Sonometer Box with Tuning Fork, set/2

Sonometer Box with two 440Hz tuning forks, one adjustable with mass. For demonstrating the production of 'beat' frequencies. One fork is provided with an adjustable mass by means of which a frequency may be shifted from the normal 440Hz. When both forks are sounded a clearly audible "beat' is provided. Its rate depending upon the difference in frequencies between the forks.