MODERN PROBLEMS IN ACOUSTICS. 
BY 
Charles Kasson Wead. 
[Read before the Society, April 14, 1900.] 
I. In the history of Acoustics two names are preeminent, 
Chladni, the text-book writer, who united to wide knowledge 
of the subject great ingenuity and experimental skill, and 
Helmholtz, in whom there was a unique combination of 
mathematician, physiologist, physical experimenter, and 
musician. His Sensations of Tone as a physical basis for music , 
published (in German) in 1863, and the monographs summed 
up in it, contained enough in each of these four lines to make 
one famous. The book has for nearly forty years dominated 
the thoughts of most people who believe that the science of 
Acoustics has anything to teach musicians. Still it is sig¬ 
nificant thjat musicians have largely refused to recognize its 
sway, some showing crass ignorance in their comments, 
others making it clear that there is something in the appeal 
of music to the mind and heart of man that eluded his phi¬ 
losophy. Though this ancient question of the physical basis 
of music is still a problem, there is time here to note but two 
points, and these have reference rather to the mode of attack 
than to the problem itself: (1) That which scholarly musi¬ 
cians of today think of as music differs to an important ex¬ 
tent from what was in Helmholtz’s mind forty years ago as 
truly, though not as widely, as it differs from mediaeval 
music; (2) materials available in recent years for the his¬ 
torical study of European and Oriental scales disclose sev¬ 
eral consciously-used principles of scale-building which could 
not result in the diatonic or harmonic scales for which Helm- 
Note. —Names in parentheses are of past or present members of the 
Society. 
( 129 ) 
