lower end of the slide. When the slide is closed,
the instrument is at its highest pitch, and as the column of air is
lengthened by drawing the slide out, the pitch is lowered. By this
contrivance a complete chromatic scale can be obtained, and as the
determination of the notes it produces is by ear, we have in it the
only wind instrument that can compare in accuracy with stringed
instruments. The player holds a cross bar between the two lengths of
the instrument, which enables him to lengthen or shorten the slide at
pleasure, and in the bass trombone, as the stretch would be too great
for the length of a man's arm, a jointed handle is attached to the
cross bar. The player has seven positions, each a semitone apart for
elongation, and each note has its own system of harmonics, but in
practice he only occasionally goes beyond the fifth. The present
trombones are the alto in E flat descending to A in the seventh
position; the tenor in B flat descending to E; the bass in F
descending to B, and a higher bass in G descending to C sharp. Wagner,
who has made several important innovations in writing for bass brass
instruments, requires an octave bass trombone in B flat; an octave
lower than the tenor one, in the "Nibelungen." The fundamental tones
of the trombone are called "pedal" notes. They are difficult to get
and less valuable than harmonics because, in all wind instruments,
notes produced by overblowing are richer than the fundamental notes in
tone quality. Valve trombones do not, however, find favor, the defects
of intonation being more prominent than in shorter instruments. But
playing with wide bore tubas and their kindred is not advantageous to
this noble instrument.

The serpent has been already mentioned as the bass of the obsolete
zinken or wooden cornets, straight or curved, with cupped mouthpiece.
It gained its serpentine form from the facility given thereby to the
player to cover the six holes with his fingers. In course of time keys
were added to it, and when changed into a bassoon shape its name
changed to the Russian bass horn or basson Russe. A Parisian
instrument maker, Halary, in 1817, made this a complete instrument,
after the manner of the keyed bugle of Halliday, and producing it in
brass called it the ophicleide, from two Greek words meaning serpent
and keys--keyed serpent--although it was more like a keyed bass bugle.
The wooden serpent has gone out of use in military bands within
recollection, the