One Century of Physics through a Popular Textbook: Ganot’s Treatise of Physics Françoise Khantine - Langlois Laboratoire Interdisciplinaire de Recherches en Didactique et Histoire des Sciences et des Techniques (LIRDHIST), Université Claude Bernard Lyon 1, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex Francoise.langlois @ univ-lyon1.fr Abstract In 1852, teaching was deeply modified in France and a larger place was given to scientific teaching. Consequently, numerous physics textbooks were edited. Among them, the "Traité de Physique", by Adolphe Ganot, got a prominent place. Though the author did not hold any academic position, his book was translated in numerous foreign languages and was used worldwide for physics teaching. Its still remains a reference for people interested in physics apparatus. Regularly republished for 80 years, this manual was the first to exhibit some characteristics of our present textbooks and facilitated the propagation of the new theories. In this article are reported the main innovative features of this textbook and the reasons why it became so popular. Keywords: Physics, textbooks, history of Sciences, Ganot 0n 19 May 1853 we can read in the newspaper "les Débats" this article written by Foucault Mr. Ganot offered to the Academy a small elementary treatise on Experimental Physics. We think we have to assist the good intentions of the author by announcing the second edition of a charming book simply written and without any other claim than coming as directly as possible to the intellect of the reader. M Ganot made extensive use of the help that can be drawn from the woodcut, and we can see, when opening his book at random, that he has been pleased to represent the devices in action. Only a pretentious person may take offence at the satisfaction given to the curiosity of distinguished minds, so let the troublesome people murmur against alleged abuses of funny physics or rather against diffusion of knowledge, and let loudly proclaim the importance of the high services offered to Science by the publication of illustrated books such as the excellent treatise on physics given by Mr. Ganot. When writing these words, the famous physicist  probably never imagined that the Nobel price winners Emilio Segre  and Robert Millikan , the engineer Arthur Krebs  or the Russian writer Ivan Turgenev [5 ] would quote “Ganot's physics” in their writings. In 1904, a critic still wrote “Ganot’s Treatise of physics revised by M Maneuvrier (..) is well known to our readers: it has been already used as a guide in the study of physics by many generations of students.” . He could not predict either that this textbook would be used to teach physics from Japan to Brazil, via Spain and England until the mid-twentieth century  . Who was Adolphe Ganot? What made the popularity of this textbook, its longevity and the importance of its dissemination? These are the questions which we try to answer. The “Grand Larousse of the nineteenth century” dictionary  only mentions: "Adolphe Ganot, French physicist, born in Rochefort in 1804. He devoted himself to teaching mathematics and physics and became renowned through two classic books that obtained a great success. They are entitled "Elementary Treatise of Experimental and Applied Physics and Meteorology" (...) ... and " Purely Experimental Physics Course". Pierre Binjamin (sic) Adolphe Ganot was born on 13 Floreal An XII (1804) at Rochefort, Charente Maritime, and died in Paris in 1887. His family was wealthy and educated: his father was “contrôleur des contributions”(tax inspector), and his older brother was a teacher. A graduate in Arts and in Science, as usual at that time, he taught mathematics for two years at the Royal College of Bourbon-Vendée (today Lycée Edouard Herriot at La Roche-sur-Yon) while preparing for “agrégation”. Health concerns prevented him from competing and poor relations with his father led him to leave his native area . He arrived in Paris in 1835 and taught physics in a private school founded by the chemist Alexander Baudrimont, then he opened its own school. These schools trained chemists for the industry and agriculture and prepared pupils for the "Baccalauréat"of Science . Initially, Ganot wrote his lectures for his students. As we will see later, the evolution of science education would give him the opportunity to publish them. He would then work on that all his life long. Indeed, as he reminds the reader in 1882, in the 18th edition of the treatise, the last edition he published by himself, he was the author-publisher of his books for 30 years, during which 204,000 copies of the treatise and 51,000 of the course were printed. We can argue the importance of these prints through the fact that these books can be easily found in antique bookshops. These books are often annotated and blotted, which indicates they were actually used by their owners who were fond of them, as shown by an ex-libris on the front page of a 11th edition copy acquired by an American citizen: " My old school-book corresponding to this having been destroyed by the Great Chicago Fire in 1871, I take pleasure in replacing it by this volume which I discovered in a second-hand store this 10th day of Sept. a.d. 1875 ; H.J. Birch. " In 1882 , Ganot sold to Hachette “his property and all his equipment” including the drawings of the 18th edition (woodblocks