1884—Frederick Niecks, in *A Concise Dictionary of Musical Terms,* provides the following

“Trombone. A brass wind instrument with a slide, by which means it can extend its compass downwards, and produce all the chromatic notes within this compass….Besides the notes comprised in the compass…each of the three trombones has four so-called ‘pedal-notes:’ those of the alto and bass trombones, however, are bad and not easily practicable; and of those of the tenor trombone (B-flat, A, A-flat, G), only the first three are good, the fourth being difficult to produce….Three is the usual number of trombones employed in the orchestra. But the bass trombone is becoming more and more rare, and instead of it a second tenor trombone is frequently employed. In France we find even three tenor trombones. Besides the slide trombones there are also valve trombones, which, however, are inferior with regard to tone” (Niecks 246).**