No person shall participate in a public performance or exhibition, or in a private exercise preparatory thereto, on a trapeze, tightrope, wire, rings, ropes, poles, or other aerial apparatus which requires skill, timing or balance and which creates a substantial risk to himself or others of serious injury by a fall from a height in excess of 20 feet, unless a safety net or other safety device of similar purpose and construction is placed between such person and the ground in such manner as to arrest or cushion his fall and minimize the risk of such injury.