PRINGSHEIM, ERNST

(b. Breslau, Germany [now Wroclaw, Poland], 11 July 1859; d, Breslau, 28 June 1917)

theoretical and experimental physics.

Pringsheim was the son of Siegmund Pringsheim, a merchant and lord of a manor, and Anna Guradze. After attending the Magdalenengymnasium and the Johannesgymnasium, leaving the latter at Easter 1877, he studied mathematics for three semesters at Heidelberg and from 6 November 1878 to 9 August 1879 at Breslau, then physics and mathematics at Berlin from the autumn of 1879. He received the Ph.D. under Helmholtz on 3 July 1882 and qualified as lecturer by habilitation in physics at the University of Berlin on 5 January 1886. He was given the title of professor on 30 October 1896 and on 28 August 1905 was appointed full professor of theoretical physics at the University of Breslau, where his close collaborator Otto Lummer had preceded him six months earlier.

Pringsheim’s first lecture at Berlin (1886) was “Mechanische Wärmetheorie und kinetische Theorie der Gase.“In the winter of 1886-1887 he discussed “Thermodynamik elektrischer Vorgänge,“a topic connected with R. Claudius’ earlier studies as well as with Planck’s investigations nine years later. From 1889-1890 to 1905, he delivered nearly every year a one-hour experimental lecture on “Physic der Sonnet“; a book on the subject, containing twelve lectures, appeared in 1910. Pringsheim often connected solar physics with a lecture entitled “Einführung in die physikalische Chemie” His lectures from 1897-1898 to 1904 covered alternately “Interferenz and Polarization des Lichtes” and astrophysics.

Despite his later appointment in theoretical physics at Breslau, Pringsheim’s scientific production was largely experimental. At Berlin it was characterized by a period of research done alone and in experimental cooperation with Lummer from 1896. Pringsheim’s doctoral dissertation of 1882 ultimately determined the direction of his research, heat and light radiation.

In 1881 he had replaced the lenses of the spectrometer with hollow specula and thus had made more accurate measurements of wavelengths in the infrared with the diffraction grating. He was the first to develop the radiometer into a useful instrument for measuring infrared radiation. In the following years Pringsheim had not yet come to specialize in radiation but dealt, among other things, with chemical effects of light on hydrochloric acid gas. He also cooperated with the philologist E. Schwa of Jena to investigate the French accent phonometrically and with the lawyer Otto Gradenwitz of Köinigsberg to reconstruct old palimpsests by photography.

In physics, at the beginning of the 1890’s Pringsheim studied the limits of the validity of Kirchhoff’s law. He argued that it should apply only in the case of pure temperature radiation, as Kirchhoff had stated, and not, for example, to the radiation in Geissler’s tube or in a flame (because of chemical reactions). This view led to a dispute with Friedrich Paschen, who stated that gases may also radiate when stimulated by temperature alone. The entire question, in which Robert von Helmholtz, the son of Hermann von Helmholtz, and Willem Henri Julius of Utrecht had earlier been interested, to a certain degree contributed to recongnition of the limits of the law in connection with the role of line spectra. Pringsheim denied that line spectra of a flame could be included in Kirchhoff’s law, because they would be caused by chemical influences, but it is known today that he went too far. Kirchhoff’s law again interested Pringsheim in 1900 and 1901, when he gave a new simple theoretical proof of it that did not presume the complete blackbody, completely diathermanous substances, and completely reflecting walls. He was attacked for that proof by David Hilbert in 1912.

Pringsheim’s period of cooperation with Lummer began toward the end of the nineteenth century. First they treated the experimental determination of the ratio (k) of the specific heats for various gases, researches that had begun in the 1880’s In 1896 they turned to investigations of heat radiation. Continuing Wilhelm Wien’s work at the Physikalisch-Technische Reichsanstalt at Berlin, Pringsheim assisted Lummer in implementing Kirchhoff’s concept of the blackbody By this new means they began to verify the law of Joseph Stefan and Ludwig Boltzmann for the temperature dependence of total radiated energy. In 1900 they recognized that the small systematic deviations of their observations from the theoretical law were due to an insufficient connection of the thermoelectric temperature scale with the scale of the thermoelectric (in 1907 and in the 1960’s the scale had to be corrected again); Stefan’s law was thus verified. Pringsheim and Lummer then measured the spectral distribution of the radiation energy with the aid of the cylindrical blackbody.

