The result, was in Helmholtz's words, to establish beyond doubt that ordinary light consists of electrical vibrations in an all-pervading ether which possesses the properties of an insulator and of a magnetic medium.
On the theoretical side the greatest stimulus came from the publication in 1847, without knowledge of Mayer or Joule, of Helmholtz's great memoir, Ober die Erhaltung der Kraft, followed immediately (1848-1852) by the establishment of the science of thermodynamics, mainly by R.
After 1872, in addition to its regular organs, it issued Hungarian translations of several popular scientific English works, as, for instance, Darwin's Origin of Species; Huxley's Lessons in Physiology; Lubbock's Prehistoric Times; Proctor's Other Worlds than Ours; Tyndall's Heat as a Mode of Motion, &c. Versions were also made of Cotta's Geologie der Gegenwart and Helmholtz's Populcire Vorlesungen.
Viii.) further adapted the siren for more extensive use, by the addition to Dove's instrument Helmholtz's of another chest cone), i Double taming its own fixed Siren.
In works on sound it is usual to adopt Helmholtz's notation, in which the octave from bass to middle C is written c d e f g a b c'.
Helmholtz's theory of the resonator (Rayleigh, Sound, ii.
C is a constant, equal to the coefficient of viscosity in Helmholtz's theory, but less simple in Kirchhoff's theory.
Helmholtz's double siren is well calculated for the investigation of the laws of interference of sound.
The vibrograph is also well suited for the same purpose, and so in an especial manner is Helmholtz's double siren, in which, by continually turning round the upper box, a note is produced by it more or less out of tune with the note formed by the lower chest, according as the handle is moved more or less rapidly, and most audible beats ensue.
The difficulty in Helmholtz's theory is to account for the audibility of such beat tones when they are of a higher order than the first.
If we are to assume that the tones received by the ear are pure and free from partials, the loudness of the beattones would appear to show that Helmholtz's theory is not a complete account.
Sedley Taylor, Sound and Music (1882), contains a simple and excellent account of Helmholtz's theory of consonance and dissonance.
A modified form of Helmholtz's equation, due to E.
Helmholtz's contributions to physiological optics are of great importance.
There is another coefficient of absorption (K) which occurs in Helmholtz's theory of dispersion (see Dispersion).