THE LONGITUDINAL STRENGTH OF RIGID AIRSHIPS. 149 
If the support at A, were removed, the panel would distort, the frame (2) moving 
upwards until T = 0. Under the assumed conditions this does not occur, and we have: 
T = Q cosec gd 
Case 2. Tensile P-forces and a Q-force act on the panel.—As in Case 1, there is only 
one wire, and tensile P-forces cause the girders to elongate, but no support is found at A, 
and an independent shearing or Q-force is acting on frame (2), producing a downward de- 
flection. See Figs. 3 and 4, the latter of which shows in detail the deflections of the joint C,. 
We suppose first that only the shearing force is active. Under the action of shearing 
C. goes to Cy) creating a tension T in the wire, a contraction Av, in the c-bar and a ver- 
tical deflection A yp) in frame (2). 
T = Q cosec 9, ei) F,= T cos ¢= Q cot ¢. 
Fl ees Q/ cot @ 
IX tp ay Be 
i aEp akEp 
(contraction). 
