SHIP-BUILDING. 



Operation for the Plane of the Second Horizontal Water-Line. 



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

 from 37, its liril ordinate. 



Diftaiit rroilufts. 



Ft. In. from a;. Ft. III. 



Half of 37 ordinate is o 9 



Whole of 36 - - 22 Mult, by i = 2*2 



35 - - 30 '2=60 



34 - - 4 3 3 = '2 9 



33 - - 61 4 = 24 4 



32 - - 81 5 = 40 s 



31 - - lo 3 6 = 61 6 



30 - - 13 4 7 = 93 4 



29 - - 15 10 8 = 126 8 



28 - - 19 o 9 = 171 o 



27 - - 22 o 10 = 220 o 



Half of 26 - - 125 11=1 36 7 



Sum 

 Multiply by 



Area 



117 2 Sum 894 9 



2 9 dift. between ord. 2 9 



322 



Divide by the fum of the ordinates - 117 2)2460 6| 



21 o 

 6 9 



27 9 



Centre of frravity ----- 



Diltance of the ordinate 37 from the aft-fide J 



of the rudder - - - - -J 



Centre of gravity from aft-fide of the rudder 



Dittance of the centre of gravity of thcj 



feftion of the rudder and ftern-poft from > 3 5 



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



To find the centre of gravity of the plane between 26 

 and O, from 26, its firfl ordinate. 



Diftjiit Proilufls. 



Ft. In. from ib. Ft. In. 



Half of 26 ordinate is 12 5 



Whole of 22 - - 32 2 Mult, by I = 32 2 



18 - - 36 o 2 =; 72 o 



14 - - 37 10 3 r= 113 6 



10 - - 39 2 4 = 156 8 



6 - - 39 6 5 = 197 6 



2 - - 39 6 6 = 237 o 



(i) - - 39 6 7 = 276 6 



B - - 39 4 8 = 314 8 



F - - 38 10 9 = 349 6 



K - - 36 o 10 = 360 o 



Half of O - - 14 4 11 = 157 8 



Sum 

 Multiply by 



Area 



404 7 Sum 2267 2 



II o dift. between ord. 11 o 



4450 5 



Divide by the fum of the ordinates - 404 7)24938 lo 



Centre of gravity - . - . - 



Diltnncc of the ordinate 26 from the aft-fide \ 



of the rudder - - - . .j 



61 7 



37 O 



Centre of gravity from aft-fide of the rudder 98 



Vol. XXXn. 



li 



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

 from O, its fird ordinate. 



DiPiani Produfls. 



Ft. In. from O. Ft. In. 



Half of O ordinate is 14 4 



Whole of P - - 256 Mult, by i = 25 6 



Q - - 23 o 2 = 46 o 



R - - 19 o 3 z^ 57 o 



S --162 4= 64 8 



T --120 5=600 



U - - 8 8 6 = 52 o 



Half of W-- 20 7=140 



Sum 



Multiply by 



Area 



120 8 Sum 319 2 



2 9 did. between ord. 2 9 



33' 10 



Divide by tlie fum of the ordinates 



120 8)877 ^ 



Centre of gravity ----- 73? 



Dirtaiice of the ordinate O from the aft-fide 7 q 



of the rudder - - - - -J 



Centre of gravity from aft-fide of the rudder 165 35 



Centre of gravity of the ftem and kneel 



before W j ^ ^ 



Diftance of the centre of gravity of the \ 



feftion of the ftem and knee from the V 179 6 



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



Areas of the feveral planes, and their momenta. 



Ft. Iiu Ft. In. 



Area of the after-plane 322 2^ 

 322 2\ Mult, by 27 9 its momentum = 8941 3J 

 Area of the midftiip-plane 44JO 5 

 4450 5 Mult, by 98 7 J its momentum = 438968 77'- 

 Area of fore-plane 331 10 

 331 10 Mult, by 165 35 its momentum = 54842 4^- 

 Area of rudder and poll 9 6 

 9 6 Mult, by 3 5 its momentum = 32 5^ 



Area of the ftem and knee 5 10 

 5 10 Mult, by 179 6 its momentum = 1047 i 



J119 9i Whole areas. Sum of momenta 503831 9^ 



Now J03S31 ft. 9i in. divided by 5119 ft. 9^ in. gives 

 98 ft. 4j in., the diftance of the centre of gravity of the 

 whole fidlion of the fecond horizontal water-line from the 

 aft-fide of the rudder. 



.iX 



Operalien 



