French contribution to the study of lubrication Oiliness, molecular influences Application to watch lubrication

Lubrication at the Frontier / D. Dowson et al. (Editors) © 1999 Elsevier Science B.V. All rights reserved.

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French contribution to the study of lubrication Oiliness, molecular influences Application to watch lubrication J. du Parquet Total - C.E.R.T. BP 27, F76700 Harfleur Little is known about the French contribution to the study of oiliness and adsorbed monomolecule layers. The work of Langmuir, Hardy, Doubleday, Rayleigh and others was known to French scientists. G. Friedel, F. Grandjean, even Jean Perrin and Louis de Broglie studied these layers of fatty acids or soaps. The French "Academie des Sciences" was regularly informed of the new results by Marcel Brillouin. As early as 1925, the X Ray experiments of J.J. Trillat showed that lubricating greases and fatty acids did form stratified layers on surfaces. Since 1926, Paul Woog's theory of "molecule trapping" met with less success than the commercial application of his "surface neutralization" process. Thanks to his cooperation with a well known watchmaker, Paul Ditisheim, and a French oil company his range of products allowed a real technical leap in the lubrication of clocks and watches. The range of temperature operation and the reliability of horological production were considerably increased. The modem tribological concept of barrier films, additive competition and oil formulation were already identified by Paul Woog. They led to further developments when new chemicals like silicones and perfluorinated polymers became available.

1. I N T R O D U C T I O N Tribology is considered to be an interdisciplinary science. This is particularly true where a thin oil film separates surfaces in a rubbing contact. Therefore it is not surprising that the understanding of boundary lubrication eventually emerged from studies related to the physical state and flow behaviour of liquids in the vicinity of solids, to their thermodynamic properties and generally speaking to bulk and surface chemistry. The first purpose of this paper is to identify different French contributions to this scientific puzzle in order to fit them into the general picture of boundary lubrication. The second objective is to show how the perfect understanding of the latest scientific discoveries

enabled Professor Paul Woog to solve the ancient problem of watch lubrication.

2. BASIC RESEARCH 2.1. Early optical studies on molecular orientation As early as 1890 a German specialist in crystals O. Lehmann (1) had noticed the birefringence of certain liquids in contact with solid. He made a distinction between viscous flowing crystals and thin flowing crystals. The physical state of these materials attracted the attention of French physicists. From 1910 to 1922 Georges Friedel and Frangois Grandjean (2), Charles Mauguin (3), and even Jean Perrin (4), studied these materials. A review of the work done during this

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period was published by Georges Friedel in 1922 (5). He rejected the expression "liquid crystal" as being incorrect and misleading. He felt necessary to introduce new expressions such as "mesamorphous materials" which were to be divided in two groups : - the first group, corresponding to the "viscous flowing crystals" of Lehmann was originally called "liquids with conic focal" (from their optical properties). But he subsequently suggested a neologism which has been universally adopted: "smectic liquids" (from the Greek word for soap)". - the second group, corresponding to the thin flowing crystals of Lehmann, was first called "liquids with threads". He then suggested that they should be called "nematic fluids" (from the Greek word for thread). In his review, Georges Friedel mentioned the work of Jean Perrin (4) and Philip Varnum Wells (6) who had studied the stratified structure of thin layers of soap. He was also able to show that the structure with equidistant planes, described by Francois Grandjean (7) for cholesteric fluids, belonged to the nematic structure, with the threads having a high rotational power. 2.2. Application of X-Ray diffraction It seems that the first application of X-Ray techniques to the study of surface films was published in 1923 by A. Maller and C. Shearer in the United States (8), and by S.H. Piper and E.N. Grindley in Great Britain (9). It is less known that during the same year, Maurice de Broglie, associated with Edmond Friedel (10), applied the technique to soap layers. They demonstrated that the layers studied by Jean Perrin were not amorphous but had a smectic structure. The techniques of X-Ray diffraction were further developped by Jean Jacques Trillat (11) who applied them to lubricating greases. He greatly improved the quality of the spectra by first dissolving fatty acids in a solvant and by letting it evaporate. Louis de Broglie himself helped Jean-Jacques Trillat in the interpretation of these spectra (12). Thus they complemented the explanations of W. Bragg and showed that the molecules of fatty acids were bound at their ends by the terminal groups CH3. 2.3. Surface film properties and lubrication The pioneering work of Agnes Pockels and Lord Rayleigh on thin films spread on liquid surfaces,

