358 DR. KffiNIG'S RESEARCHES ON 



fandamental and the three perturbed harmouics has been filled by the 

 addition of three true harmonics. This disk is the first in this research 

 which gives a real timbre, though it is a peculiar one. It preserves, 

 however, a unitary character, even when the slit is tilted in either 

 direction. The 24 waves in this disk all rake forward like the teeth of 

 a circular saw, but with luultiform ripples upon them. The quality of 

 tone becomes more crisp when the slit is tilted so as to slope across the 

 teeth, and more smooth when in the reverse direction. 



The fifth disk, which is larger, has 40 waves at its edge. These are 

 cut with curves of all sorts, taken haphazard from various combinations 

 of pure harmonics in all sorts of proportions and varieties, no two being 

 alike, there maxima and minima of the separate waves being neither 

 isochronous nor of equal amplitude. This disk gives an entirely unmu- 

 sical eftect, amid which a fundamental tone is heard, accompanied by a 

 sort of rattling sound made up of intermittent and barely recognizable 

 tones. 



The sixth disk is derived from the preceding by selecting eight only 

 of the waves, and repeating them five times around the perii)hery. In 

 this case each set of eight acts as a single long curve, giving beats, 

 with a slow rotation and a low tone (accompanied always by the rattling 

 mixture of higher tones) when the speed is increased. 



The seventh disk was constructed by taking 24 waves of perfect sin- 

 usoidal form, and superposing upon them a series of small ripples of 

 miscellaneous shapes and irregular sizes, but without essentially depart- 

 ing from the main outline. This disk gives a timbre in which nothing 

 can be separated from the fundamental tone, either with vertical or 

 tilted slit. 



The eighth and last disk consists of another set of 24 perfect waves, 

 from the sides of which irregular ripples have been carved away by 

 hand, with the file, leaving however the summits and the deepest 

 parts of the hollows untouched, so that the maxima and minima are 

 isochronous and of equal amplitude. This disk gives also a definite 

 timbre of its own, a little raucous in quality, but still distinctly having 

 a musical unity about it. 



We have every reason therefore to conclude that the ear will recog- 

 nize as possessing true musical quality, as a timbre, combinations in 

 which the constituents of the sound vary in their relative intensity and 

 phase from wave to wave. 



What, then, is a timbre? Dr. Koenig would be the first to recognize 

 that these last experiments, though of deepest interest, do not afibrd a 

 final answer to the question. We may not yet be in a position to frame 

 a new definition as to what constitutes a timbre, but we may at least 

 conclude that, wiienever that definition can be framed, it will at least 

 include several varieties, including the non-periodic kinds with multi- 

 form waves, as well as those that are truly periodic with uniform waves. 

 We must not on that account however, rush to the conclusion that the 