and pictures) for the important sum of 40,000 francs. George Maneuvrier  became in charge of updating the manual which would be repeatedly published in France until 1931. On the other hand, the sale agreement with Hachette mentions that translations were published in German, Dutch, Spanish, Russian, English. Well-known scientists made these translations, for example Edmund Atkinson, a student of Würtz’s and translator of Helmholtz, for the English edition. They were also published widely and regularly updated, following the French editions. Apart from these official translations, translations into Turkish, Polish and Swedish are available. How did Ganot work? Since the Treatise does not include any preface explaining the motivation and philosophy of the author, there is no easy answer to this question. We can only find the inspiration behind his work: in several places in the text, there are references to treatises of specialists such as the "Treatise of static electricity in 2 vols." by Mascart, the "Elementary treatise on the electric battery" by Alfred Niaudet, the "Treatise of Meteorology" by Becquerel or communications to the Académie des Sciences. One can imagine Ganot visiting this institution, located near his home, and reading every newly- published scientific paper. Certainly Ganot never did any research of his own, because his books never cite any personal work, unlike those of his competitors Drion and Fernet, for example . Finally, it should be noted that Ganot had strictly limited his work to a treatise on physics; although he presented himself as a mathematics teacher, he did not write anything in this field, nor on chemistry, though this science was in full development at that time. Ganot had no academic credentials, but a teaching experience that allowed him to write a really efficient book for the students. In the early nineteenth century, textbooks were written either by the scientists who were working at the time, such as Becquerel or Pouillet, or by teachers or inspectors who studied at the Ecole Normale Superieure. In 1852 a reform in secondary education, ,  including the creation of a special science section with new programs, allowed Adolphe Ganot to take the opportunity of publishing the first edition of the ‘Elementary Treatise of experimental and applied physics’. Nice prints and typography as well as various levels of reading The book stands above all the previous ones by the presence "of 360 beautiful woodcuts interspersed throughout the text." Ganot was the first to have thought of an extensive use of a recent wood engraving technique, developed in the eighteenth century and popularized around 1830. This technique, which was one of the motors of the growth of edition in the nineteenth century, allows to insert figures into the text instead of grouping them on a few sheets folded up at the end of the book. The reading was thus greatly facilitated as shown in Figures 1 and 2 below, concerning capillarity and extracted either from Despretz’ textbook (1842)  (the meniscus is at number 57) or Ganot’s Treatise. All the authors will immediately take up this process but the mention "engravings interspersed throughout the text” remained present at the beginning of textbooks for a long time. While the title pages in Becquerel’s  or Pouillet’s  textbooks only announced that they were "adopted for teaching in the Royal Colleges", Ganot’s states: "for use in education institutions" but also "for those candidates who apply for a rank of the faculties and for various state examinations". It is thus addressed directly to students by offering them the possibility of multiple reading levels since a notice explains that "paragraphs and chapters marked with an asterisk (*) are not included in the new curriculum, but they are in the curricula of medical schools and science faculties. Readers who are not familiar with the algebraic calculation will omit everything printed in small characters. " The second technical originality of the Treatise is the presence of many resolved problems. Adolphe Ganot provides a set of exercises with their solutions as soon as the 1854 edition. Some of these exercises are included in the text with their detailed solutions, and at the end of the book, one find a compendium, expanded from one edition to the next, of the examination questions given by the Paris Faculty; later, this part will be completed with the subjects of provincial faculties. The "general guidance for solving a physics problem", which appears in the 12th edition, is particularly interesting. The physics problems are presented as "real mathematics problems, but in which it is a physical law that binds the known quantities to the unknown" and a long text explains how to use the mathematical formalism of a law to determine a physics variable when knowing others. This text is still in the 21st edition in 1894, the term "mathematics" being simply replaced by the word "algebra". These problems are among the aspects of the manual praised by Millikan, who writes: "Avery was essentially an abridged Ganot, the greatest virtue of which in the abundance of excellent problems at the end of each chapter. These were largely retained in the Avery text. Before I (?) came I had worked every problem in the book, and it was these problems that gave me my real understanding and love of the subject of physics. "  