ANIMAL MECHANICS. 309 

 From these values we can calculate the following Table : — 



Wing of Albatross. 



Angle. 



1 



I - V 



{I + V) sin 0 

 I — V 



IV sin 2 0 

 I — I' 



o° 



0. 03225 



4 2.6774 



54 20 



5 



0.01136 



4- 0. 9091 



'5-95 







+ 0. 5 2 5° 



°- 75 



J 5 



0.00735 



+ 0. 2941 



2. 20 



20 



0. 00675 



4 0. 1081 



0.33 



25 



0.00588 



- 0.047 1 



0. 07 



30 



0. 00538 



- 0 1882 



I-05 



35 



0 . 005 1 2 



- 0. 3282 



3. 20 



40 



0.00505 



- 0.4596 



6-35 



45 



0.00515 



0.6598 



13.27 



Sum, 



0.09S2 



2.8308 



103.37 



The sums here given are the quantities P, Q, R ; and it will 

 be observed that the elements of Q have opposite signs at 

 each side of the bisector, so that its value is the difference of 

 two groups of elements, and not the sum, as in the corre- 

 sponding quantity — 



Hence we are not surprised to find that 



from which we obtain, by equation (75), 



n l = - (29.2c;) 2 , 



m 3 = -(9.08) 2 . 



As these values are both negative, equation (72) will 

 represent an hyperbola, whose transverse axis is parallel to 

 the axis OX, and whose centre lies upon 0 Y, as shown in 

 Fig. 84. The centre of this hyperbola is found from equa- 

 tion (73), 



2P1J \ Q = o ; 



