ... -J 



2 7 

 176 1 



Areas of the feveral planes, and their momenta. 



Ft. In. Ft. In. 



Area of the after.plane 1 30 3f 

 130 3^ Mult, by 26 9^ its momentum = 3487 8f 

 Area of midftiip-plane 3461 4 

 3461 4 Mult, by 100 1 5 its momentum ^ 346566 o 

 Area of the fore.plane 1578 

 IJ7 8 Mult, by 163 II its momentum = 25844 2| 

 Area of rudder and poft 9 o 

 9 o Mult, by 3 5 its momentum = 3° 9 



Area of ftem and knee 6 5^ 

 6 5-1 Mult, by 176 I its momentum = 1 137 2| 



3764 8 J Whole areas. Sum of momenta 377065 lof 



Now 377065 ft. lol in. divided by 3764 ft. 8| in. gives 

 TOO ft. if in., the diftance of the centre of gravity of the 

 whole feftion of the firft or lower horizontal water-hae 

 from the aft-fide of the rudder. 



Operation | 



