Paper riders on a string predated Chladni’s sand as a nodal-line visualization.

Evidence

A demonstration Sauveur made popular long before Chladni invented his visualization of nodal lines in bowed plates used small paper “riders” along a string. When set to vibrating in one of its pure sinusoidal modes, the clips are promptly ejected from the antinodes, but remain quietly riding on the string if placed at the nodes. Chladni’s sand on glass and metal plates is the exact analog of this, extending the visualization of nodal points on a string to nodal lines on a two-dimensional surface. — Eric J. Heller, Why You Hear What You Hear- An…, 1381

Categorization

• SHARE: A delightful history nugget for anyone interested in experimental visualization techniques predating modern imaging.