Revista CENIC. Ciencias Químicas ISSN: 1015-8553 [email protected] Centro Nacional de Investigaciones Científicas Cuba

Wisniak, Jaime Guillaume Amontons Revista CENIC. Ciencias Químicas, vol. 36, núm. 3, 2005, pp. 187-195 Centro Nacional de Investigaciones Científicas La Habana, Cuba

Disponible en: http://www.redalyc.org/articulo.oa?id=181620584008

Cómo citar el artículo Número completo Sistema de Información Científica Más información del artículo Red de Revistas Científicas de América Latina, el Caribe, España y Portugal Página de la revista en redalyc.org Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto Revista CENIC Ciencias Químicas, Vol. 36, No. 3, 2005.

Guillaume Amontons

Jaime Wisniak.

Department of Chemical Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel 84105. [email protected]

Recibido: 24 de agosto de 2004. Aceptado: 28 de octubre de 2004.

Palabras clave: barómetro, termometría, cero absoluto, higrómetro, telégrafo, máquina de combustión externa, fricción en las máquinas. Key words: barometer, thermometry, absolute zero, hygrometer, telegraph, external-combustion machine, friction in machines.

RESUMEN. Guillaume Amontons (1663-1705) fue un experimentador que se de- Many instruments had been de- dicó a la mejora de instrumentos usados en física, en particular, el barómetro y el veloped to measure in a gross man- termómetro. Dentro de ellos se destacan, en particular, un barómetro plegable, ner the humidity of air. Almost all un barómetro sin cisterna para usos marítimos, y un higrómetro. Experimentó systems made use of the hygro- con el termómetro de aire e hizo notar que con dicho aparato el máximo frío sería scopic properties of vegetable or aquel que reduciría el resorte (presión) del aire a cero, siendo así, el primero que animal fibers such as hemp, oats, dedujo la presencia de un cero absoluto de temperatura. Durante sus estudios leather, or strips of wood. These sobre el comportamiento del aire estableció que a volumen constante la presión materials were held by a weight or varía en forma inversa a la temperatura. Desarrolló una máquina de combustión spring in such a way to displace an externa y fue uno de los primeros en estudiar el roce en las máquinas (leyes de index in front of an arbitrary scale Amontons-Coulomb). as they expanded or contracted [The ABSTRACT. Guillaume Amontons (1663-1705) was an experimentalist who de- modern hair hygrometer was in- voted himself to the improvement of instruments employed in physical experi- vented by Horace Bénédict de .3 ments, particularly the barometer, and the thermometer. Of special note are a Saussure (1740-1799) in 1783] In folded barometer, a cisternless barometer to be used at sea, and a hygrometer of the year 1687, when he was only his invention. He experimented with an air-thermometer and pointed out that twenty-four years old, Amontons the extreme cold of such a thermometer would be that which reduced the spring presented a new hygroscope of his of the air (pressure) to nothing, thus being the first to recognize that the use of air design to the Académie des Sci- as a thermometric substance led to the inference of the existence of a zero of ences, which met with general ap- temperature. During his studies on the behavior of air he established that at probation His apparatus, based on constant volume the pressure varied inversely to the temperature. He devised an the expansion and contraction of a external-combustion machine and was among the first to study problems due to substance as it absorbs and loses friction in machines (Amontons-Coulomb laws). atmospheric moisture, consisted of a ball of beech wood, horn, or leather filled with mercury; it varied in size according to the humidity of the at- SOME DETAILS ABOUT LIFE this as a handicap, he considered it a mosphere. AND CAREER blessing, because it allowed him to Between 1688 and 1695 he devel- There are very few details about concentrate on his scientific work oped one of the first optical tele- the life and career of Guillaume without interruption. After unsuc- graph, which he thought would be Amontons; most of them appear in cessful labor to build up a perpetual of help to deaf people. In his scheme the obituary published by Bernard motion machine, he decided, de- messages were transmitted by le Bouvier de Fontenelle (1657-1757) spite his family disagreement, to means of a bright light that was vis- shortly after Amontons’s death.1 study physical sciences, celestial ible to a person with a telescope at Guillaume Amontons was born mechanics, and mathematics, as the next station. Although he dem- in Paris on August 31, 1663, the son well as drawing, surveying, and ar- onstrated it to the King some time of an advocate who had left his na- chitecture. So far as is known he did between 1688 and 1695, it was never tive province of Normandy and es- not attend a university. Afterwards, adopted. As early as 1699 he pro- tablished himself at Paris. When after being employed on various posed a thermal motor, a machine Amontons was in the third form public works projects that gave him using hot air and external combus- (Troisiéme) of the Latin school at a practical knowledge of applied tion with direct rotation. In this Paris he became very sick and con- mechanics, he devoted himself to work he made his first observations tracted such a deafness that obliged the development, improvement, regarding the phenomenon of fric- him to renounce all communications and design of physical instru- tion. The experiments carried on in with mankind. Far from regarding ments.2 connection with this machine led 187 Revista CENIC Ciencias Químicas, Vol. 36, No. 3, 2005.