reported in 1891 (13) and 1899, was well known in France. Just before the first world war, W.B. Hardy (14) mentioned the changes in surface energy introduced by polar molecules. During the 1914-1918 period, it is not surprising that important publications on the subject were to be found only in American Journals. I. Langmuir in 1916 (15) (16) and in 1917 (17). W.D. Harkins et al in 1917 (18) developed Hardy's views. But immediately after the first world war, the increase in related publications was spectacular, especially in Great Britain. Lord Rayleigh described the lubricating properties of thin oily films in 1918 (19). During the same year, A.E. Duston and F.B. Thole on one hand (20) and R.M. Deeley on the other hand (21) emphasized the importance of unsaturated molecules. Then in 1919, W.B. Hardy (22) released his first publication on friction and lubrication and drew attention to the adsorption of colloids on surfaces. In France, Marcel Brillouin tried to provide an explanation of oiliness properties. In 1920 (23) he suggested that lubricants were concentrated solutions of anisotropic crystals in a small quantity of viscous isotropic fluid. This concept was compatible with the anisotropic fluids studied by Lehmann and G. Friedel. It implied a viscous behaviour in the flow direction and an elastic behaviour in the transverse direction. But the theory did not account for the oiliness of "normal" fluids. Consequently, Marcel Brillouin initiated research work on oiliness and entrusted Paul Woog with this subject for his thesis at the University of Paris (figure 1). 2.4. Research work of Paul Woog As early as 1921, Marcel Brillouin presented two communications from Paul Woog to the French Academy of Sciences. The first one was the entitled "On the oiliness of fatty materials" (24) and the second "On the dimensions of the molecules of fatty oils and on some phenomena of molecular dissolution" (25). In 19:22 a new communication was presented on "The spreading speed of thin layers of oils on a water surface" (26). In 1925, it was followed by "The measurement of onctuous friction" (27) and by "On the spreading of lubricants on metallic surfaces" (28). Paul Woog's thesis "Contribution to the study of lubrication - oiliness - molecular influences" was

623

defended in Paris on the 17th of July 1926, with Professor Cotton as President of the jury. It was published the same year by the Librairie Delagrave (29). But it was also the basis for an extensive book which was published under the same title by the same editor (30). The oiliness of oils was explained by the socalled theory of "molecule trapping". The first form of trapping is purely steric and similar to the behaviour of granular materials. The second form of trapping accounts not only for the dimensions of the molecules but also for their shape, orientation, adhesion, elasticity and viscosity. The lateral compressional forces, tangent to the surfaces are responsible for the disturbance of the flow. The molecule trapping is said to divide, to distribute, to reduce the disturbance and hence the friction. In addition, the book includes a last chapter of 41 pages "Conclusions - Applications" (Choosing lubricants - Improving lubricants - Artificial lubricants) with one page devoted to watch lubrication and to the special process of surface neutralization. More research work was carried out by Doctor Paul Woog after he graduated. In 1928, he received the arreas of the Foundation Cldment Felix of the French Academy of Sciences, in order to "carry on his work on oiliness" (31). The members of the Committee who showed their interest in the study of oiliness had names as famous as : Joseph Boussinesq, Emile Picard, Paul Villard, Edouard Branly, Paul Janet, Jean Perrin, Aim6 Cotton, Edouard Fabry and Marcel Brillouin.

3. APPLICATION TO INDUSTRIAL LUBRICATION 3.1. Connection between academical work and petroleum industry In 1920, Professor George Friedel was appointed Director of the newly created Institute of geological sciences at the University of Strasbourg, close to the French oil field of Pechelbronn. When the Institute of Petroleum was created in 1922, Paul Woog was requested to read courses on viscosity and lubrication. He retained the same responsibilities at the Ecole Nationale Sup6rieure du Pdtrole et des Combustibles founded in 1924.

