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HARMONIC SERIES IN

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Originally appearing in Volume V27, Page 876 of the 1911 Encyclopedia Britannica.
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HARMONIC See also:SERIES IN C See also:ea- _:aac 12 3 4 5 6 7 8 9 10 II121314 15 16 Although the valves of See also:brass See also:wind See also:instruments vary in See also:form and detail according to the makers, the See also:general principles governing their See also:action are the same for all types. The See also:piston placed on some See also:branch of the See also:main See also:tube must be so constructed that on being de-pressed it closes the natural windways through the main See also:bore and opens others into the additional piston length. The piston seated on a See also:spring instantly regains its normal position when the See also:finger is removed. After the actual shape and construction of the See also:valve and its See also:box had been successfully evolved, it was the See also:boring and disposition of the windways which engaged the See also:attention of makers, whose See also:object was to avoid complexity and See also:sharp angles and turns in the tubing. The See also:pitch of all tubes is determined by the length of the See also:column of See also:air set in vibration therein. Any variation in the length of this column of air produces a proportional variation in the pitch of the See also:instrument. When the piston is depressed, there-fore, a See also:partition See also:wall is removed and the column of air within the additional length of tubing representing a definite See also:interval is added to the main column, so that the length of the See also:sound See also:wave is proportionally increased whether the column is vibrating as a whole (when it gives the fundamental or first See also:note of the series) or whether it has been induced to See also:divide into equal portions in which sound waves of equal length are simultaneously generated. The See also:numbers under the notes of the harmonic series represent the See also:aliquot parts into which the column of air must divide in See also:order to produce the harmonics. The length of tubing attached to each valve is there-fore calculated on the basis of the length of the main column, to give for the first piston a See also:tone, for the second a semitone, for the third a tone and a See also:half, and for the See also:fourth two tones. In order to illustrate the working of the pistons, we will take as an example the See also:bombardon or See also:bass See also:tuba in E5. Depressing the second piston lowers the pitch of the instrument to D, giving it the harmonic series proper to that See also:key; the third harmonic, which on the open tube would be B5, now becomes A; the fifth harmonic, which was G, is now F#, and so on. The first piston on being de-pressed similarly transforms the E5 bombardon into an instrument in D5, a tone See also:lower; the third piston lowering the pitch 1-i tones changes the key to C.

So far the intonation of the notes produced by means of the pistons is as accurate as that of the harmonics. The See also:

variations in the length of the column of air correspond to the positions of the slide on the See also:trombone, the first position being that of the instrument with all valves in their normal position. The use of the three pistons in turn gives the second, third and fourth positions. In order to obtain a See also:complete See also:chromatic See also:compass there must be seven positions or different lengths of tubing available, as on the trombone, each having its proper harmonic series. On valve instruments the three other positions are obtained by means of combinations of pistons; the fifth position consists of a See also:combination of pistons 2 and 3 (z and i tones), which would transpose our bombardon into the key of B; the See also:sixth position consists of a combined use of pistons i and 3, producing a drop in pitch of 21 tones from E5 to B5. In the seventh position all three pistons come into See also:play simultaneously, lowering the pitch three tones. The intonation of the notes obtained in positions 5, 6, 7 is not so faultless as that of notes from the other positions, for the following See also:reason:—On the bombardon in E5 piston I lower,: the pitch one tone to D5; in the sixth position, when pistons I and 3 are used simultaneously, the third piston is no longer attached to a bombardon in E5, on which it would produce the effect of C, but to one in D5, on which it lowers the pitch to B5; it is clear, therefore, that the supplementary tubing will not be quite See also:long enough to give the correct intonation, and that the B5 obtained as the 2nd harmonic in the sixth position will be a little too sharp, a defect which the performer corrects as best he can with his See also:lip. The exact See also:differences in length can be found from the table of ratios given by See also:Victor Mahillon in La Trompette, son histoire, sa theorie, sa construction (See also:Brussels and See also:London, 1907), p. 38. This inherent defect of the valve See also:system was understood and explained a few years after the invention of valves by Gottfried See also:Weber,' and the See also:record of the successive endeavours of brass instrument makers to overcome this defect without unduly complicating the mechanism or adding greatly to the See also:weight of the instruments constitutes the See also:history of valve instruments. The accredited inventor and patentee of valves applied to musical instruments was Heinrich Stolzel 2 of Pless in See also:Silesia in 1815. The See also:credit, however, is really due to Blumel,' also a Silesian, who sold his rights to Stolzel.

' See also:

Caecilia (See also:Mainz, 1835), xvii. 89–91. 2 See See also:Captain G. B. Bierey in Allg. musik. Ztg. (See also:Leipzig, 1815), p. 309, and idem for patent 1817, p. 814. 2 Ibid. 1818, p. 531.