him also to note that ordinary air pressure of 30 inches of mercury is ent coefficients of expansion, he going from the temperature of ice heated to the boiling temperature was able to establish that the theory to that of boiling water increases its of water the pressure increases by that “liquids condense and cool volume by about one third. In the about one third, to 40 inches, while first, before expanding with ap- same year Amontons published one air at 60 inches increases to 80 inches, proaching heat” was incorrect be- of the first known experimental and so forth. He observed that for cause the observed results were studies on the question of losses an equal elevation of temperature actually due to the expansion of the caused by friction in machines. The the increase of pressure of a gas was containers. Also, using a barometer well-known Amonton’s laws were in always in the same proportion, no as an altimeter, he tried to verify the reality a rediscovery of similar facts matter what the initial pressure. On exactitude of Mariotte’s law at low described by Leonardo da Vinci the basis of the latter finding he pressures. (1452-1519) years before. Amontons’s proposed an explanation for certain In 1695 he published his only book, work included a clear statement of catastrophes, such as earthquakes: Remarques et experiences physiques the laws of proportionality between If there is air deep within the earth, sur la construction d’une nouvette the friction and the mutual pressure it is extremely compressed and clepsydre, sur les barometres, les of the bodies in contact, as well as could reach an irresistible pressure thermometres et les hygrometers14 in an explanation of the causes of fric- as a result of a relatively small in- which he summarized all his work tion. crease in temperature. on the development of instruments. In 1695 Amontons sought to re- Amontons developed the air The book was dedicated to the new the use of the clepsydra (Note 1), thermometer, which relied on the Académie des Sciences. operated by the flow of water as a increase in volume of a gas with Amontons was appointed membre timing apparatus on ships in order temperature rather than the in- premier titulaire of the reformed to solve the problem of determining crease in volume of a liquid. With Académie in 1690, after being rec- longitude at sea. He proposed that its aid he found that Newton’s law ommended by the astronomer Jean his clepsydra could be used at sea, of cooling was seriously inaccurate. Le Févre (1652-1706). although it would not have been ac- Using the air thermometer he de- According to Fontanelle1 Amontons curate enough to measure longi- vised a method to measure the lived a very healthy life until the tude. change in temperature in terms of beginning of October 1705 when he Between 1702 and 1703 Amontons a proportional change in pressure. had a sudden acute attack of peri- published some important papers He experimented with an air-ther- tonitis; the following infection led on thermometry, thermometers, mometer, in which the temperature to his death on October 11, 1705, at and on practical ways of graduating was defined by measuring the the age of forty-two. His wife and a ordinary alcohol thermometers. Af- length of a column of mercury, and two-month old daughter survived ter observing that the temperature pointed out that the extreme cold him. of water remained constant once it of such a thermometer would be A two-kilometer diameter moon achieved its boiling point, he pro- that which reduced the “spring” crater located at the coordinates 5° posed that the latter be used as the (pressure) of the air to nothing, thus 18' S/46° 48' O is named after Amon- fixed thermometric point. He was being the first to recognize that the tons. one of the first to realize the impor- use of air as a thermometric sub- tance of measuring the thermal ex- stance led to the inference of the SCIENTIFIC CONTRIBUTIONS pansion of elastic fluids. In the ab- existence of a zero of temperature.8 In the course of his compara- sence of an established thermometric Amonton’s dedicated much of tively brief career Amontons made scale, and without an accurate ther- his last years to the study of the a number of important discoveries mometer, he could do little more barometer and built some im- and put forward some very valuable than estimate that air expands, or proved models of the same.9-13 In ideas. His activities as an expert in- that its pressure increases by about 1688 he developed his shortened strument maker led to several fun- one-third between the temperatures barometer, composed of several damental contributions in several of cold and of boiling water. He dis- parallel tubes connected alterna- areas of physics, which will now be covered that unequal amounts of air tively at the top and bottom, with described in detail. equally heated increased equally in only alternated tubes containing pressure and went on to show that mercury. Another instrument was Gases the relative increase in pressure was a barometer with a U-tube, without Bernoulli, in his book Hydro- independent of the initial pressure an open surface of mercury, to be dyanmica,15 refers to Amontons and dependent only on the rise in used on shipboard. Using the same work as follows: “The theorem set temperature, so that if cold air at a receptacle and liquids with differ- out in the preceding paragraph,

