Savart's wheels

Date1870-1910

Inventory Number1997-1-0950

ClassificationSavart's Wheel

Subject

Maker French

Inventor Félix Savart 1791 - 1841

Cultural Region

Dimensions55 x 44 x 25 cm (21 5/8 x 17 5/16 x 9 13/16 in.)

Material

DescriptionThe base of this instrument is rectangular. At one end is a hole with threads in it. It was used to screw in the (missing) column supporting one or more sounding cards under the brass wheels. At the other end of the base is the supporting column for the eight equally-spaced toothed wheels (in front) and a grooved one (in the back). The toothed wheels all have isocele teeth in multiple of six (8-9-10-11-12-13-14-15): 48 for the first one in the front; 54 for the second one; 60 for the third; 66 for the fourth; 72 for the fifth; 78 for the sixth; 84 for the seventh; and 90 for the eighth and final one. The grooved wheel was used with a mechanical or later electrical machine to put the toothed wheels in a regular rotational motion.

As several other acoustical instruments in the collection, this one has an old location number inscribed on an oval paper glued to the side: 19-1-2. There is another old location number stamped on this instrument: 20-19.

In Collection(s)

Exhibit 2010--Sensations of Tone

Signedon third front wheel, stamped: illegible

Curatorial RemarksThis instrument is most likely French. There is only one stamp mark, on the third wheel from the front. It is, however, very faint and is as yet unidentified.

FunctionThis instrument was used to produce specific sounds by letting a rigid card come into contact with the rotating wheels. If the wheels rotate at a constant speed, putting two cards on separate wheels can generate different kinds of pitches. For instance, owing to the number of teeth on these wheels, the diatonic scale can be entirely reproduced. For instance, the 9/8 tone with the 1st and 2nd wheels; the 4/3 tone with the 2nd and 5th wheels; the 15/8 tone with the 1st and 8th wheels, etc.

The French physicist Félix Savart (1791-1841) devised this system of generating sound frequencies and used these toothed wheels to try to determine the upper limit of audible frequencies.