Comptes Rendus Research Articles

Foreword to the special issue of Comptes Rendus Mécanique in the memory of Roland Glowinski

Foreword to the special issue of Comptes Rendus Mécanique in the memory of Roland Glowinski

A direct proof of the non-existence of a MOL(6)

It is well known that a Latin Square of order 6 has no orthogonal mate. Many proofs are known, some of which are very short, see for instance (Betten in Unterricht 36:449–453, 1983; Beth et al. in Design theory, Bibliographisches Institut Mannheim Wien, Zürich, 1985; Tarry in Comptes Rendus Ass Franc Sci Nat 1900(2), 170–203, 1901; Stinson in J Comb Theory A 36:373–376, 1984). This paper provides a short proof of this fact which avoids a case distinction on the isomorphism types of the Latin Square. We observe that any Latin Square of order 6 falls within exactly one of three categories. Either it has two rows which form a permutation whose cycle type is three transpositions. Or it has no subsquare of order 2, or it is a single Latin Square with symmetry group the rotation group of the cube of order 24. In each case, the nonexistence of an orthogonal mate can be seen quickly.

Comment on The Cu–Pb–Zn-bearing veins of the Bou Skour deposits (Eastern Anti-Atlas, Morocco): structural control and tectonic evolution by Aabi A., et al.

This note is a comment to the article « The Cu–Pb–Zn-bearing veins of the Bou Skour deposit (Eastern Anti-Atlas, Morocco): structural control and tectonic evolution » by Aabi et al., published online on May 04, 2021, in Comptes Rendus Geoscience in Volume 353, 2021, pages 81–99 (https://doi.org/10.5802/crgeos.54). The authors’ response to this comment has also been published in Comptes Rendus Géoscience in Volume 354, 2022, pages 125–130 (https://doi.org/10.5802/crgeos.117).

Reply to comment by El Ouardi et al. on The Cu–Pb–Zn-bearing veins of the Bou Skour deposit (Eastern Anti-Atlas, Morocco): structural control and tectonic evolution

This note is a reply to the « Comment on The Cu-Pb-Zn-bearing veins of the Bou Skour deposit (Eastern Anti-Atlas, Morocco): structural control and tectonic evolution » by Hmidou El Ouardi et al., published in Comptes Rendus Géoscience in Volume 354, 2022, pages 119–123 (https://doi.org/10.5802/crgeos.115). It concerns the article « The Cu-Pb-Zn-bearing veins of the Bou Skour deposit (Eastern Anti-Atlas, Morocco): structural control and tectonic evolution » by Aabi et al., published online on May 04, 2021, in Comptes Rendus Geoscience in Volume 353, 2021, pages 81–99 (https://doi.org/10.5802/crgeos.54).

Did the first inhabitants of the Caune de l’Arago between 700,000 and 400,000 years BP have domesticated fire? Did they know how to light the fire at will?

This note is a comment to the article “Search for early traces of fire in the Caune de l’Arago at Tautavel (Eastern Pyrenees, France), combining magnetic susceptibility measurements, microscopic observations, and Raman analysis” by Deldicque et al., published online on July 29, 2021, in Comptes Rendus Géoscience in Volume 353, 2021, pages 247-264, https://doi.org/10.5802/crgeos.66. The authors’ response to this comment has also been published in Comptes Rendus Géoscience in Volume 354, 2022, pages 47-50, https://doi.org/10.5802/crgeos.114.

Traces of fire in a 560,000-year-old occupation soil at Caune de l’Arago: response to the article by Professor Henry de Lumley

This note is a reply to the comment “Did the first inhabitants of the Caune de l’Arago between 700,000 and 400,000 years BP have domesticated fire? Did they know how to light the fire at will?” by H. de Lumley, published in Comptes Rendus Géoscience in Volume 354, 2022, pages 41-45, https://doi.org/10.5802/crgeos.113. The comment in question concerns the article “Search for early traces of fire in the Caune de l’Arago at Tautavel (Eastern Pyrenees, France), combining magnetic susceptibility measurements, microscopic observations, and Raman analysis” by Deldicque et al., published online on July 29, 2021, in Comptes Rendus Géoscience in Volume 353, 2021, pages 247-264, https://doi.org/10.5802/crgeos.66.

