Figure 8. Experiment E5. The bracing effect with one dorsal pneumatic tube was studied. 8.1. When the balloon was tied dorsally to the chain beam and proximally not fixed, there was no bracing effect. 8.2. The offset of the balloon from the proximal end of the chain beam demonstrates that the balloon is drawn in a distal direction. 8.3. The balloon was fixed proximally to the pivot board. 8.4. The fixation of the balloon yielded an si of 265 mm with the dorsal balloon being tensed proximally and continuing distally in a straight line. 8.5. Adding an intersegmental wedge to the chain beam with the fixed dorsal balloon resulted in an si of 405 mm. 8.6. The balloon is under full tension.