Helmholtz Sentence Examples

Later in the same year he became assistant to Helmholtz in the physical laboratory of the Berlin Institute.

During the three years he held this position he carried out researches on the contact of elastic solids, hardness, evaporation and the electric discharge in gases, the last earning him the special commendation of Helmholtz.

Imagining that this would interest Hertz and be successfully attacked by him, Helmholtz specially drew his attention to it, and promised him the assistance of the Institute if he decided to work on the subject; but Hertz did not take it up seriously at that time, because he could not think of any procedure likely to prove effective.

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.

Lenard and Helmholtz, contain many biographical details, together with statements of the scope and significance of his investigations.

Timbre itself is, as Helmholtz shows, a kind of harmony felt but not heard.

For cells in which the electromotive force varies with temperature, the full equation given by Gibbs and Helmholtz has also been confirmed experimentally.

By this reasoning Helmholtz showed how to obtain an expression for the work done.

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.

Helmholtz in 1871 is the ` foundation of the important doctrine of the microscopic limit.

Lord Rayleigh has recorded that he was himself convinced by Fraunhofer's reasoning at a date antecedent to the writings of Helmholtz and Abbe.

If 2R be the diameter of the objectglass and D the distance of the object, the angle subtended by AP is E/D, and the angular resolving power is given by X/2 D sin a = X/2 R (3) This method of derivation (substantially due to Helmholtz) makes it obvious that there is no essential difference of principle between the two cases, although the results are conveniently stated in different forms. In the case of the telescope we have to deal with a linear measure of aperture and an angular limit of resolution, whereas in the case of the microscope the limit of resolution is linear, and it is expressed in terms of angular aperture.

In order to minimize the heating action of the light, it might be submitted to a preliminary prismatic analysis before it reaches the slit of the spectrometer, after the manner of Helmholtz.

It was the concepts derived from the experimental methods of Harvey, Lavoisier, Liebig, Claude Bernard, Helmholtz, Darwin, Pasteur, Lister and others which, directly or indirectly, trained the eyes of clinicians to observe more closely and accurately; and not of clinicians only, but also of pathologists, such as Matthew Baillie, Cruveilhier, Rokitansky, Bright, Virchowto name but a few of those who, with (as must be admitted) new facilities for necropsies, began to pile upon us discoveries in morbid anatomy and histology.

Helmholtz, of the efflux of a jet between two edges A and A 1 in an infinite wall, is obtained by the symmetrical duplication of the above, with n = 1, b = o, a' = - oo, as in fig.

The function J = E-94,, has been called the " free energy " of the substance by Helmholtz, and 90 the " bound energy."

Helmholtz in his " Ophthalmometer " has employed Clausen's principle, but arranges the plates so that both move symmetrically in opposite directions with respect to the telescope axis.

Should Clausen's micrometer be employed as an astronomical instrument, it would be well to adopt the improvement of Helmholtz.

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'.

It may, however, be stated here that certain experiments of Helmholtz appear to show that the epoch of the harmonics has not much effect on the quality.

According to Helmholtz, the ear probably contains within it a series of resonators, with small intervals between the periods of the successive members, while the series extends over the whole range of audible pitch.

He used a spherical Helmholtz resonator resounding to the tone to be measured.

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.

Smith, though recognizing the unpleasantness of beats, could not accept Sauveur's theory, and, indeed, it received no acceptance till it was rediscovered by Helmholtz, to whose investigations, recorded in his Sensations of Tone, we owe its satisfactory establishment.

Thus Helmholtz explains the jarring and braying which are sometimes heard in bass voices.

The reader is referred to the full discussion by Helmholtz.

We may illustrate the first method by taking a case discussed by Helmholtz (Sensations of Tone, app. xvi.) where the two sources are reeds or pipes blown from the same wind-chest.

The second is termed by Helmholtz the difference tone, and the third the summation tone.

The conditions assumed in this investigation are probably nearly realized in a harmonium and in a double siren of the form used by Helmholtz, and in these cases there can be no doubt that actual objective tones are produced, for they may be detected by the aid of resonators of the frequency of the tone sought for.

There is not much difficulty in detecting the difference tone by a resonator if it is held, say, close to the reeds of a harmonium, and Helmholtz succeeded in detecting the summation tone by the aid of a resonator.