The geometric reason for the non-existence of a MOL(6)

The problem of Euler concerning the 36 officers, (Euler, in Leonardi Euleri Opera Ser I 7:291–392, 1782), was first solved by Tarry (Comptes rendus Ass Franc Sci Nat 1 (1900) 2:170–203, 1901). Short proofs for the non-existence were given in Betten (Unterricht 36:449–453, 1983), Beth et al. (Design Theory, Bibl. Inst. Mannheim, Wien, Zürich, 1985), Stinson (J Comb Theory A 36:373–376, 1984). This problem is equivalent to the existence of a MOL(6), i. e., a pair of mutually orthogonal latin squares of order 6. Therefore in Betten (Mitt Math Ges Hamburg 39:59–76, 2019; Res Math 76:9, 2021; Algebra Geom 62:815–821, 2021) the structure of a (hypothetical) MOL(6) was studied. Now we combine the old proofs and the new studies and filter out a simple way for the proof of non-existence. The aim is not only to give still other short proofs, but to analyse the problem and reveal the geometric reason for the non-existence of a MOL(6)- and the non-solvability of Euler’s problem.

Padé Approximation and Hypergeometric Functions: A Missing Link with the Spectrum of Delay-Differential Equations

It is well known that rational approximation theory involves degenerate hyperge-ometric functions and, in particular, the Padé approximation of the exponential function is closely related to Kummer hypergeometric functions. Recently, in the context of the study of the exponential stability of the trivial solution of delay-differential equations, a new link between the degenerate hypergeometric function and the zeros distribution of the characteristic function associated with linear delay-differential equations was emphasized. Such a link allowed the characterization of a property of time-delay systems known as multiplicity-induced-dominancy (MID), which opened a new direction in designing low-complexity controllers for time-delay systems by using a partial pole placement idea. Thanks to their relations to hypergeometric functions, we explore in this paper links between the spectrum of delay-differential equations and Padé approximations of the exponential function. This note exploits and further comments recent results from [I. Boussaada, G. Mazanti and S-I. Niculescu. 2022, Comptes Rendus. Mathématique] and [I. Boussaada, G. Mazanti and S-I. Niculescu. 2022, Bulletin des Sciences Mathématiques].

The Italian Empire and the Great War by Vanda Wilcox

The Maghreb Review, Vol. 47, 1, 2022 © The Maghreb Review 2022 This publication is printed on FSC Mix paper from responsible sources BOOK REVIEWS / COMPTES RENDUS Books reviewed in The Maghreb Review can be ordered from The Maghreb Bookshop. Our catalogue is also available on our website: www.maghrebbookshop.com VANDA WILCOX, THE ITALIAN EMPIRE AND THE GREAT WAR. OXFORD UNIVERSITY PRESS, 2021. In October 1911 Italy declared war on the Ottoman Empire and mounted a massive seaborne invasion of Turkish Tripolitania and Cyrenaica across the central Mediterranean. If at that time Italy was generally seen as ‘the least of the Great Powers’, so its prime foreign policy objective seemed to be the achievement of Great Power status by taking on no less an opponent than Turkey and seizing its last remaining North African possessions. But what was expected to be a swift and simple campaign, a mere ‘military parade’, turned into a vicious and prolonged war of colonial conquest. And, as Vanda Wilcox argues in her new study of the Italian empire, the story of Italy and the First World War actually begins with the war against Ottoman Turkey in 1911, after which Italy was to experience more than a decade of conflict, ending only in 1923-4 (or up to 1932 in the case of Libya). During the Libyan war the Italians for the first time used many of the latest tools of twentieth century technology – barbed wire and machine guns, motor transport, aircraft (both airships and aeroplanes, tried and tested for reconnaissance, target-spotting, strafing and bombing) and (thanks to Guglielmo Marconi) wireless. Yet Wilcox asserts that among the obvious defects of this imperial venture into Libya were an essentially inept military machine and precarious state finances, both with serious implications for Italy’s forthcoming performance in the First World War. Intriguingly, she argues that the Italo-Turkish war of 1911-12, and the two Balkan wars of 1912-13 are integral to an understanding of how the First World War began, and also many aspects of how it was fought. She suggests that ‘it was the succession of defeats suffered by the Ottomans in North Africa and the Balkans which began the process of destabilising the precarious European balance of power’. (p.13) (Here there seems to be an echo of events that led up to the Second World War, notably the international crisis provoked by Italy’s invasion of Ethiopia in 1935.) Wilcox also suggests that for Italy the most important legacy of the Italo-Turkish war was the experience of ‘unprecedented’ cross-party mobilisation. ‘This both demonstrated the new power of the media and mass culture to shape public opinion and indicated that the process of ‘creating Italians’ was well under way. Fatally, however, the 114 CURATED BY MOHAMED BEN-MADANI experience taught that the shared causes around which Italians could coalesce were expansionism and war.’ (p.39) Here the implications for the rise of Fascism are clear. Then, because this is a contemporary book, much space has to be devoted to issues of race and Italian ‘whiteness’ in the context of the Libyan experience. Yet given Italy’s own history of repeated invasions, partitions and foreign subjection and rule, Italians tend to be defined less by physical, racial characteristics than by culture (in the broadest sense), language and religion. And in any case the similarity in appearance of many northern Libyans and southern Italians often leaves little room for active ‘racial’ discrimination, at least on grounds of physical appearance. This book offers an arresting and important thesis, which indeed suggests that this is a subject that deserves further and wider study. The Libyan side of the story is perhaps presented with less assurance than the other issues (for instance, the common religion of Turks, Berbers and Arabs, and the allimportant role of the Sanusi religious confraternity might usefully have been given more weight). Also reliance on contemporary Italian ‘historians’ such as Angelo del Boca and his following tends to distort and even falsify much of the the Italian colonial record in Libya in particular and in Africa in general. For the writers of this school can find little good at all, no merit...

