Scheibler, Johann Heinrich
Inventor of a tonometer, by which every note of the exactly equally tempered scale was produced. He was born at Montjoie, near Aix-laChapelle, and was by trade a silk manufacturer at Crefeld, where he spent most of his life, dying there in 1837 or 1838. He began experimenting with jewsharps about 1812, and then with the monochord in search of a better system of tuning. The result was the invention of an instrument with fifty-two chords. This instrument is now lost, but a later one of fifty-six chords is still preserved. In the Journal of the Society of Arts, March 5, 1880, the test which proved each fork of this instrument correct within a tenth of the double vibVation is recorded. This invention and system of tuning is explained in Scheibler's pamphlet, Der physikalische und musikalisches Tonmesser, published in 1834. After Scheibler's death his works were collected and published by Schmuller in 1838 as Heinrich Scheibler's Schriften uber musikalische und physikalische Tonmessung. It was at Scheibler's suggestion that the Congress of Physicists, held at Stuttgart in 1834, fixed the pitch of a at four hundred forty vibrations, which is called the Stuttgart pitch. According to his method a is two hundred twenty vibrations.