Set of two resonance boxes with extra heavy aluminium forks having double the duration of audible vibration than the ordinary forks. One fork is weighted and can be adjusted over range of about 30 Hz. forks are of different lengths 19.4 cm and 17.5 cm approx.
To demonstrate resonance, sympathetic vibrations, and beat phenomenon. The two precision-made bars are mounted on a single solid resonance cavity. The cavity has two chambers with one bar tuned to 440Hz. The other to 441Hz. Includes: hammer and instructions. Size: 13.78" L x 7" W x 4.13" H Grades 6+
