520 



NATURE S TEACHINGS. 



is, in fact, another octave ; and then a few other notes, the 

 truth of which depends on the ear of the player. 



Now, all these notes are obtained by means of the lips, 

 which set the column of air vibrating, and divide it into 

 harmonics. The apparently complicated bugle-calls of the 

 army are nearly all formed from four notes only, i.e. (taking 

 C as the tonic) CGCEG. 



The Trombone, which is shown on the right hand of the 

 illustration, has the advantage of being lengthened at will, 

 and thus giving the performer a fresh tonic, and consequently 



TRACHEA OF SWAN. 



TROMBONE . 



another series of harmonics. Yalved and keyed instruments 

 have a similar advantage, the one acting by lengthening, and 

 the other by shortening, the column of air. The former 

 is infinitely the better plan, as it sets more harmonics vibrating, 

 and consequently gives a greater richness of tone. 



A familiar example of this is to be found in the Ophicleide 

 and Euphonium. The former is eight feet in total length, and 

 alters its tonic by eleven keys, which shorten the column of 

 air. The latter is of the same length, but, by the employment 

 of valves, can be made sixteen feet in length. Consequently 

 the euphonium has practically killed the ophicleide, just as the 

 ophicleide killed the serpent. The cornet-a-pistons, the brass 

 contra-basso, the flugel horn, the tenor sax-horn, &c, are all 

 constructed on the same principle. 



