168 



SCIENCE 



[N. S. Vol. XXIX. No. 735 



Boehm was trying to solve. He is the 

 author of many papers, which appeared in 

 the Annalen der Physik, and in various 

 scientific and musical journals. One of his 

 papers, published in 1879, is entitled: "Is 

 the dogma of the effect of the material 

 out of which a wind-instrument is made, 

 upon the tone of the same, a fable?" 

 Schafhautl quotes at leng-th a sarcastic 

 statement which begins by saying: 



A fable, the more remarkable since it is always 

 discussed, is that the material of which a wind- 

 instrument is made, has an influence upon the 

 material of the same; that this is not so rests 

 upon incontrovertible acoustical laws, about which 

 there should be absolutely no more discussion. 



Schafhautl then says: 



ITrom the student of nature, such an oracular 

 ■speech in the name of science would certainly 

 -win a laugh. 



He proposes to allow nature to speak for 

 herself upon this interesting question. He 

 then describes with great detail how he 

 had made seven cavalry trumpets with in- 

 ternal dimensions all exactly alike ; of thick 

 brass, thin brass, lead, gypsum, and three 

 of paper of different thicknesses ; they were 

 placed side by side on a convenient stand, 

 and were blown by a most skillful profes- 

 sional trumpeter. He says: 



What a diflference in the tone quality! The 

 most brilliant tone was given by the trumpet of 

 brass 0.85 mm. thick. The tone of the trumpet of 

 lead was heavy and dull, while the tone of the 

 paper trumpets was papery and excited general 

 laughter. 



He describes many other experiments and 

 opinions about reed instruments, violins, 

 flutes, organs, the human voice, etc. The 

 study of this work led the writer to repeat 

 some of Sehafhautl's experiments and to 

 try others with organ pipes, the results of 

 which will be given in some detail. 



For a model an open organ pipe of wood 

 was chosen, of the style usually supplied 

 by Koenig for acoustical experiments. 

 This pipe gives the tone 62 = 192 com- 



plete vibrations— this is violin G, below 

 middle C ; the pipe is 5.8 cm. wide, 7 cm. 

 deep, 78 cm. long and has walls 1 cm. thick. 

 Four pipes having exactly the same in- 

 ternal dimensions as this wood pipe were 

 made of common sheet zinc, the metal being 

 about 0.5 mm. thick. Upon blowing one of 

 the zinc pipes, the unexpected result was 

 obtained that its pitch is more than two 

 semi-tones of the musical scale lower than 

 that of the wood pipe of the same dimen- 

 sions; its pitch was found to be 164, and 

 that of the other zinc pipes was nearly the 

 same. The pipes are always blown on a 

 windchest, under moderate pressure — 2^ to 

 3J inches by the water gauge — which is 

 automatically controlled. 



While the zinc pipe is clearly sounding 

 its fundamental tone, if it is very lightly 

 touched on opposite sides by the thumb and 

 finger, it immediately speaks the first over- 

 tone very clearly with no perceptible ad- 

 mixture of the fundamental ; upon removal 

 of the fingers the sound returns to the fun- 

 damental. The overtone thus obtained is 

 not harmonic, its frequency being 2.06 

 times that of the fundamental; however, 

 the pitch of both the fundamental and the 

 overtone can be varied several vibrations 

 per second by grasping the pipe in the hand 

 and varying the pressure of the grasp. 



If the pipe is firmly grasped in both 

 hands, just above the mouth, it speaks a 

 mixture of the fundamental and the second 

 partial, just mentioned and also a third 

 partial whose frequency is 2.66 times that 

 of the fundamental. ' By increasing the 

 pressure of the hands on the outside of the 

 pipe, the first and second partials become 

 weaker, while the third becomes stronger 

 till it is the real tone of the pipe; it is 

 approximately the tone Bb, a fourth above 

 the octave of the fundamental. These re- 

 sults are so conspicuous as to be almost 

 startling, caused by the unmusical sound 

 of the inharmonic partials ; the tone quality 