Note 1. The clepsydra was a horological instrument of great antiquity, used by the Egyptians and other eastern nations. It is based on the constant dropping, or running of water through a small aperture, out of one vessel into another. In its simplest form it was a short-necked earthenware globe of known capacity, pierced at the bottom with several small holes, through which the water escaped or stole away. At first the indication of time was effected by marks corresponding to either the diminution of the fluid in the containing vessel, during the time of emptying, or to the increase of the fluid in the receiving vessel during its time of filling; but it was soon found, that the escape of the water was much more rapid out of the containing vessel when it was full, than when it was nearly empty, owing to the difference of pressures at different heights of the surface. The clepsydra, in one of its earlier forms, was used as an astronomical instrument, by the help of which the equator was divided into twelve equal parts, before the mathematical division of a circle was understood; it was deemed of more value than a sun-dial, on account of its dividing the hours of the night as well as of the day. The instrument was employed to set a limit to the speeches in courts of justice, hence the phrases aquam dare, to give the advocate speaking time, and aquam perdere, to waste time. 188 Revista CENIC Ciencias Químicas, Vol. 36, No. 3, 2005. namely, that in any air of whatever force, or can acquire abnormal elas- able, connu de tout le monde, auquel density, but at a given temperature, ticity, there is certainly hope that on pût comparer, & qui comprît tous the pressure varies as the density, powerful devices can be invented les autres degrés de chaleur qui and furthermore, that increases of for operating machines, in the way peuvent être dans l’air que nous pressure arising from equal in- Dr. Amontons has already described respirons” (it was necessary to es- creases of temperature are propor- using the energy of fire. I believe tablish a certain degree of heat, con- tional to the density, this theorem that if all the energy, which is latent stant and invariable, known by ev- was discovered by experiment by in a cubic foot of coal and is dawn eryone, on which we could compare Dr. Amontons The implications of out of it by burning were usefully all other degrees of heat (tempera- the theorem is that if, for example, expended in operating machines, ture) that could be in the air we ordinary air at normal temperature more could be achieved than by a breathe). For Amontons, this degree can hold a weight of 100 lb distrib- day’s labor by 8 or ten men.” of heat necessary for establishing uted over a given surface area, and uniformity in the building of ther- then its temperature is increases Thermometry mometers could well be that of boil- until it can hold 120 lb over the same At the time of Amontons no one ing water, because experience had area and at the same volume, then had yet devised a scale by which taught him that the temperature of when the same air is compressed to temperature could be measured. water remained constant during its half its volume and held at the same Between 1695 and 1703 he pub- boiling, independently of the inten- temperatures, it can support 200 lished several papers4-7 on his im- sity of fire. He then proceed to de- and 240 lb respectively; thus the in- provements of the air thermoscope scribe a thermometer that he had creases of 20 and 40 lb produced by that had been invented by Galileo built that allowed determining the the increase of temperature are pro- Galilei (1564-1642) in 1593. Galileo’s pressure of air that resulted when portional to the density. He asserts, design used the expansion and con- it was heated by boiling water. The moreover, that air, which he calls traction of the air in a tube to instrument consisted simply of a U- temperate, has a pressure approxi- change the level of water, a method tube having one branch open to the mately 3/4 that of air at the tempera- that was vitiated by the fact that the atmosphere and a second much ture of boiling water, or more ex- water was also affected by changes shorter branch ending in a closed actly, 55/73. But in experiments that in air pressure. Amontons remove tip. The whole U tube was filled with I have undertaken I found that the the effect of pressure was replacing mercury, which sealed the air con- warmest air here at the height of water by mercury and adjusting the tained in the bulb. Immersion of the summer, has not the elasticity that height of the latter until the air bulb in boiling water gave a clear Dr. Amontons attributed to “tem- filled a fixed volume. Changing the reading of the (maximum) height of perate” air; in fact I cannot believe temperature of the air in the tube the balancing mercury column. that even at the equator such warm altered the pressure it exerted on Graduation of the scale downwards air ever exists (!!) But I consider the mercury and therefore the in- provided a scale for indicating de- that air hot enough to have a pres- strument should in reality be con- grees of heat below that of boiling sure equal to 3/4 of that of air at boil- sidered a type of barometer. As a water. This scale would be the same ing eater temperature would be consequence, Amontons’s ther- everywhere and could be used to practically intolerable to a living mometer was more accurate than compare the temperature at two dif- creature Accepting this, the tem- Galileo’s, and he was able to use it ferent locations (it was not known perature of boiling water, of the to show that, within the limits of his yet that the boiling temperature of warmest air in summer, and of the instrument, water always boiled at water depended on atmospheric coldest air in winter in this country the same temperature. pressure). are as 6: 4: 3. I will now state how I In his paper of 17024 Amontons In this memoir Amontons also have found these numbers, so that described the “state of the art” of gave detailed instructions on how judgment may be passed on the ac- thermometry pointing out that ther- to fill the thermometer with mer- curacy of my experiments, the out- mometers were marked only be- cury, as well as results of measure- come of which is quite different tween the highest and the lowest ments he made during June and from those of Amontons ” There temperatures observed at a particu- July of 1702. follows a description of the experi- lar region of the earth and that dif- In a following paper5 Amontons mental procedure for measuring ferent instruments located in the compared the reading of his air pressure and temperature. On this same place gave different readings. thermometer with the old instru- basis Bernoulli criticizes the method He then asked a very smart ques- ments based on wine spirit, which employed in England for investigat- tion: Assuming that thermometers he illustrated as shown in figure 1. ing then ratio of the specific gravities did not have the limitations he had Interesting enough, he used a cen- of air and mercury, and concludes: listed, what was the meaning of one tesimal scale to “quantify” the an- ”It is clear from this agreement be- degree of heat in them, what knowl- cient thermometers from 1 to 100 tween the conservation of energy in edge did this degree provide about degrees of heat, corresponding to compressed air and in a body fall- the local climate? His answer to this extreme cold (tres froid) and ex- ing from a certain height that no question was very clear: knowledge treme heat (tres chaud), respec- especial advantage is to be hoped of the particular degree was of no tively. This paper was followed by for from the idea of compressing air advantage, at the most it would in- another one6 converting measure- when designing machines, and that dicate us that one particular year ments reported a few months before the principles displayed in the pre- had been hotter or colder than an- by Étienne François Geoffroy (1672- vious parts of this book are valid other one, but not by how much. For 1731). everywhere. But because it happens this reason he believed that it was The observant reader will notice in many ways that air can be com- necessary to establish a “certain immediately that Amontons’s air pressed naturally without applied degré de chaleur constant & invari- thermometer is actually a thermo- 189 Revista CENIC Ciencias Químicas, Vol. 36, No. 3, 2005.

degr Since degrees in his thermometer were registered by the height of a ès column of mercury, “which the heat de chaleur. was able to sustain by the spring of tres-chaud Congelation du fuif. the air”, it followed that the extreme Grandes chaleurs du 8e climat. cold of the thermometer would be that which reduced the air to have no power of spring. In there must N chaud OUVEAU

A be a lowest temperature beyond NCIEN which air, or any other substance could not be cooled. According to temperé T Amontons, this lowest temperature T HERMOMETRE.

HERMOMETRE. Caves de l’Obfervatoire. represented a greater cold than what we call “very cold’, because his experiments showed that when the

froid “spring of the air” (pressure) at the Congelation de l’eau. boiling point of water was 73 inches, the degree of heat which remained

tres-froid in the air when brought to the freez- ing point of water was still very Grand froid du 8e climat. great, for it could maintain the

I spring of 5.5 inches. Thus Amontons de froid.

s was the first to recognize that the è use of air as a thermometric sub-

degr G iij stance led to the inference of the existence of a zero of temperature. Fig. 1. Comparison between the readings of a wine spirit thermometer with those of Extrapolation of Amonton’s experi- the air thermometer (Amontons, 1703). ments indicated that the air would have no spring left if it were cooled below the freezing point of water, to about 2.5 times the temperature scope, it only allows determining More important, Amontons no- range. On the basis of the 100 de- how much hotter or colder is one ticed that for a particular change in grees difference between the freez- body with respect to another, but temperature, the volume occupied ing and the boiling points of water not the actual value of the tempera- by a gas always changed by the the zero of Amonton’s air thermom- ture. Although this limitation pre- same amount. This led to Amontons’s eter would be located at –240 oC . vented him later from discovering law, which he described in 1699 and Amontons’s brief note presented

