Pair Of Tuning Forks On Resonance Boxes

Comprises Two Matched Nickel Plated Tuning Forks Of Frequency A (426.6), Each Mounted On Top Of Hollow Wooden Box Open At One End. One Fork Is Provided With A Sliding Mass On One Prong By Means Of Which Its Frequency Can Be Varied From The Nomil 426.6Hz. When Both Forks Are Sounded A Clearly Audible ‘Beat’ Is Produced, Its Rate Depending Upon The Difference In Frequency Between The Forks. (Pair Of Tuning Forks On Resonce Boxes)