The bending back at the butt joint is pierced in one piece of wood,
and the prolongation of the double tube is usually stopped by a
flattened oval cork, but in some modern bassoons this is replaced by a
properly curved tube. The height is thus reduced to a little over four
feet, and the holes, assisted by the artifice of piercing them
obliquely, are brought within reach of the fingers. The crook, in the
end of which the reed is inserted, is about twelve inches long, and is
adjusted to the shorter branch.

The contra-bassoon is an octave lower than the bassoon, which implies
that it should go down to the double B flat, two octaves below that in
the bass clef, but it is customary to do without the lowest as well as
the highest notes of this instrument. It is rarely used, but should
not be dispensed with. Messrs. Mahillon, of Brussels, produce a reed
contra-bass of metal, intended to replace the contra-bassoon of wood,
but probably more with the view of completing the military band than
for orchestral use. It is a conical brass tube of large proportions,
with seventeen lateral holes of wide diameter and in geometrical
relation, so that for each sound one key only is required. The compass
of this contra-bass lies between D in the double bass octave and the
lower F of the treble clef.

The sarrusophones of French invention are a complete family, made in
brass and with conical tubes pierced according to geometric relation,
so that the sarrusophone is more equal than the oboe it copies and is
intended, at least for military music, to replace. Being on a larger
scale, the sarrusophones are louder than the corresponding instruments
of the oboe family. There are six sarrusophones, from the sopranino in
E flat to the contra-bass in B flat; and to replace the contra-bassoon