Jacques-Alexandre Charles’s (1746- which can be stated today as P1T2 = Johann Heinrich Lambert (1728- 16 1823) law, his new thermometer al- P2T1. It also allowed Amontons to 1777) with a point of departure for lowed him to take the study of gases visualize a temperature at which the extension of this idea. Perfor- a step further than Edmé Mariotte gases contracted to a volume be- mance of more precise measure- (1620-1684) had. yond which they could contract no ments allowed Lambert to fix the Amontons established that if air further. It was this work that even- absolute zero at –270.30 oC, very at atmospheric pressure (30 inches tually led to the concept of absolute close to today’s accepted value of of mercury by his measurements) zero in the19th century (see below). –273.15 oC. In order to increase the and at the freezing point of water Amontons’s air thermometer precision it was necessary to have is held in a constant volume ves- was bulkier, very fragile, and hard a better knowledge of the thermal sel, then if heated to the boiling to use, shortcomings that led to its property of gases, which required point of water its the pressure will demise. more information about the general go up by about 10 inches of mer- nature of gases. In Amontons’s time cury. He also discovered that if he Absolute zero only air had been studied in certain compressed the air in the first Between 1703 and 1704 Amontons detail. place, so that it was at a pressure published several papers5-7 where he of sixty inches of mercury at the reported the phenomena he had Barometer temperature of melting ice, then observed while studying the proper Amontons made a number of if he raised its temperature to way to calibrate an air thermometer. experiments with barometers, pro- that of boiling water, at the same The greatest climatic cold on the posing several solutions which, time adding mercury to the col- scale of units adopted by Amontons however, were never exploited, but umn to keep the volume of air was marked 50 and the greatest which reflect the originality of their constant, the pressure increased by summer heat 58, the value of boil- inventor, who was well ahead of his 20 inches of mercury. In other ing water being 73, and the zero be- time in several fields. His folded words, for a fixed amount of air ing 51.5 units below the freezing barometer of 1688 consisted of a kept in a container at constant point. He noticed that when the number of parallel tubes connected volume, the pressure increased temperature was changed between alternatively at the top and at the with temperature by about 33 % the boiling point of water and am- bottom; the alternating tubes con- from freezing to boiling. This per- bient temperature, equal drops in taining mercury a red liquid. The centage was independent of the temperature resulted in equal de- chief inconvenience of the instru- initial pressure. creases in the pressure of the air. ment lay in the reduction of the 190 Revista CENIC Ciencias Químicas, Vol. 36, No. 3, 2005. variation in the level of the mer- branches of a U-shaped tube and by parties de l’air qui composent cury.17 its dilation it pushed down one of l’atmosphere, & des pores plus In 1695 Amontons gave a de- the mercury columns so that the grands dans le fer que dans le verre.). scription of “un nouveau baromètre other end of the branch formed a Builders of barometers were très simple et portative à l’usage de barometric chamber. aware that the pressure and tem- la mer” (a new simple and portable Amontons was puzzled by the perature of the surroundings sig- barometer, to be used at sea) that did friction present in his cisternless in nificantly affected the reading of not have a mercury reservoir.4 Two his barometer, because ”If we make the instrument. In the beginning types of barometers were described. a simple barometer with a narrow they were unable to explain the rea- One consisted, initially, of a tube tube, the mercury stays up at pre- sons for this anomaly, which prob- narrow enough for the mercury col- cisely the same height as in larger ably included the imperfect vacuum, umn to remain suspended. Amontons tubes, and the movement of the the presence of water vapor, the ex- gradually broadened the tube into mercury has the same regularity pansion of mercury, and the expan- the shape of a slightly conical tube and precision in each, although the sion of glass. Originally the expan- (inverted funnel), closed at the same obstacle which seems to be sion of mercury was attributed to small end and containing a mercury the cause of the inequality in the the expansion of the air it con- column of suitable length, initially one, should also introduce irregu- tained. Amontons was aware that filling the smaller end of the tube. larity into the movement of the mercury itself expanded or contracted The mercury column would become other.” He speculated that the “la depending on the temperature and shorter as atmospheric pressure nature cottoneuse de l’air” (the cot- tried to determine an empirical cor- decreased and longer as it in- ton-like nature of air) was a greater rection for the deviation. In a paper creased. When the tube was in- obstacle to the entry of the air into published in 17049 he reported a verted so that the closed end was narrow tubes than was the viscos- comparison on the relative expan- upwards, the column of mercury ity of the mercury to its motion. It sion of mercury and wine spirit con- would fall in the tube until its length is very possible that the real reason tained in an apparatus consisting of (decreasing as its diameter became for the friction was dirt present in a large bulb and a calibrated col- greater) equalled the barometric the mercury and in the glass tube umn, at different temperatures, height. A scale against which the at its open end. from a “grand froid to a grand position of one end of the column An early attempt to make the chaud” (intense cold to intense was read could give any desired barometer portable was made in heat), using the air thermometer he magnification, depending on the 1688 by Amontons. He proposed had developed previously. Other rate of change of the diameter of the splitting up the height of the mer- scientists did not adopt Amontons’s tube. The lack of reservoir meant cury column into two or more corrections. The measurement of that the barometer could be used at lengths, with either air or a lighter the absolute expansion of mercury sea, where mercury barometers liquid between them. At the same with temperature would be resolved gave unreliable readings because time the scale could be expanded. almost 110 years later by Pierre- the level of the mercury in the res- A critical and final judgment has Louis Dulong (1785-1838) and Alexis- ervoir oscillated with the motion of been made on this barometer by Thérèse Petit (1791-1820) in their the ship. Although this was a clear Daumas:17 “The barometers of award-winning memoir.18 advantage, operation of the instru- Amontons serve as an example of In order to amplify the changes ment was cumbersome: According these short-lived attempts which in reading caused by variations in to Amontons the barometer had to were so faithfully described in ev- external pressure Amontons de- be hung up only when an observa- ery eighteenth century physics text. signed and built a barometer con- tion was being made; then it was to The makers produced them regu- taining a column of a red-tinted oil be laid flat with great care, or in- larly to meet the demand of collec- on top of the mercury column.12 The verted. A drop of mercury fre- tors.” apparatus consisted basically of two quently separated at the larger end An interesting experiment per- large bulbs connected by a U tube, of the column, it could be reunited formed by Amontons was related to the top bulb (A) was located at one with the column by the use of an the height of mercury in a barom- end, hermetically sealed, and the iron wire. In addition, the operation eter.12 Now he built the barometer lower bulb (B) terminated in a long of the instrument was accompanied tube from a musket barrel of me- thin tube connected to the atmo- by a considerable effect of friction. dium caliber (34-1/3 pouces de sphere. The section between the In spite of these shortcomings longuer) welded shut at one end. bottom part of bulb A and the lower Amontons considered that his “ba- After it was set up as a barometer middle part of bulb B was filled with rometer could serve very well at sea, tube, the mercury remaining in it mercury. The red oil was poured on where the others run too great a could be poured out and weighed. top of the mercury and its height risk, for in fact this lack of precision He poured the same amount of mer- varied according to the atmospheric is not considerable enough to pre- cury in a glass tube and to his surprise pressure. vent the amount by which rains and the height achieved as different. winds alter the weight of the air be- These results puzzled him because Telegraph ing appreciable by this barometer, the metal tube was being slowly out Communication at a distance is and we need take no trouble to obtain gassed, even if the weld was really an idea, which has been present in a greater precision, as it is useless.” sound. He concluded that one must one form of another since people The second apparatus described assume the atmosphere to be made have had any information worth was a combination of a barometer of particles of air of various sizes (!!), communicating. Early attempts and an air thermometer indepen- and that iron has large pores than made use of smoke signals, low fre- dent of the atmospheric pressure. glass ( autrement qu’en supposant quency drumbeats, wind instru- Air occupied the top of one of the de l’inéqualité dans la grosseur des ments, and as the technology im- 191 Revista CENIC Ciencias Químicas, Vol. 36, No. 3, 2005.

