(b. Brody, Galicia [now Ukrainian S.S.R.], 23 April 1856; d. Perchtoldsdorf, near Vienna, Austria, 4 October 1920)
One of the most important meteorologists of the early twentieth century, Margules provided the first thorough, theoretical analyses of atmospheric energy processes and deeply influenced the evolution of present concepts of such processes. He studied mathematics and physics at Vienna and in 1877 joined the staff of the Zentralanstalt für Meteorologie in Vienna. From 1879 to 1880 he continued his studies at Berlin and then returned to Vienna as Privadozent in Physics. In 1882 he resigned from this post, thus terminating his career at the university. He was then reemployed by the Zentralanstalt until 1906. During this time Margules produced a small number of highly important papers in meteorology. In 1906, at the age of fifty, he retired and gave up meteorology, again concentrating on physical chemistry, apparently because of embitterment at the lack of recognition for his work. Lonely, unmarried and without close friends, he literally starved to death during the austere postwar period.
After returning to the Zentralanstalt in 1882, Margules continued to pursue physical and physical-chemical investigations in his free time. His publication dealt with electrodynamics, the physical chemistry of gasses, and hydrodynamics. Independently of Gibbs and Duhem, he developed in 1895 a formula for the relation between the partial vapor pressures and the composition of a binary liquid vapor pressures known as the Duhem-margules equation. In 1881–1882 he furnished a theoretical analysis of the rotational oscillations of viscous fluids in a cylinder.
From 1890 to 1893 Margules produced a series of papers related to meteorology that dealt with osciallation periods of the earth’s atmosphere and the solar semidiurnal barometric pressure oscillation, the universal character of which had been established by his colleague Hann. William Thomson had suggested that the magnitude of this oscillation could be explained by a resonance oscillation of the entire atmosphere. Margules substantiated this hypothesis theoretically by computing free and forced oscillations of the atmosphere on the basis of Laplace’s tidal theory. He never considered his results to be a rigorous proof, however, because of several unrealistic assumptions and the lack to a physical explanation for the semidiurnal temperature variation. Margules also investigated the oscillations of a periodically heated atmosphere, using various heating models, and gave a general classification of these motions.
While these studies still tended toward theoretical physics, Margules’ next investigations dealt in a novel manner with problems fundamental to meteorology. In 1901 he demonstrated that the kinetic energy displayed in storms was far too great to be derived from the potential energy of the pressure field. He reduced the pressure field, which meteorologists had previously regarded as an explanation for the genesis of atmospheric motions, to a mere “cog-wheel in the storm’s machinery.”
In a famous1905 paper Margules proposed a new source for the production of kinetic energy by studying models of energy transformations in the atmosphere that involved the isentropic redistribution of warm and cold air masses from a state of instability to one of stability. He showed that the realizable kinetic energy of these closed systems was the difference between the sums of internal energy and gravitational potential energy at the beginning and the and the end of the redistribution process, Margules considered this quantity, which is now called available potential energy, as the source of kinetic energy in storms. His theoretical analyses supported F. H. Bigelow’s view that the coexistence of warm and cold air masses is the precondition for the development of storms. The cyclone model subsequently developed by J. Bjerknes was based energetically largely on Margules’ work. Margules’ results formed the basis for F. M. Exner’s and A. Refsdal’s investigations and have continued to influence meteorological thought. The work of E. Lorenz is an example.
In his discussion of idealized situations in which there is a large store of available potential energy (1906), Margules demonstrated that on the rotating earth two air masses of different temperatures, separated by an inclined surface of discontinuity, can exist in equilibrium under certain conditions. He developed a formula for the slope of this surface, using methods developed by Helmholtz. Bjerknes and his group later applied Margules’ formula to their cyclone model, in which such frontal surfaces were the salient feature.
Margules considered the study of detailed observations, distributed three-dimensionally, to be of utmost importance for progress in meteorological theory. For this reason in 1895 he began to install a small network of stations around Vienna. Observations from these and nearby mountain stations allowed him to study the progression of cold and warm air masses and sudden variations in barometric pressure and wind during the passage of storms; these observations influenced his theoretical considerations and vice versa.
Margules also attempted to determine the frictional dissipation of kinetic energy and made the first estimate of the efficiency of the general circulation of the atmosphere as a thermodynamic engine. One of his last meteorological investigations, which dealt with the development of temperature inversions by descending motion and divergence, contributed to the understanding of anticyclones.
I. Original Works. Most of Margules’ papers are listed in Poggendorff, III, 870–871; IV, 960; V, 807, Many of his important publication are in Sitzungsberichte der Akademie der Wissenschaften in Wien, Math.-naturwiss. Kl., Abt. IIa: “Über die Bestimmung des Reibungs- und Gleitcoefficienten aus ebenen Bewegungen einer Flüssigkeit,” 83 (1881), 588–602; “Die Rotationsschwingungen flüssiger Zylinder,” 85 (1882), 343–368; “Über die Schwingungen periodisch erwärmter Luft,” 99 (1890), 204–227, English trans. by C. Abbe in “The Mechanics of the Earth’s Atmosphere,” 2nd collection, Smithsonian Miscellaneous Collection,34 (1893), 296–318;; “Luftbewegungen in einer rotierenden Sphäroidscale,” pt. 1, 101 (1892), 597–626; pt. 2, 102 (1893), 11–56; pt. 3, ibid., 1369–1421; and “Über die Zusammensetzung der gesättigten Dämpfe von Mischungen,” 104 (1895), 1243–1278.
See also Über den Arbeitswert einer Luftdruckverteilung und über die Erhaltungder Durckunterschiede,” in Denkshriften der Akademie der Wissenschaften, Math.- naturwises. Kl., 73 (1901), 329–345, English trans. by C. Abbe in “The Mechanics of the Earth’s atmosphere,” 3rd collection, Smithsonian Miscellaneous Collection,51 (1910), 501–532; Über die Beziehung zwischen Barometerschwankungen und Kontinuitätsgleichung,” in Boltzmann-Festschrift (Leipzig, 1904), 585–589; “Über die Engergie der Stüteme,” in Jahubuch der Zentralanstalt für Meteorologie und Erdmagnetismus,40 (1905), 1–26, English trans, by C. Abbe in “The Mechanics of the Earth’s atmosphere,” 3rd collection (see above), 533–595; “Über die Änderung des vertikalen Temperaturgefälles durch Zusammendrückung oder Ausbreitung einer Luftmasse,” in Meteorologishche Zeitschrift,23 (1906), 241–244; “UÜber die Temperaturschichtung in stationär bewegter und in ruhender Luft,” ibid. (1906), 243–254; and “Zur Sturmtheorie,” ibid., 23 (1906), 481–497.
II. Secondary Literatute. Some information on Margules’ personal life may be found in the obituaries in Meteorologische Zeitschrift,37 (1920), 322–324; and Das Wetter,37 (1920), 161–165. See also F. Knoll, ed., Österreichische Naturforscher, Ärzte und Techniker (Vienna, 1957), 40–42.