Trombone History Update

Added several new entries to the Alto Trombone Timeline, including Stössel (Germany, 1736), Eisel (Germany, 1738), Koch (Germany, 1802), Kastner (Germany, 1840), and the trombone article from the 1888 Encyclopaedia Britannica (Scotland, 1888). Also expanded the Daniel Speer entry (Germany, 1697). Like many, many other sources, these seem to add to the preponderance of evidence in favor of a “small” alto trombone pitched in the E-flat orbit.