Ernest Rutherford’s ambitions

One of the pioneers of radioactivity research, Rutherford feared his work would be overlooked—and changed his publishing strategies to make sure it wasn’t.

BEM-Fading regularization algorithm for Cauchy problems in 2D anisotropic heat conduction

We investigate the numerical reconstruction of the missing thermal boundary data on a part of the boundary for the steady-state heat conduction equation in anisotropic solids from the knowledge of exact or noisy Cauchy data on the remaining and accessible boundary. This inverse boundary value problem is tackled by applying and adapting to the anisotropic case the algorithm based on the fading regularization method, originally proposed by Cimetiere, Delvare, and Pons (Comptes Rendus de l’Academie des Sciences - Serie IIb - Mecanique, 328 639–644 2000), and Cimetiere, Delvare, et al. (Inverse Probl., 17 553–570 2001) for the isotropic heat conduction equation. The numerical implementation is realised for 2D homogeneous solids by using the boundary element method, whilst the numerical solution is stabilized/regularized by stopping the iterative process based on an L-curve type criterion (Hansen 1998).

Lipschitz classification of self-similar sets with overlaps

In Rao et al. (Comptes Rendus Acad Sci Paris Ser I(342):191–196, 2006), Rao–Ruan–Xi solved an open question posed by David and Semmes and gave a complete Lipschitz classification of self-similar sets on mathbb R with touching structure. In this short note, by applying a matrix rearrangeable condition introduced in Luo (J Lond Math Soc 99(2):428–446, 2019), we generalize their result onto the self-similar sets with overlapping structure.

Langevin's influence on relativity theories

A century ago, Paul Langevin [C. R. 173, 831 (1921)], through his influence, convinced the scientific community that Einstein's theories of relativity were correct and could explain the Sagnac effect. A simple note in Comptes Rendus was all it took to silence many prominent skeptical scientists. The relativity skeptics had pointed to Sagnac's experiment [C. R. 157, 1410 (1913)] with the interference of counter rotating light beams as proof that the speed of light was not the same in both directions, contrary to the key postulate in Einstein's theory. Langevin showed that the result was also explained by relativity. The rest is history, and relativity has remained a center piece of theoretical physics ever since. Langevin had been captivated by solar eclipse observations of a shifted star pattern near the sun as reported by Eddington [Report on the Relativity Theory of Gravitation (Fleetway Press, Ltd., London, 1920)]. This was taken as proof positive for Einstein's General Theory of Relativity. The case of a light beam split into two beams, which propagate in opposite directions around a circuit, has an analog in a simple thought experiment—a speed test for runners. Two runners can be timed on a running track with the runners going around the track in opposite directions. Two stop watches will display the time for each runner's return to the starting position. The arithmetic difference in time shown on each stop watch will provide the differences in speed between the two runners. If the two speeds are the same, the time difference will be zero. It would not make any sense for one of the stop watches to measure a negative time, that is, time moving into the past. In fact, the idea is absurd! However, Langevin did just that, assigned the time for light to travel in one direction as positive while the time for the light to traverse in the opposite direction as negative, moving into the past! By so doing, Langevin reproduced Sagnac's expression and declared that relativity explains Sagnac's experiment. Langevin was wrong!

