PH I LI PS TECHNICAL R·EVI EW ------------ VOLUME 40,1982, No. 5 ---------'------- Gilles Holst, pioneer of industrial research in the Netherlands H. B. G. Casimir ·1 On the occasion of the twentieth anniversary of the Eindhoven University of Technology in 1976 it was decided to institute an annual 'Holst Lecture'. Its organization was made possible by a donation from the Philips Company. The central theme of each lecture was to be the development of the technological sciences in interaction with the natural sciences and mathe- matics on the one hand, and with their industrial applications and the consequences of such applications on the other. The choice of name pays tribute to the memory of Prof. Dr G. Holst who, as a distinguished physicist in the Netherlands and founder of Philips Research Laboratories, did much to promote that interaction. Since then there have been five Holst Lectures. The speakers at the first four lectures were Prof. Alexander King, Prof. C. Freeman, Prof. Dr C. F. Frh. van Weizsäcker and Prof. Kevin Lynch. The main subject ofthefifth Holst Lecture was Holst himself, and the organizers "H(ere fortunate infinding the best imaginable speaker on this subject - Prof. Dr H. B. G. Casimir, from 1942 a member of Hoist's staf! and later one of his successors. I The opportunity to publish Professor Casimir's paper here (with a veryfew minor changes, mainly his own), gives the editors particular pleasure in as much as Holst was in fact the founder of Philips Technical Review. Who was Gilles Holst? Those who knew him, who helium, of superconductivity; Lorentz is associated in felt his influence, who had the privilege to work under our minds with electrons, with the Lorentz force, the his leadership, will never forget him. But their num- Lorentz transformation, the Lorentz contraction; ber is beginning to diminish. Anyone undertaking an Zeeman with the Zeeman effect. In textbooks you will "in-depth study of the history of scientific research in probably look in vain for the name of Holst: although the Netherlands, and in particular of the history of the work he published did play a role in the general industrial scientific research, will undoubtedly come progress of science, it cannot be counted among the across his name, but there are few engaged in such permanent pillars of modern physics. And yet, he was studies. It is good to use the occasion of this annual one of the great men of his generation. I am therefore lecture to perpetuate his name, which is in danger of happy to have this opportunity today to try and becoming to many no more than a name. The name of recreate for you the figure of Holst. Van der Waals immediately conjures up the equation of state, the condensation of gases, the Van der Waals Gilles Holst was born at Haarlem on 20th March forces between molecules; when Kamerlingh Onnes is 1886. His father, Casper Hendrik Holst, was the man- mentioned we think of low temperatures, of liquid ager of the Conrad Shipyards. Holst went through higher secondary education in Haarlem, took his Prof. Dr H. B. G. Casimir wasformerly a member of the Board of Management of N. V. Phllips' Gloeilampenfabrieken and headed leaving certificate in 1903 and then worked for six scientific research in the Philips group of companies worldwide, months in his father's shipyard and six months with· 122 H. B. G. CASIMIR Philips tech. Rev. 40, No. 5 the firm of Willem Smit. During this initiation into completely new field of research. It led as early as the business world he must already have realized that 1911 to the discovery of what still constitutes one of in the long run mechanical engineering was not going the most remarkable phenomena of the solid state: to satisfy him. 'I didn't like cast iron' was later one of superconductivity. It think it is worth while looking a his obiter dicta, and this at first sight perhaps rather little more closely at the role that Holst played in this mysterious remark comprises a great deal of Helst's sensational discovery. way of thinking and working. What irked him was Electrical-resistance measurements at liquid-helium that, although you can make splendid calculations temperatures (1-4 K) formed part of the research pro- for mechanical structures, in the final analysis you gramme Kamerlingh Onnes had embarked upon. When had to allow for a substantial safety margin because preliminary measurements on platinum revealed that, not enough was known about the properties of the contrary to all expectations at the time, a further construction material, particularly of cast iron. It decrease of resistance took place upon cooling to was this very problem of understanding and techno- liquid-helium temperatures, Kamerlingh Onnes pub- logically controlling the properties of materials that lished a theoretical argument