Music and the Making of Modern Science

228 Chapter 14

The ear is greatly superior in this respect to any other nervous apparatus. It is eminently the organ

for small intervals of time, and has been long used as such by astronomers. 26

This striking comparison shows how far he took comparisons between hearing and seeing

to illuminate their shared domains of space and time.

In an essay entitled “ The Recent Progress of the Theory of Vision ” (1868), Helmholtz

drew attention to another fundamental contrast: vision blends several incoming colors into

one perceived hue, whereas hearing always leaves several notes distinctly separate : “ The

eye cannot tell the difference if we substitute orange for red and yellow; but if we hear

the notes C and E sounded at the same time, we cannot put D instead of them, without

entirely changing the impression upon the ear. ... The practiced musician is able to catch

the separate notes of the various instruments among the complicated harmonies of an entire

orchestra, but the optician cannot directly ascertain the composition of light by means of

AB

Figure 14.10

(a) Helmholtz ’ s double siren, from Tonempfindungen (1863). (b) A double siren built by Sauerwald, ca. 1870

(Collection of Historical Scientific Instruments, Harvard University).