As soon as it was created in 1929, the Compagnie Frangaise de Raffinage decided to have the best possible research laboratory. In 1931, the new buildings of the Laboratoire Central in Paris were inaugurated, with Doctor Paul Woog as Director. His terms of reference were "the study of processes related to petroleum industry and the control of quality products". From the very beginning, the Laboratoire Central included a Department for watch lubrication and this needs some preliminary explanations. 3.2. The watch lubrication problem Since Huygens had invented the first pendulum clock in 1657 and the balance-wheel watch in 1675, the oil problem was considered as a nightmare by all clock makers. Friction and wear problems were described in 1714 by the French clock maker Henry Sully (32) : "Friction is almost the only obstacle to the perfecting of mechanics... Oil is absolutely necessary to prevent wear of constantly rubbing metals, even if the value of friction changes as a consequence of the drying or evaporation of the oil". During the same year 1714, the Longitude Act was passed by the British Parliament with a prize of £20,000 to reward any accurate and practical solution to the determination of longitude at sea. The carpenters' clocks (Harrison 1,2 and 3) were built by John Harrison from Yorkshire with self lubricating tropical hardwood and selected oakwood for the rubbing parts. They almost solved the problem of lubrication, wear and corrosion. But the fourth instrument H4 built by John Harrison in his competition for the Parliament Prize was in fact a watch, not a marine clock. Harrison used diamonds and rubies to reduce friction and wear, but he was unable to miniaturize the anti-friction wheels (and caged ball bearing of H3) so that he had to come back to lubrication. In 1762, H4 successfully passed the trial imposed by the Board of Longitude (five seconds lost after the 81 days voyage from Portsmouth to Jamaica, i.e. one minute and fifteen seconds in longitude against a requirement of 30 minutes). Paradoxically, the marine clocks H1, H2, H3 are still working in the National Maritime Museum in Greenwich, while the lubricated watch H4 would require such repairs that it was preferred to keep intact this historical piece of horology with all its original components. Obviously, lubrication at the time was not a long term solution.

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The fascinating book "Longitude" by Dava Sobel (33) does justice to the contribution of John Harrison to the quest for the Longitude, but the demand for the perfect oil had still to wait an answer for nearly two centuries... According to a tradition reported by Paul Chamberlain (34), the following dialogue took place between Napoleon and Abraham Louis Breguet, a French watchmaker, a native of Neuchatel : "Give me a perfect oil and I will give you a perfect watch" said Breguet to Napoleon. Napoleon had in a manner dared Breguet to make a clock for him which would wind the watch at midnight, set it to the exact time and move the regulator if necessary". In 1869, Henry Robert, a famous watchmaker appointed by the French State Navy found it necessary to publish again his "Summary on practical considerations on oils used in watch making" (35). The first paragraph reads as follows: "There is no perfect oil. Nothing is more frequent than hearing watch makers complain about the bad quality of the oil used to ease the friction between clock parts. Several of them have made great efforts to find methods which would give a constantly good oil. Celebrated chemists tackled the problem and nevertheless, all the work done up to now has produced nothing which could be considered as perfect, in all the force of that word".

3.3. Cooperation between watch makers and Paul Woog Charles Edouard Guillaume, Director of the Bureau Intemational des Poids et Mesures was very much involved in time control. He received the Nobel prize in 1920. He was the inventor of the alloys Invar and Elinvar. His spiral spring made of Elinvar which had an elasticity independent of temperature was further improved in 1922 by a famous watch maker of Neuchfitel, living in Paris, Paul Ditisheim. About 1925, at the request of the British Aviation Ministry, the British Engineering Standard Association established a test programme for watches and chronometers designed for aviation purpose between-60 and +60°C (an interval later moved to -20 to +100°C) instead of the usual interval +4 to +32°C. It was Doctor Guillaume who introduced Paul Ditisheim to Doctor Paul Woog whose patented process of neutralizing surface force fields

prevented the mineral oils from spreading out over metallic surfaces (36). The technical success of their cooperation was immediate. The watches lubricated with mineral oils passed the most severe tests of the National Physical Laboratory at Teddington in the best possible conditions. The results were similar in Neuchfitel and Besam;on (37) (38). An official presentation was made in London at the Exhibition of chronometers and watches organized by the Physical Society in 1926. As can be seen in figures (2) and (3) the technical press was as enthousiastic as the newpapers : "remarkable achievement", "genius of Mr Woog from Paris". The first version of the neutralization process, called Sigma and the first oils of Paul Ditisheim were further improved by the Laboratoire Central of the Compagnie Fram;aise de Raffinage.