proved, reflecting mirrors, flags, station may see a signal made by the ered the inconceivable rapidity with and beacon fires. The information next before him; he immediately re- which it is reconverted into water content was low, however, and the peats this signal, which is again re- by cold; and he then contrived a satisfactory transmission of infor- peated through all the intermediate machine for raising water, in which mation by such visual means devel- stations, that it may be seen by per- both of these properties were em- oped very slowly in spite of the pres- sons in the station next after him, ployed. He obtained his patent af- sure put by military requirements. who are to communicate it to those ter having actually erected several Most of the advances were closely in the following station, and so on. machines, of which he gave a de- connected with continuous devel- These signals may be as letters of scription in a book entitled The opment of the optical telescope. The the alphabet, or as a cipher, under- Miner’s Friend, published in 1696, combination of a telescope and a stood only by the two persons who and in another work published in clearly recognizable signaling struc- are in the distant places, and not by 1699. We may add, that much about ture mounted on a hill or tall build- those who make the signals This, the same time Mr. Amontons con- ing and within telescopic sight o a with considerable improvements, trived a very ingenious but intricate similar structure some distance has been adopted by the French, machine, which he called a fire- away, constituted a workable sys- and denominated a telegraphe; and, wheel. It consisted of a number of tem. On May 21, 1684 Robert Hooke from the utility of the invention, we buckets placed in the circumfer- (1635-1703) gave a lecture to the doubt not but it will be soon intro- ence of a wheel, and communicat- Royal Society, entitled On Showing duced in this country. Fas est ab ing with each other by very intricate a Way How to Communicate One’s hoste doceri. [A quote from Ovid, circuitous passages. One part of this Mind, during which he proposed a Met., IV. 428, It is right to learn even circumference was exposed to the scheme in which large boards or from an enemy.] heat of a furnace, and another to a shutters of different shapes could Amontons tried out his optical stream or cistern of cold water. The be hung in a wooden frame to con- telegraph in the presence of the communications were so disposed, vey by their shape different letters Royal family sometime between that the steam produced in the from the alphabet, and viewed from 1688 and 1695. There is no evidence buckets on one side of the wheel a distance by using a telescope. At that anything came of this. Al- drove the water into the buckets on each station a telescope would be though not adopted in Amontons’s the other side, so that one side of placed allowing the person sta- lifetime, his ideas were later refined the wheel was always much heavier tioned at the site to view the com- and put into use. than the other; and it must there- munications of the adjacent site.19 fore turn round, and may execute Hooke’s scheme was never put Fire engine some work. The death of the inven- to practice but other inventors took Between 1696-1699 Amontons tor, and the intricacy of the ma- his basic idea further. In 1690, a vari- developed a primitive fire engine chine, caused it to be neglected.” ant of Hooke’s method, developed that consisted basically of a verti- by Amontons was described in a let- cal wheel with hollow spokes and Friction ter written on November 26, 1695, by rim, fitted with internal valves. It Mankind has used friction be- Abbé Fénelons, the Archbishop of was partly filled with water, and a tween two surfaces in contact since Cambrai, to Johann Sobieski, the fire was lit under one side so that antiquity to produce fire, but under- secretary of the Polish King: the air in that side of the wheel ex- standing of the phenomenon had to “Monseigneur has told me that he panded, and acting through the wait until the pioneering work of was in Meudon and from there sent valves drove the water to the other Leonardo da Vinci, Amontons, John a secret message via windmills to side. The wheel was thus imbalanced Theophilius Desanguliers (1683- Belleville and from there to Paris. and made to rotate. Amontons ac- 1744), Leonard Euler (1707-1783), The answer was given to him simi- tually estimated the duty or the and Charles-Augustin Coulomb larly by signals that were attached work done for the consumption of (1736-1806). Their most important to the wings of the windmill and a given amount of fluid, that his findings can be summarized as fol- read in Meudon with a telescope. engine should have yielded, and lows: (1) the force of friction is di- The signals were letters from the went on to claim that it compared rectly proportional to the applied alphabet, displayed one after the favorably with the cost of power load (Amontons’s first law), (2) the other, at the rate of the slowly turn- from the traditional sources: wind, force of friction is independent of ing mill. As soon as each letter ap- water, and muscle. This approach to the apparent area of contact (Amon- peared, it was recorded in a table by the problem of the heat engine was tons’s second law), (3) Kinetic fric- the observer at the observatory in novel, for it showed that Amontons tion is friction is independent of the Meudon. The inventor [Amontons] understood that general principles sliding velocity (Coulomb’s law). stated that by increasing the dis- were involved, and also that an ide- The concepts of friction have tances, with signals and fire signs alized engine could be used to com- given birth to the science of tribol- one could quickly and cheaply send pute thermo-mechanical pro- ogy (Greek tribos: rubbing), which messages from Paris to Rome; but, cesses.2 concentrates on contact mechanics I believe, he agreed with me, that Evans, in his book about steam of moving interfaces that generally this invention is more a curiosity engines,22 gives the following infor- involve energy dissipation. Tribol- than a practical form of traffic.” mation regarding Amontons’s fire ogy is one of the oldest applied tech- Amontons’s method is also de- engine: “Captain Savary, a gentle- nologies; today it encompasses the scribed in the Encyclopaedia Britan- man of great ingenuity and ardent science fields of adhesion, friction, nica:20 “Let there be people be mind, saw the reality and practica- lubrication and wear. placed in several stations, at such bility of the Marquis of Worcester’s Da Vinci can be considered the distances from each other, that, by project. He knew the great expan- father of modern tribology; he was the help of a telescope, a man in one sive power of steam, and had discov- one of the first scientists to study 192 Revista CENIC Ciencias Químicas, Vol. 36, No. 3, 2005. friction systematically, particularly sures the force necessary for BB it, independently of the mode of for the workings of machines. sliding over AA. movement. That is, AA could be lo- Among the many related phenom- After testing this arrangement cated on top of a horizontal surface, ena he investigated are: friction, wear, in every possible combination (for or hanging from a wheel (pulley). bearing materials, plain bearings, lu- example AA made of copper and BB According to Amontons this was a brication systems, gears, screw jacks, made of iron) Amontons postulated result of the mechanical fact that and rolling-element bearings. the following friction laws: two forces do not act equally except Da Vinci experiments on fric- (a) Que la résistance causée par when they are in the reciprocal ra- tion, done using a horizontal and an le frottement n’augmente et ne tio of their distance to the support- inclined plane, led him to conclude diminuë qu’à proportion des pres- ing point. This is the concept we that friction is proportional to the sions plus o moins grandes suivant know today under the name of le- normal force and independent on que les parties qui frottent ont plus ver rule. the area of contact. He called the ou moins d’étenduë (The resistance Amontons believed that friction proportional factor “friction con- caused by rubbing only increases or was predominately the result of the stant”. Leonardo observed that dif- diminishes in proportion to greater work done to lift one surface over the ferent materials move with differ- or lesser pressure [load] and not ac- roughness of the other, or from the ent ease and suggested that this cording to the greater or lesser ex- deforming or the wearing of the was a result of the roughness of the tent of the surfaces). other surface. When two surfaces material in question; thus, smoother (b) Que la résistance causée par met the teeth of the upper surface materials had smaller frictions. Da les frottements est à peu près la settled into the grooves of the lower Vinci focused on all kinds of fric- même dans le fer, dans le cuivre, surface and to get the upper surface tion, he drew a distinction between dans le plomb, dans le bois, en sliding, a lateral force had to lift the sliding and rolling friction and con- quelque maniere qu’on les varie, teeth out of the grooves (static fric- cluded that the areas in contact lorsque ces matieres sont enduites de tion). This caused a loss of energy, have no effect on friction and that vieux-oingt (The resistance caused which was manifested as a frictional if the load of an object is doubled, by rubbing is more or less the same force: “ nous meditons soigneuse- its friction will also be doubled. Like for iron, lead, copper and wood in ment sur la nature du frotement nous with many others of his works da any combination if the surfaces are trouverons qu’il n’est autre chose que Vinci did not publish his theories on coated with pork fat). l’action par laquelle un corps qui est friction, so he never got enough (c) Que cette résistance est à peu pressé contre un autre est mû sur la credit for them. The only evidence près égale au tiers de la pression surface de celui qu’il touché, & que of their existence is in his vast col- (The resistance is more or less equal comme les surfaces qui frottent les lection of notebooks. According to to one-third of the pressure [load]). unes contre les autres ne peuvent être Truesdell,23 da Vinci wrote: “Every (d) A ces remarques il convient considerées, ou que comme raboteu- body resists in its friction with a encore ajoûter cettte quatrième, que ses & inégales, ou que comme parfai- power equal to the fourth of its ces resistances sont entre elles en tement units, & qu’il est impossible heaviness if the motion is plane raison composées des poids ou dans le premier cas que ces inégali- (slow) and the surfaces dense and pressions des parties qui frottent, tés ne soient parties convexes, & par- polished (clean).” In modern terms, des tem et des vîtesses de leur move- ties concaves, & que les premieres da Vinci asserts here that the fric- ments (to this remarks it is conve- entrant dans les dernieres elles ne tional resistance of a sliding body nient to add a fourth one, that these produisent une certaine résistance is proportional to the normal force, resistances are in the composite ra- lorsqu’on les veut faire mouvoir, puis- and assigned to the coefficient of tio of the weights or pressures of the qu’il faut pour cela qu’elles foûlevent friction the value 1/4. Leonardo did rubbing pieces... and the velocity of ce qui les presse l’une contre l’aitre...” not indicate where he got this figure. their movements). In addition, he explained that Two centuries after Leonardo’s Amontons illustrated his con- that the force to move simulta- discoveries, Amontons21 rediscovered clusions by saying that if plate AA neously a number of weightless the laws of friction while studying the is pressed over plane BB with a blocks piled one on top of the other dry sliding of two plane surfaces. In pressure equal to 30 pounds then it and loaded with an arbitrary weight the introduction of his paper he takes a force to 10 pounds to move is dependent upon the number of wrote: “The great use which all arts are obliged to make of machines is a convincing proof of their absolute necessity Indeed among all those who have written on the subject of moving forces, there is probably not a single one who has given suffi- cient attention to the effect of fric- tion in machines.” Amontons first set of experi- ments was done using the shown in figure 2. AA and BB are two plates made of different materials (copper, iron, lead, wood, coated with pork fat), of different sizes. The pressure exerted by the spring CCC, main- tained at a constant pressure, keeps both plates together. Spring D mea- Fig. 2. Apparatus for measuring friction (Amontons, 1699). 193 Revista CENIC Ciencias Químicas, Vol. 36, No. 3, 2005.