Editorial to the Thematic Issue of Comptes Rendus Chimie dedicated to the Periodic Table of the Elements

Editorial to the Thematic Issue of Comptes Rendus Chimie dedicated to the Periodic Table of the Elements

Bianchi’s additional symmetries

In a 2012 note in Comptes Rendus Mathématique, the author did try to answer a question of Jean-Pierre Serre; it has recently been announced that the scope of that answer needs an adjustment, and the details of this adjustment are given in the present paper. The original question is the following. Consider the ring of integers \(\mathcal {O}\) in an imaginary quadratic number field, and the Borel–Serre compactification of the quotient of hyperbolic 3–space by \(\mathrm {SL_2}(\mathcal {O})\). Consider the map \(\alpha \) induced on homology when attaching the boundary into the Borel–Serre compactification. How can one determine the kernel of \(\alpha \) (in degree 1) ? Serre used a global topological argument and obtained the rank of the kernel of \(\alpha \). He added the question what submodule precisely this kernel is.

Just Green Enough: Urban Development and Environmental Gentrification edited by WinifredCurran and TrinaHamilton, Routledge, New York, 2018, 248 pp., hardback $208.80 (ISBN 978‐1138713796).

The Canadian Geographer / Le Géographe canadienVolume 64, Issue 2 p. e11-e12 Book Review / Comptes rendus de livres Just Green Enough: Urban Development and Environmental Gentrification edited by Curran, Winifred and Hamilton, Trina, Routledge, New York, 2018, 248 pp., hardback $208.80 (ISBN 978-1138713796). Tyler McCreary, orcid.org/0000-0001-6305-6325 Florida State UniversitySearch for more papers by this author Tyler McCreary, orcid.org/0000-0001-6305-6325 Florida State UniversitySearch for more papers by this author First published: 22 May 2020 https://doi.org/10.1111/cag.12621Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume64, Issue2Summer / été 2020Pages e11-e12 RelatedInformation

Le Maghreb Dans La Guerre, 1939–1945 par Chantal Metzger

The Maghreb Review, Vol. 45, 2, 2020 © The Maghreb Review 2020 This publication is printed on FSC Mix paper from responsible sources BOOK REVIEWS / COMPTES RENDUS Books reviewed in The Maghreb Review can be ordered from The Maghreb Bookshop. Our catalogue is also available on our website: www.maghrebbookshop.com CHANTAL METZGER, LE MAGHREB DANS LA GUERRE, 1939-1945, PARIS, ARMAND COLIN, 2018. 311 PAGES. Chantal Metzger, emerita professor of history at the Université de Lorraine (Nancy), is the authority on the Third Reich’s policy toward France's colonial empire.1 The present publication is an outgrowth of her investigations and a close-up on a key region of France’s overseas possessions during the Second World War. Given the breadth of the title and the reputation of Armand Colin as a publisher of university-level textbooks, the reader could have expected a straightforward exposé of the topic, based on the latest research. It is that undoubtedly, but there is much more. The author makes abundant use of primary sources, especially German archives where her expertise is manifest. Inquiries about France’s dependencies overseas rarely, if ever, refer to German documents. In and of itself, the source material gives this book a novel touch. Relevant French archives are also put to fruitful use. The outcome is a publication that combines the pedagogical qualities of a textbook and the features of an original piece of research normally found in a monograph. No particular thread is pursued and no overarching thesis is argued therein. The reader is provided with an informative and reliable panorama of the complex and quickly evolving situation of North Africa during the war. While the military dimension is present, the scope is wider, encompassing the political context, international relations and the living conditions of the population. The structure is classic. Part I provides a portrait of the Maghreb on the eve of the war. The Tunisian and Moroccan protectorates are presented from different perspectives, such as governance, composition of the population, socioeconomic conditions and rise of nationalism. Algeria is a settler colony divided in three départements and considered an “integral part of France”. Structural inequality between European colons and Algerians breeds blatant injustices, giving rise to deep polarization and setting the stage for a fight to the finish between colonialism and nationalism from 1954 to 1962. Turning to German and Italian designs on North Africa before 1939, the book attests to their reality 1 L’Empire colonial français dans la stratégie du Troisième Reich (1936-1945). 2 vol. Brussels, PIE Peter Lang, 2002. 496 BOOK REVIEWS / COMPTES RENDUS but points to their different nature. Mussolini’s ambitions were territorial, focusing on Tunisia. Italy nursed a grievance against French presence in the beylicate since the 1880’s. Germany's aims were economic, to wit mineral resources and raw materials. Both Rome and Berlin conducted intensive radio propaganda to convince Arab opinion of their benevolent intentions toward Arab national aspirations. Part II covers the three years from the declaration of war in 1939 to the Anglo-American landing in 1942. North Africa was mobilized and remained by and large loyal to France, despite dissatisfaction with its rule and discontent about socio-economic conditions. Quiescence may also be explained by the fact that nationalist leaders were placed under arrest at the start of the war. France’s defeat was unexpected in North Africa but it did not diminish local support, partly because the prospect of Italian tutelage was loathed and France appeared to be the lesser evil. Following the armistice, North Africa remained under the authority, albeit limited, of Vichy. Armistice Commissions were soon on the spot to pump out the economic resources the Axis Powers requisitioned. Shortages of basic necessities became the order of the day for the population. In the meantime, the French administration set about applying Vichy's National Revolution to the Maghreb. The Anglo-American landing on 8 November 1942 opened a new phase. Part III shows how meticulously it was prepared by disinformation directed at the German military and by prior contacts with French officials and dissidents in the targeted territories. The object was to avoid having to fight the sizable...