4. THE EPILAME PROCESS

4.1. Original presentation of the Epilame process (figure 4a) The first patent on the method of "neutralizing metallic surfaces" was granted to Paul Woog's first employer George Wisner in Paris on the 1 l th of June 1925 under the title : "Improvement of the lubrication of mechanical components" (39). It refers especially to small mechanisms such as clock mechanisms. The patent starts from the fact that fatty oils currently used resist the attraction field of the metal but are too viscous at low temperature and unstable at high temperature. On the contrary, mineral oils may be both fluid at low temperature and stable at high temperature, but they spread out on metallic surfaces because of the attraction of the metal. The patent claims an improvement "consisting in the preliminary neutralization of the attraction field of the surfaces by depositing a layer of neutralizing substances, fatty acid or similar, in order to subsequently allow the lubrication of these components with liquids having liquid cohesion such as mineral oil, without any risk of spreading of the said liquids onto surrounding surfaces. In the communication to the French Academy of Sciences which followed on the 23rd of November 1925 (28), Paul Woog explains that "on the surface of a solid.., when a ring of oriented molecules is formed on the edges of the drop, this kind of barrier

625

anchored on the solid modifies completely the appearance of the phenomenon. The active centers here mainly act by mutual attraction which is no longer counterbalanced by the attraction of the surface, the latter being neutralized by the fringe of oriented molecules. Thus a better apparent cohesion of the active molecules is to be found". Fifty two years before the concept of barrier films was described in the standard MIL-STD-1334 in 1977, Paul Woog described the barrier effect of the oriented molecules. He named the neutralizing layer Epilamen. The original process Sigma was later improved and renamed Epilame. The original patent received two additions. The first one in 1929 (40) claims that the invention is also valid for blends of mineral oils with fatty oils. The second addition in 1931 (41) combines the neutralizing effect with the anticorrosion properties of a varnish (figure 4b). In 1951, a US patent (42) was granted to a further improvement of the Epilame. The stearic acid was replaced by a baryum stearate which resisted abrasion better and remained effective from -60 to +IO0°C. Several processes called "epilamages" using silicones and derivatives as well as perfluorated polymers have been developed following the success of the Epilame (43) (44) (45) (46) (47). 4.2. The theories

Epilame process

in the light of modern

The work of Marcel Brillouin and Paul Woog is well known from Russian scientists and often quoted by A.S. Akhmatov (48). In 1964, M. K. Bernett and W.A. Zisman (49) provided the fundamental explanation of the Epilame process : "Essentially, the Epilame is a modification of surface substrate. A close-packed adsorbed monolayer of higher fatty acid, such as stearic acid, has a 7c value of 24 dynes par cm. Any oil and other liquid having a surface tension 7Lvo, at 20°C, greater than 24 dynes per cm would therefore be nonspreading on such a monolayer, and the equilibrium contact angle would be greater the larger the difference from liquid surface tension to critical surface tension". In the literature review presented at the same Symposium (50), Zisman provides a possible explanation for the fact that Paul Woog systematically avoid any reference to the contact angles which had been defined by Thomas Young as early as 1805. Until 1936, when R. Wenzel

developed a relation between macroscopic roughness of a solid surface and the contact angle, the measurements of contact angles were not considered as reliable by scientific authorities because they were not reproducible. The main criticism formulated by Zisman about the Epilame process were : a / a new treatment was necessary after solvent cleaning (is it a handicap in the case of watches ?) and b/the process itself would promote oxidation (or corrosion ? the varnish Epilame was designed to overcome this problem).

5. F O R M U L A T I O N OF LUBRICATING OILS FOR W A T C H M A K I N G Whereas Europe still used neat's foot oil or sheep's foot oil and the United States prefered oil from the head of the porpoise, Paul Woog developed pure mineral oils sometimes blended with animal oils. These oils were specially treated to improve their purity and low temperature behaviour. They were also treated with anti oxidant additives. 5.1. Stabilization against oxidation - Compatibility of additives

Paul Woog (51) knew very well the work done by the French chemists Charles Mouren and Charles Dufraine on the inhibition of acrolein by the socalled "antioxygene agents" such as phenols, diphenylamins naphtylamins... He used them in order to stabilize the commercial oil Chronax (figures 4c and d). But he also observed that some of these chemicals formed a surface layer of their own which reduced the lubricating efficiency. Hence Paul Woog's idea to add to these antioxygene agents, introduced to protect the bulk oil, some molecules of a chemical product which could show "a greater affinity for the solid surfaces" and would deplace the antioxygene molecules already adsorbed". This mechanism of additive competitivity was fully described in the French patent "Improvement in lubricants" granted in Paris on the 13th of March 1926 (52) and its addition of 1927 (53). The phenomena became even more important with the introduction of new additives in oil formulation (54) (55) (56) (57) (58).