sliding faces. The resistance at each that presses the two surfaces to- atom contact takes place. The adhe- sliding face is proportional to the gether. The coefficient of proportion- sion concept of friction for dry friction, weight applied and the total resis- ality, m, or coefficient of friction, de- already proposed by Desanguliers, tance is equal to this force multiplied pends on the materials and whether was applied with great success by by the number of sling surfaces. the body is at rest or in motion. Bowden and Tabor to metal-metal Amontons then analyzed the The three frictions laws were at- interfaces. Bowden and Tabor25 friction that takes place between a tributed initially to dry friction only, showed that the force of static fric- pulley and a braided cord and pre- but it has been well known since tion between two sliding surfaces is pared a table that allowed a rapid ancient times that lubrication modi- strongly dependent on the real area calculation of the force needed to fies the tribological properties sig- of contact. Their work led to the as- raise a weight as a function of the nificantly (Amontons’s experiments perity contact theory of friction. In radius of the pulley, the weight to themselves were carried using sur- adhesive wear, asperity junctions be lifted, and the number of threads faces lubricated by pork fat). How- plastically deform above a critical in the cord. ever, it was not until the 1880s that shear strength, which depends on While Leonardo tested static Nikolai Pavlovich Petrov (1842- the adhesive forces of the two sur- friction Amontons dealt with ki- 1912) and Osborne Reynolds (1836- faces in contact. Assuming during netic friction, although from this 1912) studied lubrication experi- a frictional sliding process a fully writings it is not clear that he was mentally. Both, independently, plastic flow situation of all asperi- aware of the difference between the recognized the hydrodynamic na- ties, friction is found to change lin- two phenomena. ture of lubrication and introduced early with the applied load as de- As quoted by Frank Philip Bowden a theory of fluid-film lubrication. manded by Amontons’s first law.27 (1903-1968) and David Tabor,26 the Analytic results and experiments in French Académie des Sciences ultra-high vacuum have indicated BIBLIOGRAPHY received with scepticism the redis- that the static friction between two 1. Fontenelle B.B., Éloge de M. Amon- covery of da Vinci’s laws by Amontons, clean crystalline surfaces should tons, Histoire Acad. Royale Sci., 150- which he repeated during the almost always vanish yet macro- 154, 1705. 2. Cardwell, D.S.L., From Watt to presentation of his fire engine (see scopic objects always exhibit static 27 Clausius, Cornell University Press, above): “Dans le Discours que fit M. friction. As stated by He et al., Ithaca, 18-21, 1971. Amontons sur son Moulin à feu, il there is always some kind of third 3. De Sassure H.B., Essai sur l’Hygro- avança seulement en passant que body present between two surfaces métrie, Bardel and Maiget, Geneva, 1783. c’étoit une erreur de croire, comme because any surface exposed to 4. Amontons G., Discours sur Quelques l’on fait communément, que le frot- ambient air acquires an adsorbed Propriétés de l’Air, & le Moyen d’en tement de deux corps qui se meuvent layer of hydrocarbons and other Connoître la Température dans Tour les Climats de la Terre, Mém. Acad. en s’appliquant l’une contre l’autre, small molecules that is several na- Royale Sci., 155-174, 1701. soit d’autant plus grand, que les sur- nometers thick. 5. Amontons G., Le Thermometre faces qui frottent sont plus grandes. At first look Leonardo and Réduit à Une Measure Fixe & Il dit qu’il avoit reconnu par expe- Amontons’s laws appear absurd be- Certaine, & les Moyen d’y Rapporter rience que le frottement n’augmente cause intuitively one would expect les Observations Faites Avec les An- que selon que les corps sont presses the friction force to be proportional ciens Thermometres, Mém. Acad., l’un contre l’autre, & charges d’un to the area of contact. Bowden and Royale Sci., 50-56, 1703. plus grand poids. Cette nouveauté Tabor resolved this paradox in 6. Amontons G., Remarques sur la Table 25 des Degrés de Chaleur, Mém. Acad. causa quelque étonnement à la Aca- 1939 when they distinguished be- Royale Sci., 202-212, 1703. démie”. tween the real area of contact and 7. Amontons G., Expériences sur la Euler was the first one to distin- the geometric visible area of con- Raréfaction del’Air, Mém. Acad. guish between static and kinetic tact. The real area of contact is only Royale Sci., 119-124, 1704. friction, because he found that it is a fraction of the visible area of con- 8. Wisniak J., Development of the Con- not possible to cause a slow motion tact. All experiments lead to the cept of Absolute Zero Temperature, by slowly increasing the angle of an conclusion that friction is propor- Educ. Química, en revisión (2004). 9. Amontons G. Que Toutes les Baro- inclined plan. Coulomb did the most tional to the real area of contact, as metres Mém. Acad. Royale Sci., systematic work on friction; he ex- intuitively expected. 164-172, 1704. amined the influence of a large Adhesion is a term relating to 10. Amontons G., Discours sur les number of variables on the phenom- the force required to separate two Barometres, Mém. Acad. Royale Sci., enon. Coulomb confirmed Euler’s bodies in contact with each other. In 271-278, 1704. statement experimentally, after 1734 Desanguliers proposed adhe- 11. Amontons G., De la Hauteur du measuring kinetic friction at differ- sion as an element in the friction Mercure dans les Barometres, Mém. Acad. Royale Sci., 229-236, 1705. ent speeds and finding that friction process, a hypothesis that appeared 12. Amontons G., Suite des Remarques is independent of the velocity. to contradict experiments because sur la Hauteur du Mercure dans les Coulomb’s conclusion that once of the independence of friction on Barometres, Mém. Acad. Royale Sci., movement has commenced, the the contact area (Amontons’s sec- 267-272, 1705. friction force is independent of the ond Law). The contradiction be- 13. Amontons G., Barometres Sans velocity, was added as an extension tween the adhesive issue and Amon- Mercure a l’Usage de la Mer, Hist. to Amontons’s second law. For sev- tons’s second law cleared up by the Acad. Royale Sci., 49-54, 1705. eral centuries after Amontons’s introduction of the concept of the 14. Amontons G., Remarques et Éxperien- ces Physiques sur la Construction work, scientists believed that fric- real area of contact. The real area d’Une Nouvelle Clepsydre, J. Jombert, tion was due to the roughness on of contact is made up of a large Paris, 1695. the surfaces, and expressed it math- number of small regions of contact, ∝ µ 15. Bernoulli D., Hydrodynamica, sive de ematically as F L where F is the in the literature called asperities or viribus et motibus fluidorumcom- frictional force and L the normal lad junctions of contact, where atom-to- mentarii. Opus academicum ab auc- 194 Revista CENIC Ciencias Químicas, Vol. 36, No. 3, 2005.

