Apparatus for testing the appreciation of difference in musical pitch. After Galton, by Camb. Scient. lnstr. Co. See a figure of this device in the <link href="http://www.sil.si.edu/digitalcollections/trade-literature/scientific-instruments/files/51682/imagepages/image117.htm">1899 catalog</link> of the Cambridge Scientific Instruments Co, p.109, no. 392. Apparatus for testing the appreciation of difference in musical pitch. After Galton, by Camb. Scient. lnstr. Co.
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