31. Hang gliders are composed of rigid frame from which the fabric skin is attached, much like a triangular sailboat sail. 32. These are thin flexible sheets of gelatin or plastic which must be held in rigid frames to prevent them from sagging. 33. This gives a rigid frame with few tubes and very little body weight that does not contribute to the frame stiffness. 34. The rigid frame created by the concrete box cells made the structure 60 percent longer than any such bridge previously constructed. 35. These have a rigid frame or an enveloping box that holds a camera at a fixed position over a copy board. 36. The extremely rigid frame and strong wheel bearings prevent the torsional forces caused by this dragging motion from damaging the machine. 37. The bikes bear a passing resemblance to those used for speedway, but have a longer wheelbase and a more rigid frame . 38. By 1939, when the sprung heel and rear swingarm frames had begun to appear so rigid frames had seen their day. 39. Haubert built a prototype using his own rear suspension design that closely followed the look of the earlier Harley rigid frames . 40. Within the rigid frame of the studio floors, it serves as a metaphor for the inevitable tension between individual and collective life.
