electromagnetic tuning-fork base with mercury interruptor
Date: circa 1865
Inventory Number: 1997-1-0877
Classification: Tuning Fork
Subject:
Maker: Rudolph Koenig (1832 - 1901)
Cultural Region:
Place of Origin:
Dimensions:
15 x 57 x 18 cm (5 7/8 x 22 7/16 x 7 1/16 in.)
Bibliography:
Rudolph Koenig's Workshop of Sound: Instruments, Theories, and the Debate over Combination Tones
Rudolph Koenig (1832-1901), Hermann von Helmholtz (1821-1894) and the Birth of Modern Acoustics
Catalogue des appareils d'acoustique construits par Rudolph Koenig
Catalogue des appareils d'acoustique
DescriptionA low frequency tuning fork would have been mounted horizontally upon this rectangular wooden base. It would have been electromagnetically driven by the adjustable coil device found in the center. The current would then have been interrupted by a platinum contact running from the lower tine of the tuning fork into the small glass vessel of mercury. Both the electromagnet holder and mercury vessel move on a slider, so that they would fit with various sizes of tuning forks. The entire instrument can be leveled by means of a large, knurled brass screw found on one corner of the base. It is very similar to 1997-1-0887. The major difference is that a small length of closed-end piping has been mounted on the base's center. This too, appears to have traces of mercury in it. Its use is unknown.
As several other acoustical instruments in the collection, this one has an old location number inscribed on an oval paper glued to the base: 21-4-1. There is another old location number stamped on this instrument: 23-23.
As several other acoustical instruments in the collection, this one has an old location number inscribed on an oval paper glued to the base: 21-4-1. There is another old location number stamped on this instrument: 23-23.
Signedon base, stamped: RUDOLPH KOENIG / À PARIS
FunctionCommon in acoustical or psychological experiments of sound perception, tuning forks are used to ascertain the variation of sound pitches. A tuning fork resonates at a specific constant pitch when set vibrating by striking it against a surface or with an object (or in this case by electricity). The pitch generated by a particular tuning fork depends on the length of the two tines, with two nodes near the bend of the usually U-shaped instrument.
This instrument here was not built for producing sound per se, but rather made as an electrical interrupter. The current used to make the (missing) tuning fork vibrate was being redirected to another piece of apparatus. Thanks to the mercury vessel, the vibrating contact at the end of the lower tine cut the current at a frequency equaled to the tuning fork. By changing the tuning fork, another regular electrical interruption was generated.
The mercury interrupter, for instance, was used for electrically driving the synthesizer forks in series at a set frequency.
This instrument here was not built for producing sound per se, but rather made as an electrical interrupter. The current used to make the (missing) tuning fork vibrate was being redirected to another piece of apparatus. Thanks to the mercury vessel, the vibrating contact at the end of the lower tine cut the current at a frequency equaled to the tuning fork. By changing the tuning fork, another regular electrical interruption was generated.
The mercury interrupter, for instance, was used for electrically driving the synthesizer forks in series at a set frequency.
Curatorial RemarksAs so many of the CHSI's instruments identified with Koenig, this one is not represented as it is in the maker's trade catalogues. They were either made especially for Harvard, or modified at Harvard by a mechanic for some other specific purposes. The only image similar to this instrument is the mercury interrupter found with the Helmholtz synthesizer. Whether this one was used with our own synthesizer is difficult to tell, though it is very plausible since no such mercury interrupter is found with the synthesizer.
Primary SourcesRudolph Koenig, Catalogue des appareils d'acoustique construits par Rudolph Koenig (Paris, 1865).
Rudolph Koenig, Catalogue des appareils d'acoustique construits par Rudolph Koenig (Paris, 1889), 26, no. 56.
Rudolph Koenig, Catalogue des appareils d'acoustique construits par Rudolph Koenig (Paris, 1889), 26, no. 56.