The first valves made by Stolzel worked in large square brass boxes and consisted of square blocks of solid brass through which the windways were bored in the same See also:

horizontal See also:plane. A See also:trumpet having two valves of this make is preserved in the museum of the Brussels See also:Conservatoire (No. 1310 in See also:catalogue). In 1825 Stolzel had improved upon this See also:primitive valve, making it tubular and calling it Schub-Ventil: its action was lighter and more rapid than that of the See also:original valve. See also:Charles See also:Sax of Brussels took up the manufacture of these valves and applied them to the See also:cornet with two pistons. The See also:scale of instruments with only two pistons had several gaps, and could not be strictly termed chromatic. In order to complete the scale, C. A. See also:Muller of Mainz constructed a trumpet in the See also:early 'thirties which not only had three valves, but also tuning-slides for all three additional lengths of tubing 4 and key crooks, for which corresponding piston lengths could be inserted. This was, therefore, the first See also:attempt at See also:compensation, for which the See also:honour is due to See also:Germany. The early improvements and modifications of Stolzel's invention may be briefly 2 summed up as follows: In 1824 See also:John See also:Shaw, of See also:Glossop, invented a system of valves known as transverse spring slides, both ascending and descending, i.e. respectively having pistons which cut off certain lengths of tubing, thereby raising the pitch, or pistons adding certain lengths, and lowering the pitch thereby. These transverse slides were afterwards improved by Schott in 1830, and became known as the Wiener Venlil, which had an enormous success on the See also:continent of See also:Europe, and were applied to all kinds of brass instruments.

In 1827 Blumel invented the rotary valve or See also:

cylinder action known as Dreh or cylinder Ventil, a system still in use in Germany and See also:Austria, and preferred to piston systems by many. In 1833 J. G. See also:Moritz (who was associated with See also:Wieprecht, inventor of the See also:batyphone and bass tuba) made the large pistons of generous See also:diameter known as Berliner Pumpen. In 1835 John Shaw patented a variation of the rotary valve, known as patent See also:lever. In 1839 Perinet of See also:Paris invented the most See also:modern form of valve, called by his name, similar to the Schub-Ventil and Berliner Pumpen, but of a diameter between the two. In 1851 and 1852 Dr J. P. See also:Oates made his equilateral valves adopted by See also:Antoine See also:Courtois for his' cornets; the same See also:clever acoustician invented a piston with four straight windways, afterwards patented by A. Sax of Paris. Various attempts to improve the windways and get rid of angularities were made by Gustave Besson in 1851, 1854 and 1855, when a system was devised having the same bore throughout the windways. This decided improvement forms the basis of the See also:present system of the same See also:firm.

Until now efforts had mainly been directed towards the improvement of the technical construction of valves and windways. The first attempt since Miiller's (which appears to have passed unnoticed in See also:

France and See also:England) to remedy by compensation the inherent defect of the valve system when pistons are used in combination was made in 1850, when Adolphe Sax devised a system of six pistons, one for each position, in which it was impossible to use any two pistons in combination: this system was ascending instead of descending. Gustave Besson's registre in 1856–57 followed, providing a large horizontal piston, which, by connecting other duplicate lengths of tubing of the proper theoretical length, gave eight See also:independent positions. In 1858 G. Besson and See also:Girardin produced the transpositeur, in which two extra pistons when depressed automatically lengthened the slides of the three usual pistons to the required length for combination. In 1859 came the first See also:suggestion for automatic compensation made by Charles Mandel in his See also:book on the See also:Instrumentation of Military Bands, p. 39. It does not appear that he put his suggestion into practice or patented it. In this ingenious system the valves were so constructed that when two or three pistons were used simultaneously the length of tubing thrown open was automatically adjusted to the correct theoretical length required. The same ingenious principle, elaborated and admirably carried out in practice, was patented by D. J. Blaikley in 1878.

The working of his See also:

device differs from the action of See also:ordinary valves only when the pistons are used in combination. The exact theoretical length is then obtained by bringing into use extra compensating lengths of tubing corresponding to the difference between the piston length for a semitone, a tone and one and a half tones on the open tube and on the tube already lengthened by means of one of the other pistons. The value of this invention, enhanced by the See also:advantage of leaving the fingering unaltered, is more especially appreciated on the large brass instru ments, in which correction of faulty intonation by means of the lips is more difficult to accomplish satisfactorily than on the smaller instruments. A similar device was patented in France in 1881 by Sudre. Victor Mahillon, who had been for some years at See also:work on similar lines, did not patent his invention till 1886, when his piston 4 Gottfried Weber, op. cit. p. 98. 6 See also:Fuller accounts maybe derived from Captain C. R. See also:Day, Descriptive Catalogue of Musical Instruments (London, 1891), pp. 182 seq.; Victor Mahillon, Catalogue descriptif, vol. i. 2nd ed. pp. 282 seq.; and from the pages of the Allg. musik.

Ztg. (Leipzig) and Caecilia (Mainz). regulateur was introduced : this first device was not automatic, and was shortly afterwards improved and patented as the automatic regulating pistons. A later valuable development in the history of valve systems is the enharmonic, invented by Messrs Besson & Co., in which they have perfected and simplified the principle of independent positions tried in the registre of the fifties. In the enharmonic valve system each position has its independent length of tubing theoretically accurate, which comes into play as the valves are depressed, and there is besides a tuning slide for the open notes. Finally, there is an improvement in a different direction to he chronicled, unconnected with compensation, in Rudall See also:

Carte & Co.'s system (Klussmann's patent) of conical bore throughout, the open tube and the valve slides, which by means of ingeniously combined See also:joints and slides preserve the tone without loss of air. This system has been applied to all valve instruments, and has been found to produce a remarkable improvement in the timbre. (K.

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