(Invited) Diamond Technology – Integration into Solid-State Breakers and Biomedical Devices

A commercial viable solid-state direct current circuit breaker with fast switching performance for the use in the 1-100kV range requires a low loss on-resistance close to commercial available mechanical breakers [1]. Diamond provides excellent semiconductor properties for those breaker applications with a material characteristics superior in high electric field breakdown strength, higher thermal conductivity, and high charge carrier mobility as compared to silicon, silicon carbide, and gallium nitride [2-4]. These properties will enable diamond electronic devices that will be more energy efficient while keeping the active area of devices to lower values, which offers a potential cost advantage in case of a better availability of large-area substrates [5,6]. Diamond diodes [7-9], diamond field effect transistors [10], and gate turn-off thyristor devices [11-13] are proposed to be the core unit in a medium voltage direct current (MVDC) solid-state circuit breaker [14,15]. A reduced energy loss in solid-state breakers by using diamond will enable a competitive placement of diamond breakers on the MVDC market with a decisive advantage of a much faster response to electrical circuit faults and more robust DC electrical energy delivery systems with >1MW capacity. The diamond-based diode and FET development focuses on devices in the 1-5kV range and the diamond thyristors cover a 15-20kV range. Higher voltages would ultimately be achieved with series circuit arrangements of the diamond devices. Diamond offers also excellent properties for applications in the biomedical sector [16]. The manufacturing of tailored biopharmaceuticals, stem cells, or human tissue is being attempted through the utilization of single-use perfusion bioreactors due to its minimal spacial and financial costs, and its ability to execute critical parallel processing methods [17,18]. However, continuous monitoring of analytes in multifaceted protein mixtures and achieving full automation of production are challenges inhibiting commercialization of tailored products to a reasonable price. Constant and instantaneous monitoring of a bioreactor both ensures flexibility with the opportunity for quick adjustments and eliminates contamination risks from manual sampling. Also, it is essential that the bioactive layer of an integrated biosensor monitoring system sustains the lifetime of the processing cycle, as well as display a shelf life compatible with standard inventory consumption. Achieving and maintaining the specific conditions necessary to produce complex bio-products requires a robust real-time monitoring with redundancy and automated control of a variety of nutrients, intermediate metabolites, and cell products within the bioreactor. Diamond biosensors exhibit low biofouling rates and show promising results in the in-situ monitoring of the bioprocess conditions for the full operation time of single-use bioreactors [19]. Operational human IL-8 antibodies have been successfully adhered to the diamond sensor surface [20]. A high antibody concentration and activity as a measure of biosensor sensitivity is obtained using a modified ELISA procedure. The results indicate a reasonable robust diamond biosensor performance suitable for in-situ applications in the complex environment of bioreactors [21]. Song, C. Peng, A.Q. Huang (2017) IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS 5(1), 278.Kalish (2007) Journal of Physics D: Applied Physics 40(20), 6467.Hiraiwa, H. Kawarada (2013) Journal of Applied Physics 114(3), 034506.Tsao et.al. (2018) Advanced Electronic Materials 4(1), 1600501.Friel et.al. (2019) Diamond and Related Materials 18, 808.Tallaire, J. Achard, F. Silva, O. Brinza, A. Gicquel (2013) Comptes Rendus Physique 14, 169.Alvearez, M. Boutchich, J. P. Kleider, T. Teraji, Y. Koide (2014) J. Phys. D: Appl. Phys. 47, 355102.Ozawa et.al. (2018) Diamond and Related Materials 85, 49.Zimmermann et.al. (2005) Diamond & Related Materials 14(3-7), 416.Huang, B. Zhang (2000) Solid-State Electronics 44, 325.Paques et.al. (2011) IEEE Electron Device Letters 32, 1421.HERLET, K. RAITHEL (1966) Solid-State Electronics 9, 1089.ADLER (1978) IEEE TRANSACTIONS ON ELECTRON DEVICES ED-25(1), 16.Shenai (2018) IEEE TRANSACTIONS ON ELECTRON DEVICES 65(10), 4216.Gu, P. Wheeler, A. Castellazzi, A.J. Watson, F. Effah (2017) Energies 10, 495.Hébert, S. Ruffinatto, P. Bergonzo (2015) Carbon for Sensing Devices, 978-3-319-08648-4, 227.Shukla, U. Gottschalk (2013) Trends in Biotechnology 31(3), 147.Bijonowski, W.M. Miller, J.A. Wertheim (2013) Current Opinion in Chemical Engineering 2(1), 32.Bixler, B. Bhushan (2012) Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 370, 2381.Navas et.al. (2018) Applied Surface Science 433, 408.Mross, T. Zimmermann, N. Winkin, M. Kraft, H. Vogt (2016) Sensors and Actuators B: Chemical 236, 937.