Although in 1899 they stated a variability of the exponential constant of Wien’s equation with the wavelength and although they discovered even a slight curvature of the isochromatics in contradiction to that equation, it was not until September 1900 that Pringsheim and Lummer published a paper stating the “invalidity of the Wien-Planck spectral equation” on these grounds. Such negative statements were the main stimuli for Planck to seek a new radiation expression. Eugen Jahnke’s equation

E=C’T⁵(λT)^-µ e^-c’/(λT)v,

in which Lummer and Pringsheim proposed µ= 4 and v = 1.3, was soon superseded by Planck’s law, although the equation for µ = 4.5 and v = 1 (Max Thiesen) remained experimentally in competition with Planck’s for about ten years. In 1899 Pringsheim and Lummer—reversing the question—utilized Planck’s new law, specifically the so-called Wien’s limit of it (with the new constants,) to develop three methods for measuring high temperatures (up to 2,300°K). They did so by applying Stefan’s law, Wien’s T⁵ law, and spectrophotometry (founded by Paschen and H. Wanner) of the “black iscohromatics” as they called that by Lummer and Pringsheim in 1899, proved experatures. In 1903 Lummer and Pringsheim defined a “strahlungstheoretische Temperaturskala,” that is an absolute temperature scale of radiation theory. Attacking Heinrich Rubens’ determination of the temperatur of Welsbach light in 1905, they provided a discrimination between “true “ and “black” temperature.

At Breslau, Pringsheim established a six-term course in theoretical physics in 1906. His delivery was clear and animated by humor. He had sought to return to his native town. Breslau, since 1895, and for much of his life he was a member of the Schlesische Gesellschaft für vaterlandische Cultur. As early as 1879 he read a paper on his geomagnetic measurements before this society, and later he was its secretary and also its president.

BIBLIOGRAPHY

I. Original Works. The Staatsbibliothek Preussischer Kulturbesitz, Berlin-Dahlem, has the following letters by Pringsheim: one to Kultusminister Julius Robert Bosse (15 June 1895); 4 to Heinrich Kayser, Bonn (1 June 1894, 29 June 1913, 26 July 1913, 19 Aug. 1913 [written from England]); 2 to Max Iklé (27 July 1905, 11 Dec. 1906); one postcard to Iklé (4 Feb. 1915); and 2 to Ludwig Darmstaedter (7 June 1903, 13 June 1903). One letter dated 24 Oct. 1900, signed by Pringsheim and Lummer, is in the Bibliothek des Deutschen Museums, Munich. The University of Breslau has personal documents from 1878-1879, a portrait, a curriculum vita written by Pringsheim on 3 Nov. 1905, and notes in the minutes of university senate from 1903.

Published works by Pringsheim include “Über das Radiometer,” in Annalen der Physik, 254 (1883), 1-32, his doctoral dissertation; “Eine Wellenleängenmessung im ultrarothen Sonnenspectrum,” ibid., 32-34; “Über die chemische Wirkung des Lichts auf Chlorknallgas,” in Verhandlungen der Physikalischen Gesellschaft Zu Berlin, 4 (1886), 64-65, and 6 (1888), 23, and Annalen der Physik, 268 (1887), 384-428; “Eine neue Anwendung des Telephons zur Messung elektrischer Widerstände,” in Verhandlungen der Physikalischen Gesellschaft zu Berlin, 5 (1887), 80–82; “Das labile Gleichgewicht der Atome,” in Zeitschrift für physikalische Chemie, 3 (1889), 145-158; “Der franzÖsische Accent (eine phonometrische Unter-suchung),” in Archiv für das Studium der neueren Sprachen und Litteraturen, 85 (1890), 203-268, written with E. Schwan; “Argandlampe für Spectralbeobachtungen,” in Annalen der Physik, 281 (1892) 426-427; “Das Kirch-hoff’sche Gesetz und die Strahlung der Gase,” ibid., 428-458, and 285 (1893), 347-365; “Bemerkungcn zu Hrn. Paschen’s Abhandlung Über die Emission erhitzter Gase,” ibid, 287 (1894), 441-447; “Über die Leitung der Elektricität durch heisse Gase,” ibid , 291 (1895), 507-512; “Nachruf an Franz Schulz-Berge,” in Verhandlungen der Physikalischen Gesellschaft zu Berlin, 13 (1895), 53-55; and “Photographische Reconstruction von Palimpsesten,” ibid., 58-60, written with O. Gradenwitz.

Later works are “Die Strahlungsgesetze und Hire Anwendungen,” in Naturwissenschaftliche Rundschau, 15 (1900), 1-3, 17 19; “Sur l’émission des gaz,” trans, by E. Rothé, in Rapports présentés au Congrès international de physique réuni à Paris en 1900 (Paris, 1900), II , 100-132; “Einfache Herleitung des Kirchhoff’schen Gesetzes,” in Verhandlungen der Deutschen Physikalischen Gesellschaft, 3 (1901), 81-84; “Über die Gesetze der schwarzen Strahlung nach gemeinschaftlich mit O. Lummer ausgeführten Versuchen (Vorträge und Diskussionen von der 72. Naturforscherversammlung zu Aachen 16.-22.9.1900),” in Physikalische Zeitschrift, 2 (1901), 154-155, also in Ver-handlungen der Gesellsehaft Deutscher Naturforscher und Änzte, 73 Versammlung in Hamburg (1901), Abt. Physik, 27-30; “Ober Temperaturbestimmungen mit Hülfe der Strahlungsgesetze (nach gemeinsamen Untersucluingen mit Herrn O. Lummer),” in Verhandlungen der Gesellsehaft Deutsehen Naturforscher unt Ärzte, 73 . Versammlung in Hamburg (1901), pt. 2, 31 36; “Künstliche Chromo-sphäre,” in Vorlesungen der Deutsehen Physikalischen Gesellsehaft, 7 (1905), 14-15; Vorlesungen über die Physik der Sonne (Leipzig-Berlin, 1910); “Zur Theorie der Lumineszenz,” in Physikalische Zeitschrift, 14 (1913), 129-131; “Bemerkungen zur der Abhandlung des Herrn Hilbert: ‘Begründung der elementaren Strahlungstheorie,’ “ibid,., 589-591; and “Über Herrn Hilberts axiomatische Darstellung der elementaren Strahlungstheorie,” ibid, 847 850.