tore, dum Petropoli ageret, congestum; 19. Beauchamp K., History of Telegraphy, 23. Truesdell C., Essays in the History of Me- J.R. Dulseckeri, 1738. Translated and The Institution of Electrical Engi- chanics, Springer-Verlag, Berlin, 1968. reprinted as Hydraulics, Dover Pub- neers, London, 2001. 24. Amontons G., De la Resistance Causé lications, New York, 200-204, 1968. 20. Telegraph, entry on the Encyclo- dans les Machines, Mém. Acad. 16. Lambert J.H., Pyrometrie oder von paedia Britannica, London, 8, 334- Royale Sci., 206-227, 1699. Maase des Feuers und Wärme, Bey 337, 1797. 25. Bowden F.P., Tabor D., The Area of Haude und Spener, Berlin, 1779. 21. Amontons G., Moyen de Substituer Contact Between Stationary and Be- 17. Daumas M., Scientific Instruments of Commodement l’Action du Feu a la tween Moving Surfaces, Proc. Roy. the Seventeenth and Eighteenth Cen- Force des Hommes et des Chevaux, Soc., A169, 391-413, 1939. turies and Their Makers, B.T. Mém. Acad. Royale Sci., 112-116, 1699. 26. Bowden F.P., Tabor D., The Friction Batsford, London, 1972. 22. Evans O., Young Steam Engineer’s and Lubrication of Solids, Oxford 18. Dulong P., Petit, A. T., Recherches Sur Guide, printed for the author by Fry University Press,Oxford, 1958. la Mesure des Températures et Sur les and Kammerer, Philadelphia, 1805. 27. He G., Müser M.H., Robbins M.O., Lois de la Communication de la Chaleur, Reprinted from the first edition by Adsorbed Layers and the Origin of Ann. Chim. Phys., 7, 113-154, 1818. the Oliver Evans Press, 1990. Static Friction, Science, 1650-1653, 1999.

