Three Max Kohl Scientific Laboratory Apparatus, 19th Century,
German cast-iron and brass scientific instruments with an acoustic theme:

A Chemical harmonica (or a singing flame demonstration apparatus). Glass tubes of graduated lengths fit within holes in the support bar and over four burners with brass taps producing sound; A Kaleidophone on a wooden base with a Max Kohl plaque, used to demonstrate acoustics; a Max Kohl disc raised on a tripod base with a turned wood handle that raises the disc. With a brass acoustic resonator on a rod by an unknown maker.

Largest Dimensions: H: 18 1/8 x W: 13 1/2 x D: 7 in. Glass tubes are missing from the singing harmonica. All lots have imperfections or the effects of aging. Gray's Auctioneers shall have no responsibility for any errors or omissions.