How to make a trampoline out of inner tubes

Co-evolution magazine socks it to the man in their Autumn 1977 issue with this spectacular Poor Man's Trampoline made from cunningly cut strips of old tractor or truck inner tubes. The strips are knotted together using square knots - it's like giant macrame.

All you need are inner tubes, heavy shears, clothes line, parachute cord, a big hook, and a healthy disregard for health and safety as you watch up to four children propel themselves up towards the ceiling at great speed on the end of a springy rubber cord.

"Preventing cracked heads becomes an exercise in high-speed, well-coordinated cooperation," warns the author. Quite.