CONVOCATORIA 5. CONGRESO INTERNACIONAL DE EDUCACION SUPERIOR "UNIVERSIDAD 2006" 13 al 17 de febrero del 2006 en el Palacio de Convenciones de La Habana. ‘’La Universalización de la Universidad por un mundo mejor’’

TEMAS CENTRALES & Experiencias en la universalización de la universidad. & Desarrollo y perspectivas de la educación superior por un mundo mejor. & El perfeccionamiento de la pedagogía y la didáctica de la educación superior. & La educación de posgrado y el desarrollo de la sociedad. Su pertinencia e impacto. & Aportes concretos de las universidades para el desarrollo sostenible. & Las tendencias y desafíos actuales de la internacionalización de la educación superior. & Políticas y estrategias sobre la evaluación de la calidad y acreditación en la educación superior. & Tecnologías, modelos, realidades y perspectivas de la educación a distancia. & Retos y perspectivas de la investigación científica en las universidades. & Las tecnologías de la información y la comunicación en la transformación de los procesos universitarios. & La extensión universitaria como una opción viable por un mundo mejor. & La práctica y la investigación en la formación universitaria en Turismo. & Papel de las organizaciones sindicales y estudiantiles en las universidades por la construcción de un mundo mejor. TALLERES Y SIMPOSIOS & Simposio de Universalización de la Universidad. & VIII Taller Internacional ‘’La Educación Superior y sus Perspectivas’’. & VIII Junta Consultiva sobre el Postgrado en Iberoamérica. & VII Taller Internacional de Educación a Distancia. & VIII Taller de Extensión Universi- taria. & V Taller de Pedagogía de la Educación Superior. & V Taller ‘’Universidad, Medio Ambiente y Desarrollo Sostenible’’. & V Simposio ‘’Universidad, Ciencia y Tecnología’’. & III Taller Internacional de Evaluación de la Calidad y Acreditación en la Educación Supe- rior. & III Taller de Internacionalización de la Educación Superior. & II Conferencia ‘’Retos de la Educación Superior frente al Desarrollo Turístico’’. 195