SHIP-BUILDING. 



operation for the Plane of the Third Horizontal Heater-Line. 



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

 from 37, its tirft ordinate. 



^ Diftant 



Ft. In. from 3". 



O 9 



Produas. 

 Ft. In. 



Half of 37 ordinate is 



Whole of 36 - - 3 



35 - - 6 



34 - - 9 



33 - - '2 



32 - - •? 



31 - - 21 



30 - - 24 



29 - - 27 



28 - - 30 



6 Mult, by I 



Half of 



27 

 26 



bum 

 Multiply by 



Area 



3 

 12 



27 

 49 

 86 



127. 

 171 



8 = 220 



9 = 270 



10 = 320 



11 = 187 



2 — 



3 == 



4 = 



5 = 



6 = 



7 = 



Sum 



1476 



9 dill, between ord. 2 



Divide by tlie fum of the ordinates - 2or 6 ) 4060 4^ 



Centre of gravity - . . . . 



Dillance nf the ordinate 37 from the aft-fide 1 



of the rudder - - - . . j 



Centre of gravity from aft-fide of the rudder 



Diftance of the centre of gravity of the"| 

 feftion of the rudder and ftern-poft from > 

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



20 

 6 



26 lof 



3 5 



To find the centre of gravity of the plane betwreen 26 

 and O, from 26, its firft ordinate. 



Ft. In. 

 Half of 26 ordinate is 17 o 

 Whole of 22 



18 - 



Diftant Produfls. 

 from 26. Ft. In. 



39 1 Mult, by I = 39 i 



Half of 



H 



10 



6 



2 



(0 



B 



F 



K 



O 



41 

 42 

 43 

 43 



43 8 



43 8 



43 8 



43 6 



41 8 



i8 8 



2 = 82 



3 = 127 



4 = 172 



5 = 218 



6 =z 262 



7 = 305 8 



8 = 349 4 



9 = 391 6 



10 = 416 8 



11 = 205 4 



Sum 

 Multiply by 



Area 



461 2 Sum 2569 10 



II o diit. between ord, 11 o 



5072 10 



Divide by the fum of the ordinates - 4612)28268 2 



Centre of gravity - - . . . 



Diftance of the ordinate 26 from the aft-fide l 



of the rudder r 



Centre of gravity from aft-fide of the rudder 98 S' 



6' 34 

 37 o 



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

 rom O, its firft ordinate. 



Half of O ordinate is 



Whole of P - - 



Q - - 



R - - 



S - - 



T - - 



U - - 



W - - 



X - - 



Half of Y - - 



Diftant 

 Irom O. 



Prodiifls. 

 Ft. In. 



Ft. In. 

 18 8 



35 2 Mult, by I = 35 2 



32 10 2 = 65 8 



29 6 3 = 88 6 



26 6 4 = 106 o 



22 o 5 = no o 



178 6 = 106 o 



12 o 7 = 84 o 



30 8 = 24 o 



in 9=83 



Sum 

 Multiply by 



Area 



198 3 



Sum 



627 



2 9 dift. between ord. 2 



545 



Divide by the fum of the ordinates - 198 3 ) 1725 10^ 



Centre of gravity . - - . - 



Dittance of the ordinate O from the aft-fide 7 



of the rudder - - - - - j 



8 

 158 



Centre of gravity from aft-fide of the rudder 166 8f 



5 Y 



he~j 



Centre of gravity of Item and knee before Y is 

 Diftance of the centre of gravity of the 

 feftion of the knee, from the aft-fide 

 the rudder .... 



o 6 

 183 3 



Areas of the feveral planes, and their momenta. 



Ft. In. 



554 H 



5072 10 



545 



10 li 



Area of the after-plane 554 li 

 Mult, by 26 lof its momentum 

 Area of midfhip-plaiie 5072 10 

 Mult, by 98 3A its momentum 

 Area of fore-plane 545 2^ 

 Mult, by i66 85 its momentum 

 Area of rudder and poft 10 1 5 

 Mult, by 3 5 its momentum 

 Area of item and knee i 2 

 Mult, by 183 its momentum 



Ft. Id. 

 14903 71 



498616 I Of 



90881 7I 



34 7? 



213 95 



6183 51 Whole areas. Sum of momenta 604650 6| 



Now 604650 ft. 6iin. divided by 6183 ft. 5|in. gives 

 97 ft- 9; •"•> the diftance of the centre of gravity of the 

 whole fedion of the third horizontal water-line from the 

 aft-fide of the rudder. 



Operation 



