century,
from the post-horn, by the application of the newly invented pistons of
Stoelzel and Bluemel patented in 1815. It was introduced into Great
Britain and France about 1830. There were at first only two pistons--for
a whole tone and for a half tone--from which there naturally resulted
gaps in the chromatic scale of the instrument. The use of a combination
of pistons (see BOMBARDON and VALVES) fails to give acoustically correct
intervals, because the length of tubing thus thrown open is not of the
theoretical length required to produce the interval. A tube about 4 ft.
long, such as that of the B[flat] cornet, needs an additional length of
about 3 in. to lower the pitch a semitone; but, if this cornet has
already been lowered one tone to the key of A[flat], the length of tube
has increased some 6 in., and the 3-in. semitone piston no longer adds
sufficient tubing to produce a semitone of correct intonation. To the
performer falls the task of concealing the shortcomings of his
instrument, and he therefore corrects the intonation by varying the lip
tension. At first the cornet was supplied with a great many crooks for
A, A[flat], G, F, E, E[flat] and D, but from the explanation now given,
it will be readily understood that they were found unpractical for valve
instruments, and all but the first two mentioned have been abandoned.
The history of the cornet is a record of the endeavours of successive
musical instrument makers to overcome this inherent defect in
construction. The most ingenious and successful of these improvements
are the following:--(1) The _six-valve-independent system_[18] of
Adolphe Sax, designed about 1850, by which a separate valve was used for
each position, thus obviating the necessity of using combinations of
pistons. This theoretically perfect system unfortunately introduced
great difficulties in practice, the valves being made _ascending_
instead of _descending_, and each piston cutting off a definite length
of wind-way from the open tube, instead of adding to it. The system was
eventually abandoned. (2) The _Besson Registre_ giving eight independent
positions, afterwards modified as the (3) _Besson compensating system
transpositeur_, patented in England in 1859, which was considered so
successful that the idea was extensively used by other makers. (4) The
_Boosey automatic compensating piston_, invented by D. J. Blaikley, and
patented in 1878, a very ingenious device whereby when two or more
pi