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5.2. Stabilization against light The French patent "Means of protection of lubricants against the action of light" was granted in Paris on the 2nd of December 1929 (59). It describes the use of yellow or red opaque dyes as built-in filters of UV Rays. For the stabilized oil Chronax red dye was preferred as it recalled the colour of the ruby stones used in clocks and watches.

6. CONCLUSION There is not enough room here to describe all the innovations introduced by Professor Paul Woog in the field of watch lubrication and industrial lubrication. Some of them are to be found in reference (60). It is hoped that the examples given in this paper will increase the international recognition of the French contribution to lubrication problems in the twenties. It might be adequate to quote the last words of Paul Woog's book published in 1926 (30) : "ART OF OILING, SCIENCE OF LUBRICATION Now that we have reached the end of the programme we set ourselves, we feel better than ever how justified is the title of our work : Contribution to the study of lubrication. As has been seen, the question of oiling is most complex, and only a deep scientific study will allow it to be mastered : but on the basis of such a study, whose mathematical analysis has already enlightened some fields, we are convinced that the Art of Oiling, based on passed experience, will evolve to a Science of Lubrication, henceforth permitting a better efficiency of the forces used by human beings". If the concept of Tribology emerged only forty years later, it is certain that it was already conceived and evoked by Paul Woog in 1926.

REFERENCES 1. 2. 3. 4. 5.

Lehmann O., Ann. der Phys., t.XL, 1890, p.401 ; t.41, 1890, p.525 Friedel G. and Grandjean F., Bull. Soc. Min., t.33, 1910, p.192 Mauguin h., Bull. Soc. Min., t.34, 1911, p.71 Perrin J., Ann. Phys., i-9, t. 10, 1918, p. 160 Friedel G., Ann. Phys. s-9, t. 18, 1922, p.273

6. 7.

Wells Ph-V, Ann. Phys. s.9, t. 10, 1918, p. 160 Grandjean F., Bull. Soc. Min., t.xxxiv, 1916, p.164 8. Mt~ller A., and Shearer, G., J. Chem. Soc., vol. 123, 1923, p.2083, 3152 9. Piper S.H. and Grindley, E.N., Proc. Phys. Soc., t.35, 1923, p.269 10. de Broglie M. and Friedel, E., C.R. Ac. Sc., t.176, 1923, p.738 11. Trillat J.J., C.R. Ac. Sc., t.180, 1925, p.280, 1838 12. de Broglie L. and Trillat, J.J., C.R. Ac. Sc., t.180, 1925, p.1485 13 Rayleigh J.W.S., Nature, 02.03.1891 and 12.03.1891 14. Hardy W.B., Proc. Roy. Soc., s.A., t.88, 1913, p.303 15. Langmuir I., Chem. Mct. Eng., t. 15, 1916, p.468 16. Langmuir I., J. Am. Chem. Soc., t.38, 1916, p.2221 17 Langmuir I., J. Am. Chem. Soc., t.39, 1917, p.1848 18. Harkins W.D., Davies and Clark, J. Am. Chem. Soc., t.39, 1917, p.1848 19. Rayleigh J.W.S., Phil. Mag. t.35, 1918, p.157 20. Dunstan A.E. and Thole, F.B., J. Petr. Tech., t.4, June 1918, p. 191,205,206 21. Deeley R.M., Proc. Phys. Soc., t.32, part II, 1920, p.15 22. Hardy W.B. and Hardy J.K. Phil. Mag., $6, 38, 1919, p.32 23. Brillouin M., J. Phys. et Rad., t. 1, 1920, p.33 24. Woog P., C.R. Ac. Sc., t.173, 1921, p.303 25. Woog P., C.R. Ac. Sc., t.173, 1921, p.387 26. Woog P., C.R. Ac. Sc, t. 174, 1922, p. 162 27. Woog P., C.R. Ac. Sc., t.180, 1925, p.1284 28. Woog P., C.R. Ac. Sc., t. 181, 1925, p.772 29. Woog P., "Contribution ~ l'6tude du graissage, oncuosit6, influences mol6culaires"- th6ses pr6sent6es h l'Acad6mie des Sciences, Paris, Delagrave, 1926 30. Woog P., "Contribution h l'6tude du graissage, onctuosit6, influences mol6culaires" Paris, Delagrave, 1926 31. C.R. Ac. Sc., t.187, 1928, p.1208 32. Sully H., "R6gle artificielle du temps, trait6 de la division naturelle et artificielle du temps, des horloges et des montres de diff6rentes constructions,...", Paris, G. Dupuis, 1737, p.206