providing a plausible was later to become a guiding principle of Helst's explanation for a very rapid decrease. The measure- work. ments were prepared and carried out by Dr Dorsman In 1904 he went to Zürich to study at the Techno- and Holst, who were given the job of measuring the logical University there, initially electrical engineer- resistance of mercury. At least, it is reasonable to ing. Was there still too much cast iron in electrical assume that that is what happened. At the end of the engineering? After two and a half years and an inter- first publication [11, which did establish a rapid drop mediate examination he switched to mathematics and in resistance upon cooling but no complete disappear- physics. In 1908 he received the degree of geprûfter ance of resistance, that is to say no superconductivity, Fachlehrer, qualifying him as a teacher in higher Kamerlingh Onnes wrote: education. At all events, fundamental physics inter- 'I gratefully record my indebtedness to Dr. C. Dors- ested him - and mathematics, too, for that matter. man for his intelligent assistance during the whole of Marcel Grossmann (1878-1936) was from 1907 a pro- this investigation, and to Mr. G. Holst, who con- fessor of geometry at Zürich. He was a good friend of ducted the measurements with the Wheatstone-bridge Einstein's and his scientific adviser in matters of in- with much care.' variant multidimensional geometry. I seem to recall These or similar acknowledgements were repeated Holst telling me that he had attended Grossmartn's . in subsequent publications, in particular those that lectures on 'Ausdehnungslehre' as propounded by describe superconductivity. Two years later Kamer- Grassmann (1809-1877). After graduating, Holst lingh Onnes concluded a publication [21 with the spent about a year as an assistant of Professor H. F. words: Weber [*1. He then returned to the Netherlands, was 'Having completed the series H of my experiments for a short time an assistant of Siertsema at Delft and with liquid helium I wish to express my thank to Mr. at the beginning of 1910 joined Kamerlingh Onnes as G. Holst, assistant at the Physical Laboratory, for the an assistant at Leiden. devotion with which he has helped me, and to Mr. It is perhaps amusing to mention in passing that G. J. Flim, chief of the technical department of the Einstein in 1900received the same degree as Holst did cryogenic laboratory, and Mr. O. Kesselring, glass- later, but that Weber did not want him as an assistant. blower to the laboratory, for their important help in One might wonder whether Einstein would have been the arrangement of the experiments and manufac- the most suitable man to lead a practical physics course turing of the apparatus.' for up-and-coming engineers, but Einstein himself ap- Much later, in a confidential document in which he pears to have been somewhat affronted by this rejec- recommends Holst for appointment to membership tion and even went so far as to complain that Weber of the Netherlands Royal Academy of Sciences (Holst was intriguing against him. Even more remarkable'is in fact became a member in 1926) Kamerlingh Onnes that Einstein at the time applied for a job with ... wrote: Kamerlingh Onnes, on a carelessly handwritten post- 'Of his work at Leiden it should be mentioned that he card, reply postage paid. Kamerlingh Onnes did not cooperated in the discovery of the superconductivity use it; 1 don't suppose he took the application of metals and in the further research on supercon- seriously. ductivity. ' The Leiden cryogenic laboratory occupied a unique What are we to conclude from all this? It seems position in 1910. In 1908 Kamerlingh Onnes had suc- clear to me that Holst carried out the resistance meas- ceeded in liquefying helium, thereby opening up a urements and that he was thus the first to observe Philips tech. Rev. 40, No. 5 GILLES HOLST 123 superconductivity. May we then regard him as a co- 'I believe that ..... rather underestimates the merits discoverer of superconductivity? 'Of course not,' of the great KOH - evidently a codename for Heike Kamerlingh Onnes would probably have replied. Kamerlingh Onnes - because he is certainly a man 'I provided the liquid helium,' he might have argued, who plays a big role, even if it is often only the role of 'I set the task of measuring the resistance of mercury bath superintendent.' - a measurement which, it is true, was not so easy, This is a characterization that Kamerlingh Onnes given the special circumstances, but which could would not himself have appreciated. In the same letter nevertheless be performed with known methods. A Holst writes that he is going to Eindhoven on 1st competent experimenter, performing the task I had January. With a dash of bravura he writes: set him, was bound to discover superconductivity.