In downtown Austin near state buildings you never know what you will find memorialized. We happened to notice this at a tiny pocket park near a building on 11th Street. A plaque nearby identifies it as the "Thornton Ferry Boat Propeller." This came from a propeller-driver ferry boat that ran between Galveston and Port Bolivar between 1959 and 2000. The propeller weighs 3000 pounds! The ferry boat was named for a state official (Eli Thornton) so this is, I guess, a memorial to him. Today the ferry boats use some other sort of propulsion system.called Voith Schneider which has a much less nostalgic propeller system.