The birth of the research on the magnetic confinement for nuclear fusion

Abstract At their very beginning, the researches on the magnetic confinement fusion had to face up plasma instabilities. Macroscopic plasma instabilities were the first ones to be identified and they were found to be very harmful for plasma confinement. During the first years after the Atoms for Peace Meeting in 1958, the main goals of experimental and theoretical researches dealt with their suppression or control. During this period, two special types of instabilities, the localized interchange modes and the tearing modes, were discovered. French physicists and the Comptes rendus hebdomadaires des seances de l'Academie des sciences have been steadily involved into this field. It generated a huge amount of works and, in spite of these efforts, they still remain an active research topic and maybe a matter of concern. However, the achieved progress allows most physicists to believe that these instabilities are not any more a real hurdle on the way to magnetic confinement fusion.

Sur la période des maxima d’activité solaire

This is the publication of a pli cacheté (sealed letter) submitted to the French Academy of Sciences in 1918 by Jean Malburet (amateur astronomer, 1879–1955). The subject is “On the period of solar activity maxima”. If not reclaimed for 100 years, such sealed letters are opened and analysed by members of the Academy. This letter was considered sufficiently interesting to be published in Comptes rendus Geoscience, along with a descriptive comment of its contents and some of the subsequent history of the ideas put forward in that sealed contribution. In 1918, J. Malburet proposed that “triple syzygies” (alignments) of the planets Jupiter, Venus, and the Earth (with some smaller influence of Mercury) caused tides on the Sun that imposed on our star the observed periodicity (or rather quasi-periodicity) of 11 years. Thanks to contacts with the author’s grandson, two subsequent (1918 and 1925) papers were found, whereas Nicola Scafetta (pers. comm.) pointed out a 1927 criticism of the paper by H.M. Losh. The topic is still an active one today, as witnessed for example by papers by Scafetta, 2012a, Scafetta, 2012b, Scafetta, 2016). The handwritten text of the sealed letter has been typed for easier access to readers and is placed after a short analysis. French has been used throughout this as this is the language of the letter.