produced by normal pressure, as far as the bass clef F. The F below the bass clef is the true lowest note, the other seven semitones descending to the B flat being obtained by holes and keys in the long joint and bell.  These extra notes are not overblown.  The fundamental notes are extended as in the oboes and flutes by overflowing to another octave, and afterward to the twelfth.  In modern instruments yet higher notes, by the contrivance of small harmonic holes and cross fingerings, can be secured.  Long notes, scales, arpeggios, are all practicable on this serviceable instrument, and in full harmony with clarinets, or oboes and horns, it forms part of a rich and beautiful combination.  There is a very telling quality in the upper notes of the bassoon of which composers have made use.  Structurally, a bassoon consists of several pieces, the wing, butt, long joints, and bell, and when fitted together, they form a hollow cone of about eight feet long, the air column tapering in diameter from three-sixteenths of an inch at the reed to one and three-quarter inches at the bell end.

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 in the orchestra there is a lower contrabass sarrusophone made in C, the compass of which is from the double bass octave B flat to the higher G in the bass clef.