Each valve was a wood disc faced with leather on both sides; one face had a center hole leading to a pocket of a larger diameter in the wood.
One face had a center hole leading to a pocket of a larger diameter in the wood. Each valve was a wood disc with leather facing on both sides.
Each valve was a wood disc with leather facing on both sides. One face had a center hole leading to a pocket of a larger diameter in the wood.
Each valve was a wood disc with leather facing on both sides. One face had a center hole leading to a pocket of a larger diameter in the wood.