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33. Sobel, D. "Longitude", Fourth Estate Ltd., London 1996, ISBN 1-85702-571-7. 34. Chamberlain P.M., "Laboratory Research and the Solution of the Watch lubrication problem", The Horological Journal, March 1936 35. Robert H., "Abr6g6 de consid6rations pratiques sur l'huile employ6e en horlogerie", Paris, 1869 36. Ditisheim P., "Sur l'emploi des huiles d'horlogerie naturelles et artificielles", Revue Opt. Theor. Instrum, 1939 37. Ditisheim P., "Etat actuel de la question du graissage en horlogerie" Ann Franc. Chronometrie, N°2, 1931 38 Ditisheim P. "Bull. Ann. Sce et LSRH, Berne, 1932, p.27-29 39. Wisner G. Brevet Fr., Gr., C1.3, N ° 612.077, 11.06.1925 40. Idem, Add. 1, N ° 37667, 1929 41. Idem, Add. 2, N ° 40504, 1931 42. Woog P. and CFR, US Pat. N°2, 673, 818, 1951 43. Brilli6 H., "Influence de l'6tat de Surface sur les Ph6nom6nes de Lubrification", Compagnie G6n6rale Transatlantique, 3 Journ6es Int. Chrono. & M6trologie, 1937, Paris, p.590-618 44. Dinichert P., Renauld J., "Etats de Surface et Etalement des Huiles d'horlogerie", Laboratoire Suisse de Recherche Horlog6re, 31 Bulletin Annuel de la SSC & LSRH, 1956, Neuchfitel, p.681-696 45. Massin M., "Epilames et Lubrifiants Associds /~ Haute Stabilit6 - Rdsultats en Horlogerie", CETEHOR- Centre Technique de l'Industrie Horlog6re, Bulletin Annuel de la SSC & LSRH, 1970, Lucerne, p.93-98 46. Renaud J.P., Renfer A., "M6thodes de Nettoyage et Comportement des Huiles d'horlogerie sur les Rubis, LSRH Laboratoire Suisse de Recherche Horlog6re, 06 Congr6s Int. de Chrono., 1959, Munich, p.779-788 47. Renaud J.P., Renfer A., "Contr61e de l'6tat de Propret6 des Surfaces par des Mesures d'6talement d'huile", LSRH - Laboratoire Suisse de Recherche Horlog6re, 48 Bulletin Annuel de la SSC & LSRH, 1973, Lausanne, p.447-453

48. Akhmatov A.S., "Molecular Physics of Boundary Friction", Israel Program for Scientific Translations, Jerusalem, 1966, p.217-218, 308-309, 317, 322-323,328 49. Bemett M.K., and Zisman W.A., "Prevention of Liquid Spreading or creeping", in Contact Angle, wettability and adhesion, Advances in Chemistry series 43, ACS, 1964, p.232-340 50. Zisman W.A., "Relation of the Equilibrium Contact Angle to Liquid and Solid Constitution", Advances in Chemistry Series, ACS, 1964, p. 1-51 51. Woog P., "Etude sur la Stabilisation des Huiles pour l'horlogerie", Annales Fran~:aises de Chronom6trie, N°2, 1931 52. Wisner G., Brevet Fr., Gr. 14 - C1.4, N ° 646.756, 1926 53. Idem, Add. 1, N ° 36.428, 1927 54. Dtirr F., "Une contribution au sujet des Tests M6caniques Dynamiques des Lubrifiants", Universitt Stuttgart, 08 Congr6s Int. de Chrono., (C) 1969, Paris, p.C32001/1-23, Allemand 55. Renaud J.P., Renfer A., "Essais d'usure sur la Machine /l Quatre Billes, Applications aux Lubrifiants utilis6s en Horlogerie et en Microm6canique", LSRH - Laboratoire Suisse de Recherche Horlog6re, 09 Congr6s Int. de Chrono., (D), 1974, Stuttgart, p.D3.10 56. Renaud J.P., "Expos6 de Synth6se ; Frottement, Usure, Lubrification", LSRH Laboratoire Suisse de Recherche Horlog6re, 49 Bulletin Annuel de la SSC & LSRH, 1974, Gen6ve, p. 715-720 57. Renaud J.P., Renfer A., "Essais d'usure sur la Machine /t Quatre Billes. Applications aux Lubrifiants utilis6s en Horlogerie et en Micromdcanique", LSRH 6 Laboratoire Suisse de Recherche Horlog~re, 49 Bulletin Annuel de la SSC & LSRH, 1974, Gen6ve, p.741-748 58. Maillat M., "Am61iorations apport6es aux huiles d'horlogerie en relation avec des mesures de frottement et d'amplitude - Lien entre le frottement et l'amplitude" - LSRH Laboratoire Suisse de Recherche Horlog6re, 10 Congr6s Int. de Chrono (3), 1979, (54 CSC), Gen6ve, p.401-412 59. C.F.R., Brevet, Fr., Gr. 14 - C1. 4, N°701.522, 1929

