ID:
203
Maker's Name:
Max Kohl, Chemnitz
Where made:
Germany
c1910
Dimensions:
45 × 30 × 92 cm
An acoustic interferometer using a 'manometric flame' as detector. Coal-gas is fed to a pinhole burner via a chamber closed by a membrane upon which the acoustic signal is incident. Motion of the membrane causes the flame to wax and wane. Even when this occurs rapidly, there is an average 'flaring' which is easily seen. A rotating mirror was used to visualise more rapid variations. The interferometer can be filled with different gasses to determine the velocity of sound in each.
92*45*30
N.R.H.
Book reference:
G.L'E. Turner Nineteenth Century Scientific Instruments, Uni. of California Press, Berkeley (1983), pg 144