All publishers would soon include the technological innovations in all manuals; from a technical point of view, Ganot’s treatise would quickly lose it originality. It would not be the same for its second feature: continuous updating of its content, which may explain the reissues and the longevity of this book. This is explicitly written in the sale contract to Hachette  which states that "MM. Hachette & Co. will maintain the current scientific character of the book, but for each edition they will bring about the progress of science by a person they appoint.... “ Ganot’s will to update his text following the developments of both theoretical and technical science, leads to an increase in the number of pages, which will go from 660 to 1100, and the number of printed copies which will go from 360 to a thousand. Drion and Fernet’s book increases by ten pages only between 1861 and 1886. Innovations are added as and when they arise, described in detail and announced on the title page. Thus the 9th edition (1860) is enlarged with "the latest works on acoustics, light and electricity", the 12th (1866) with "30 new engravings including several new technical drawings to be used by students, M. Carré’s freezer, various new devices by M. Tyndall, MM. Fabre and Silbermann’s mercury calorimeter, Dr. Helmholtz’s ophthalmoscope, M. Foucault’s new regulator of electric light, batteries by Callaud and Minotto, M. l’Abbé Caselle’s pantelegraph" It takes little time for these original publications to be introduced in the Treatise: for example, Helmholtz described his ophthalmoscope in the 'Treatise of Physiological Optics', published in 1856. In the 15th edition (1872), the electric machine invented by Gramme in 1869 appears. This constant updating is also reflected in the removal of obsolete equipment: such is the case of the gas microscope - lit by "quicklime kept incandescent by a jet of hydrogen gas that burns with a stream of oxygen gas" - shown and described in the 2nd edition and which disappears in the 3rd edition. Taking into account the theoretical debates In contrast with today’s textbooks, Ganot’s reflects the debate that exists within the scientific world and, at the moment when we are trying to introduce an historical perspective in the teaching of physics, we can see that this dimension is evident throughout Ganot’s work. As the author never explains his positions in a preface, only the comparison of successive editions and comments within the text allow us to have an indication as to his ideas: he is aware of the continuing evolution of knowledge, but also concerned by the constraints in education and the risks linked to the dissemination of concepts which could be too recent to be admitted definitively. For example, the birth of spectroscopy results in a change in the chemical analysis section: the paragraph in the 4th edition (1856) "We now know sixty-two elementary or simple substances, that is to say from which chemical analysis can only extract a single species, but it is possible that later on the number of these substances will increase or decrease, because new ones can be discovered or others may be decomposed into several ones " becomes, in the 14th edition (1870)," Sixty-two elementary or simple substances were known for a long time, that means the chemical analysis of which extracts only one kind of matter. In 1859, this number was increased by three new metals , discovered by using an analytical method due to MM. Bunsen and Kirchhoff (..) In 1863, the same method allowed to find a fourth metal, indium, increasing to sixty-six the number of known simple substances, but it is likely that many of them are combinations". During the second half of the nineteenth century, the evolution of the theoretical interpretation of heat can be followed in the successive editions of the Treatise. The section entitled "Caloric" in the 1866 edition became "Heat" in the 1872 edition and was completed by a section entitled "History of the dynamic theory of heat." In between, the foreword of the 14th edition (1870) states ".... Several new theories have been introduced. The dynamic theory of heat has been exposed in as short and elementary a manner as possible. A single fluid has replaced the assumption of imponderable fluids, abandoned by all sides. This is a hypothesis substituted by another one, that is true, but the new hypothesis is simpler and represents the ideas dominating today. Moreover, these changes have been made with the greatest reserve, and so as not to disturb the habits of education". This concern not to disturb teaching appears in another rapidly growing field in the nineteenth century, electricity (5th edition, p. 526): "Symner’s theory on the two electric fluids lends itself with great simplicity to the explanation of phenomena: so, it is generally accepted in schools, at least in France. However, it must not be forgotten that this is only a hypothesis. Besides, we must admit how vague this name of fluid is applied to the causes of heat, light, magnetism and electricity. What indeed is a fluid? What is its nature? No physicist has given information on that. Thus, we just have to look at the hypothesis of two electric fluids as expressing two states, where electricity comes in the appearance of two equal and opposite forces that tend to be in equilibrium". This introduction of recent