: I have read that "rubber strands" powered some of the models in the mid 1800s. What are rubber strands?
Answer : From the very start of propeller-driven model aircraft, strips of rubber have been used to spin the propeller. Alphonse Penaud of France was the first aeronautical experimenter to use twisted rubber strips to power his "Planophore." Penaud first flew his model airplane in 1871 within Paris' famous Tuileries Gardens.
Even today, model aircraft can be powered by a thin strip of rubber, usually formed into a loop and wound using a mechanical winder. The strip is similar to a rubber band, but usually made of much higher quality rubber than the band on your morning newspaper.