Accession No

5176

Brief Description

crova’s disk and terquem’s slide to demonstrate harmonic motion, by E. Leybold’s Nachfolger, German, 1900 (c)

Origin

Germany; Cologne

Maker

E. Leybold’s Nachfolger

Class

physics; demonstration

Earliest Date

1880

Latest Date

1920

Inscription Date

Material

glass; metal (cast iron, brass, oxidised brass); rubber

Dimensions

Terquems slide holder height 72mm; breadth 163mm; disk holder height 135mm; breadth 200mm; depth 60mm

Special Collection

Provenance

Purchased from Tesseract, Box 151, Hastings-on-Hudson, New York 10706, USA from 16/07/1997.

Inscription

‘E. Leybold’s Nachfolger
Coeln-Rhein’ (slide holder)
‘Reflexion einer Schallwelle am
weischlossenen Ende ein Höhre’ (one terquem plate)
‘Reflexion einer Schallwelle am
offenen Ende einer Höhre.’ (other terquem slide)

Description Notes

This is a dual purpose machine. Wide cast iron base has a slider trough and supports a slit aperture plate mounted with an adjustable hand crank brass drive to pulley and disk holder. To the disk holder on the opposite side of the pulley and handle can be fixed Crova’s Disc, a glass disc photographically printed with clear eccentric arcs on a black ground. Turning the handle rotates the disk and through a slit in the vertical panel allows the viewing of the harmonic motion. There are 3 crova’s discs with this group. Two were sent free by Tesseract because they were damaged, the third disk is fine. There are also two rectangular photographically printed slides showing discontinuous wave forms and labelled in German. These plates are mounted in an oxidised brass holder with a brass handle and as the holder is pulled past the slit the slide demonstrates the motion of sound waves.

Condition good (two Crova’s discs damaged); complete

References

Events