theories in textbooks for secondary education was not usual at that time; for example, while the 1866 edition includes a section called "Ohm's Law," the name of the German physicist does not appear in the contemporary work of inspectors Drion and Fernet. This choice to introduce new concepts is reported again by the same critics in 1904: "In the 22nd edition, just published, a place is given to discoveries that have revolutionized the field of electricity and optics in the recent years, especially those of Roentgen and Becquerel as well as Mr and Mrs Curie". Despite Ganot’s precautions, these constant changes are sometimes problematic, as pointed out by a Brazilian translator faced to rather conservative teachers . The influence of the Treatise is undoubted since, for some historians,  Ganot's works have greatly contributed to spreading the idea of the reality of atoms and molecules. Indeed, the first pages the 2nd edition (1853) of the manual mention: "Every limited amount of material is a body. The properties of bodies indicate that they are not made up of continuous matter, but of virtually infinitely small elements, that cannot be physically divided, and are simply juxtaposed without touching, being kept away by mutual attractions and repulsions known as molecular forces. These elements of bodies are called atoms. A group of atoms forms a molecule. Bodies are only aggregates of molecules. Conclusion The posthumous editions published by Hachette, although declared as "completely revised" will in fact change very gradually only. The general structure of the book will remain, the will to describe many technical devices will also remain and developments of the mathematical formalism will be kept limited, thus respecting Ganot’s spirit. Consequently, the mark of the innovative teacher, the well-informed scientist, but also the shrewd businessman will last for many years through a book that will remain popular until the first quarter of the 20th century and will motivate the vocation of several famous physicists. Acknowledgements: The author is very grateful to M. Aurélien Langlois for his kind help in translation. Références et notes The 13th et 17th editions of the Treatise are available on line on the website http://www.gallica.bnf.fr  Léon Foucault carried out, at the Panthéon two years before, the spectacular pendulum experiment which demonstrated Earth’s rotation.  Segré, E., Les physiciens classiques et leurs découvertes, Fayard, Paris ,1987, préface. Emilio Segré (Tivoli 1905 - Lafayette 1989), Nobel prize winner in physics 1959.  Millikan, R., The Autobiography, Prentice-Hall Inc., USA, 1951, p. 14. Robert Millikan (Illinois 1868 - Californie 1953), Nobel prize winner in physics 1923.  Letter to general de Montluisant in 1924, http://rbmn.waika9.com/Krebs_lettre.html. Arthur Constantin Krebs (1850-1935), the scientist who conceived the engine of the French electric submarine « le gymnote ».  Tourgueniev, I., Père et fils, La Pléiade, Gallimard, 1982, p. 627.  Revue générale des sciences pures et appliquées, tome XV, Armand Colin, Paris, 1904, p. 746.  Takata, S., Ganot's textbooks of physics introduced into Japan, Historia Scientiarum JPN, 1987, N° 33, pp. 25-41.  Mattos,C. ,Gaspar,A. , A origem das "propriedades gerais da materia" e a crença dos professores. www.sbf1.if.usp.br/eventos/epef/viii/PDFs/CO23_2.pdf, consulté le 24 septembre 2002.  Larousse, P., Grand dictionnaire du XIXe siècle, supplément tome 2, réédité par Christian Lacour éditeur, Nîmes, 1992.  AHN-F17-20793  Micé, L., Discours d’ouverture de la séance publique du 19 Mai 1881 cité dans : Actes de l'académie de Bordeaux, 3e sér. (1880) 729. D’après : Bensaude-Vincent, B.; Garcia Belemar, A.; Bertomeu Sanchez J.R., La naissance d’une science des manuels (1789-1852), Editions des Archives Contemporaines, Paris, 2003.  Georges Maneuvrier got a classical cursus, « normalien , agrégé et docteur ». He became the director of the physics laboratory at la Sorbonne. He was assisted in 1908 by Marcel Billard, who got the same cursus and taught at lycée Charlemagne in Paris.  No sentence such as the following one can be quoted: " More recently, MM Loir et Drion also succeded in condensing carbonic acid under atmospheric pressure ". Drion, C., Fernet, E., Traité de physique élémentaire , Masson, Paris, 2° éd. 1861; 9°éd. 1886. Charles Drion, normalien, PhD 1859, teacher at lycée St Louis (Paris) then at the university of Besançon ; Emile Fernet, normalien, teacher at lycée St Louis (Paris) then inspector.  Hulin, N., L'organisation de l’enseignement des sciences : la voie ouverte par le second empire, Paris, Editions du C.T.H.S, 1989.  Belhoste, B., Les sciences dans l'enseignement secondaire français, INRP,1995, edition economica, tome 1, 1789-1914, p. 46.  Depretz, C., Traité de physique, Méquignon-Marvis, Paris ,1836.  Becquerel, Traité de l'électricité et du magnétisme, Firmin Didot, Paris, 1855.  Pouillet, C., Eléments de physique expérimentale et de météorologie, Bechet jeune, Paris, 1844.  Caesium, rubidium and thallium  Vaquero, J.M., Santos, A., Heat and Kinetic Theory in 19th-Century Physics Textbooks : the Case of Spain, arXiv:physics/0002042 v1, 22 Feb 2000, p. 3.  Yoda, J., Ernst Mach's Vienna 1895-1930, J Blackmore et al., Kluwer Academic Publishers, Dordrecht, 2001, p. 18.  Archives de l’IMEC, référence HA C2 S30 B28 D21.