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60. du Parquet J., "Horlogerie m6canique et tribologie" - Actes des Joum6es Intemationales Francophones de Tribologie 1997, SIRPE, Paris, 1998.

M. W ~ Directeur des Laboratoires de la Compagnie Francaise de Ra~inage.

Figure 1

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TIlE WATCHblAI(ER, JEWELER

SII.VERSblITII AND OPTICIAN NEW

WATCH

for E X T R E M E

TEMPERATURES',

Amollg t lie exhibits at. tim Pilysica.l Society's Exhibition were a number of cllronomelers and watches by Paul Ditisheim, of Ln Chaux-de-Fonds, Switzerland. This manufaclurer llol(Is tile best reconls sil~ce 1905 ill t.lm Kew Trials. One o[ the watches shown havillg obtained 97 marks in the 1924 tests attracted considerable attention whilsg another piece was exl~ibited witl~ its curl'iculum vit,-e in the shape of five different certificates: Record at Geneva Observatory, NeuchMel Observatory, Besan~;on Observatory, besides having reached 96.5 marks at Kew. This timekeeper obtained 892 marks at Geneva Observatory, the previous best. result being 879 only. Tl~e high degree o[ accuracy reached is due partly to simplicity and robustness of design, but, largely to the scientific t r e a t m e n t of the compensation problem. Paul Ditisheim uses balance springs made o[ Guillaume's Elinvar alloy, which does not vary in elasticity v,"~ temperature and is, in addition, non-magnetic an(i inoxydizable. The balance is a simple, solid wheel, rendered adjustable by two bimetallic " affixes." This combination gives the most accurate compensation at all temperatures, and is being used in a new, machine-made pocket watch wl~iel~ has recently been tested at NeuchStel Observatory between - 6 ° Fahr. and + 119 ° Fahr. ('that~ is to say, beLween arctic and tropical extremes). Over that~ unprecedently wide ravage it shows only m i n u t e cl~anges ill rate; a remarkable achievement, duo to the use o[ a special lubricat, ing oil developed by M. P a u l Ditisheim in conjunction with M. Paul Wo££ga o[ Paris. Tile lubricanL r e m a i n s fluid within the temperature range indicated, and in order that~ it; shall be retained in the bearings to wl~ich it is applied, the metal is " neutralized " b y dipping in a preparation which prevents the oil spreading. In exploration work and on aeroplanes this invention should prove invaluable.

THE

CLOCKMAKERS'

COMPANY.

At the Christmas Quarter Court,. held on J a n u a r y l l t h , Ernest Edward Finch, Esquire, Chie[ Engineer to the Corporation o[ the City o[ London, was admitted to the Freedom and elected to the Livery. In addition to t,ho usual subscriptions to cra.[[ charities, the Company made tile undermenlioned donations : - Clerkenwell Maternity I n s t i t u t i o n , £5 5s. Clel'kellwell Police Court., £5 5s. City of London Pension Society, £5 5s. Police Courl~ Mission, £5 5s. Hoxton Market Mission, £5 5s. The Court decided to accept, an invitation, received from the President of t h e Board o[ Education through the Victoria and hlbert~ Museum, to loan their Collection o[ Clocks to the Exhibition to be held at South Kensington next Summer.

Figure 2

tfie~:hd0pt'roli of a slyle-:--a l:ath.ol.ic style, I ..... if you'iwill--wli.i'cll Ihe oouturicrs v,ould I'P.res IJe.,'-~l)l'[ged to f o l l o w . ~ e can never l °lsn -l"AVh'eri .,Cat,ho~i(~ ,France ~nows l.ne-r~ .~. wa.~. in/~al:s.'fl/Cld~for modest.y, Catholic , " •

do

WATCH AND THE CHRONOMETER. .

/t/

STUDY ....

•

IN

MECHANICAL

INTELLIGENCE.

