Clamped Square and Round Brass Vibrating Plates

This apparatus came with the holder and two brass plates, one round and the other square. The plates could be made to vibrate, perhaps by stroking with a violin bow or tapping with a mallet, and the resulting sound examined. They could also be mounted with the plate horizontal. Then if a light powder, such as lycopodium powder, was placed on the plate, the nodes of standing waves in the plate when it was bowed or tapped could be seen in patterns of the powder.

ac_056

Acoustics

Display Case H3

1895