But there is no doubt that it is very difficult to detect the summation tone by the ear, and many workers have doubted the possibility, notwithstanding the evidence of such an observer as Helmholtz.

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.

Koenig, Quelques experiences d'acoustique (1882) describes apparatus and experiments, intended to show, in opposition to Helmholtz, that beats coalesce into tones, and also that the quality of a note is affected by alteration of phase of one of its component overtones relative to the phase of the fundamental.

Lamb, The Dynamical Theory of Sound (1910), is intended as a stepping-stone to the study of-the writings of Helmholtz and Rayleigh.

Other voltaic standards of electromotive force are in use, such as the Weston cadmium cell, the Helmholtz calomel cell, and the standard Daniell cell.

Among psychologists Helmholtz, Mach, Brentano, Hering, Delboeuf, were all more or less against him.

It is unnecessary here to rake among the ashes of this prolonged dispute, but it may be noted that Helmholtz, who, in his lecture on "Ice and Glaciers," adopted Thomson's theory, afterwards added in an appendix that he had come to the conclusion that Tyndall had "assigned the essential and principal cause of glacier motion in referring it to fracture and regelation" (1865).

The Liberty party had previously, in November 1847, nominated 3 See Helmholtz, op. cit.

Helmholtz and Lord Rayleigh are founded on this relation.

The validity of the recilirocal theorems of Helmholtz and Lord Rayleigh, already referred to, is not affected by frictional forces of the kind here considered.

Helmholtz brought to bear upon the subject not only the most profound mathematical attainments, but immense experimental skill, and his work in connexion with this subject is classical.

He confirmed an opinion already previously expressed by Helmholtz and by Henry, that in some circumstances this discharge is oscillatory in nature, consisting of an alternating electric current of high frequency.

Berzelius early in the 19th century had advanced the hypothesis that chemical combination was due to electric attractions between the electric charges carried by chemical atoms. The notion, however, that electricity is atomic in structure was definitely put forward by Hermann von Helmholtz in a well-known Faraday lecture.

Delicate in early life, Helmholtz became by habit a student, and his father at the same time directed his thoughts to natural phenomena.

Helmholtz's contributions to physiological optics are of great importance.

Fitzgerald was the first to attempt to measure the length of electric waves; Helmholtz put the problem into the hands of his favourite pupil, Heinrich Hertz, and the latter finally gave an experimental demonstration of electromagnetic waves, the "Hertzian waves," on which wireless telegraphy depends, and the velocity of which is the same as that of light.

The life of Helmholtz was uneventful in the usual sense.

Helmholtz was a man of simple but refined tastes, of noble carriage and somewhat austere manner.

When Pasteur in 1857 showed that the lactic fermentation depends on the presence of an organism, it was already known from the researches of Schwann (1837) and Helmholtz (1843) that fermentation and putrefaction are intimately connected with the presence of organisms derived from the air, and that the preservation of putrescible substances depends on this principle.

Various experiments by Schwann, Helmholtz, Schultz, Schroeder, Dusch and others led to the refutation, step by step, of the belief that the more minute organisms, and particularly bacteria, arose de novo in the special cases quoted.

The garden towards Unter den Linden is adorned by a bronze statue of Helmholtz; the marble statues of Wilhelm and Alexander von Humboldt, which were formerly placed on either side of the gate, have been removed to the adjacent garden.

There is another coefficient of absorption (K) which occurs in Helmholtz's theory of dispersion (see Dispersion).

In the interval between his election and the assumption of his duties at Baltimore, he studied physics under Helmholtz at Berlin, and carried out a well-known research on the effect of an electrically charged body in motion, showing it to give rise to a magnetic field.

Helmholtz successfully applied this behaviour of ice under pressure to the explanation of many properties of the substance.

The other scientist whose works he studied deeply was Helmholtz, in particular reading Helmholtz '1860 results on the acoustic resonator.

Helmholtz thought him the one of all his pupils who had penetrated farthest into his own circle of scientific thought, and looked to him with the greatest confidence for the further extension and development of his work.

Helmholtz also wrote on philosophical and aesthetic problems. His position was that of an empiricist, denying the doctrine of innate ideas and holding that all knowledge is founded on experience, hereditarily transmitted or acquired.