Other works are listed in Poggendorff, IV (1904), 1194-1195; V (1926), 1006. The British Museum Catalogue of Printed Books credits Ernst Pringsheim with Studien zur heliotropen Stimmung und Präsentationszeit (Breslau-Halle, 1909); this work is, however, by the botanist Ernst Georg Pringsheim.

Papers published with Otto Lummer include “Neue Bestimmung des Verhältnisses der beiden specifischen Wärmen,” in Verhandlungen der Physikalischen Gesellschaft zu Berlin, 6 (1888), 136-140; “Die Strahlung eines” schwarzen Körpers’ zwischen 100 und 1300°C,” in Annalen der Physik, 299 (1897), 395-410; “Bestimmung des Verhältnisses (k) der speeilischen Wärmen einiger Gase, “ in Annalen der Physik, 300 (1898), 555-583, trans, as “A Determination of the Ratio (k) of the Specific Heats at Constant Pressure and at Constant Volume for Air, Oxygen, Carbon-Dioxide, and Hydrogen, “ in Smithsonian Contributions to Knowledge, 29, no. 1126 (1903), 1–29; “Veriheilung der Energie im Spektrum des schwarzen Körpers, “ in Zeitschrift für Instrumentenkunde, 19 (1899), 214-215; “Die Vertheilung der Energie im Spectrum des schwarzen Körpers, “ in Verhandlungen der Deutschen Physikalischen Gesetlschaft 1 (1899), 23 41; “Notiz zu unserer Arbeit: Über die Strahlung eines “schwarzen’ Körpers zwischen 100°C und 1300°C, “ In Annalen der Physik, 308 (1900), 159-160; “Energicverthcilung im Spektrum des schwarzen Körpers, “ in Zeitschrift für Instrumentenkunde, 20 (1900), 148-149; and “Über die Strahlung des schwarzen Körpers für lange Wellen, “ in Verhandlungen der Deutschen Physikalischen Gesellschaft, 2 (1900), 163-180.

See also “Kritisches zur schwarzen Strahlung” in Annalen der Physik, 311 (1901), 192-210; “Temperatur-bestimmung hochcrhitzter Körper (Glühlampe etc.) auf bolomeirischem und pholomcirischcm Wege, “ in Verhandlungen der Deutschen Physikalischen Gesellschaft, 3 (1901), 36-46; “Temperaturbestimmung mit Hilfe der Strahlungsgesetze” in Physikalischen Zeitschrift, 3 (1902), 97-100; “Zur Temperaiurbcstimmung der Flammen, “ ibid., 233-235; “Die strahlungstheoretische Temperalurskala und ihre Vcrwirklichung bis 2300°abs., “ in Verhandlungen der Deutschen Physikalischen Gesellschaft, 5 (1903), 3-13; “Zur anomalen Dispersion der Gase, “ in Physikalische Zeitschrift, 4 (1903), 430; “Ober das Emissionsvermögen des Auerstrumpfes, “ ibid., 7 (1906), 89-92; “Bemerkungen zu der Abhandlung von H. Rubens: Über die Temperatur des Auerstrumpfes, “ ibid., 189-190; and “Oberdie Jeans-Lorentzsche Strahlungsformel” ibid., 9 (1908), 449-450.

With Eugen Jahnke and Otto Lummer, Pringsheim published “Kritisches zur Herleitung der Wien’schen Spectralgleichung, “ in Annalen der Physik, 309 (1901), 225-230.

II. Secondary Literature. The most reliable—and almost the only—biography is the obituary by Clemens Schaefcr, in Funfundneunzigster Jahres-Bericht der Schlcsischen Gesellschaft für vaterländische Cultur. 1917, I (Breslau, 1918), 32-36. On Pringsheim’s scientific work see H. Kangro, Vorgescitichte dea Planckschen Strahlungsgesetzes. Messungen und Theoricn der spektralen Energieverteilung bis zur Begründung der Quantenhypothese (Wiesbaden, 1970), passim. See also H. Kangro, “Ultrarolstrahlung bis zur Grenze elektrisch erzeugter Wellen, Das Lebenswerk von Heinrich Rubens, I (experimenteller Beweis der elektromagnetischen Liehttheorie für das Ultrarot),” in Annals of Science, 26 (1970), 235-259.

Hans Kangro