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"Dally Express" Speolai ..Representative. I went to see an exhibition of chronometers and WatChes at the llbyal Instil u t i 0 n in Albenmrle.street and came away chastened. These instruments are not watches in tl~e p o p u l a r sense ot t h e w o r d . "131iey are i n h u m a n l y accurale. Ti~ey gain or lose a second or two a day--the best watch does this; but you c a n .rely on them to gain or lose constantly. They never vary. " T h e i r virtue lies in thetr balance springs, made of an alloy--Elinvar-I h a t never varies in elasticity, despite '~changing t e ~ p e r a l u r e s . Chronometers have, too, a superior system of lubrication'. They enjoy the benefit of t h e . g e n i u s of Mr .Woog, of Paris, who discovered d~ow to prevent mineral, oils spreading by coatlng, the mechanism witl~ an acid .preparation. Mineral oils are really better than the less spreading sheep's foot and fishoils used i n ordinary xVatches: I took o u t . m y watch in the presence of the demonstrator to compare It with the c h r o n o m e t e r s : it had stopped. As an example of supreme tact I think this would be l~ard to beat. .

Figure 3

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DI~PA, R T E M E : N T HUIL:ES D'HORLOGERIE Dt~LI~:GATION G~_N~RALE • P A U L D I T I S H E I M •

E P 1L A M E PROCESS THE EPILAME BATH EFFECTIVELY PREVENTS M I N E R A L A N D O T H E R OILS F R O M S P R E A D I N G A N D = IS S P E C I A L L Y S U I T A B L E F O R W A T C H E S , CLOCKS AND SM:ALL MECHANISMS.

A.

S P R E A D S S 'U R F A C E ~1S U S E D

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$ H O W ' I N G E F F E C T OF' T R E A T I N G S U R F A C E 'WI;TPI EPIL, AME SOLUTION, THE OIL FORMS A GLOBULE ~D DOES N O T S P R E A D

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VERNIS Ilrc~~.l("

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Les vernis habituels employ6s dans les fabriques de r6veils, eompteurs, etc., sont efficaces pour prot~ger la surface des platines de laiton eontre l'oxTdation, mais ces v e m i s p r o v o q u e n t la disparition p r e s q u e i m m e d i a t e des huiles. Le ~t:,t~ \ I~ E P I L A M E assure, au contraire, le m a i n t i e n du graissage. II p r u r i e n t l ' d t a l e m e n t des huiles et joint a u x qualit~s de I ' E P I L A M E ses propri~t~s de V E R N I S p r o t e c t e u r des surfaces (consul-

ter le Mode d' Emploi). Le t t!III~N I~ E P I L A M E s'obtient sous la forme repr~sent~e page 4, en bidons de 1 litre et en bidons de 5 litres.

Figure 4 b

H UILES

CHRONAX

STABILISEES

Ces huiles de colrleur rouge-rubis, poss~dent une stabilit6 remarquable et assurent un graissage de choix p e n d a n t une dur6e considdrable. Les qualit6s sp6ciales des H U I L E S CHRf~X=~X ST ABIIII~ISEES rdsultent d ' u n t r a i t e m e n t fait au m o y e n de certaines substances Antioxygbnes qui prdvient leur ddcomposition : s i m u l t a n ~ m e n t , des corps a b s o r b a n t les rayons, actiniques e m p ~ c h e n t les alterations ddtermindes par l'action de la lumibre. Les Huiles C H R O N A X ~.T ~ B ILI S t!!~E ~ sont livrdes c o m m e suit au m~me t a r i f que les Huiles C H R O N A X normales, qu'elles sont appeldes h remplacer : Flacons 5 gr. Flacons 15 gr. Type ES en ~tui Flacons 30 gr. Type FS aluminium Type industriel Types AS .... Flacons 125 gr. BS ....CS .....DS Types A I S - BIS ..... CIS - FIS

Figure 4 c

632

TABLEAU DES VISCOSITES Waleur~ des, ,eoelli(.',ients

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Huiles CHRONAX Type A 26,7 eentipoises Type B 33,7 ci:n6mat:iques Type C 40,6 ou Type D. E. 49,5 eentistokes Type F 54,7

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MIN E R A

26,9 cent:ipoises 34,2 ein6matiques 41,3 ou 49,7 centistokes 67,4 .............

La valeur de la viscosit6 de chaque type d'huile est indiqu6e avec pr6cision pour tous les lubrifiants sortant ratoires.

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Barillet Moteur I tour en 8 heures ( fortes pie.ions )

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18.000 oscillations I.............._ ~_ I'heute