Amontons, Guillaume

Amontons Guillaume A. (1663-1705) Fr. phys., concept of absolute zero thermodynamic temperature at which gas pressure vanishes, constructor of thermometers and barometers Ampere Marie Andre (1775-1836) Fr. phys., founder of electrodynamics (Ampere s Law), inventor of galvanometer (book Theorie des phenomenes electro-dynamiques 1826)... 

The first recorded systematic studies on static friction have been carried out by Leonardo da Vinci.1 He had already stated that friction does not depend on the contact area and that doubling the weight doubles the friction. The most important empirical law found for describing friction was published in 1699 by Guillaume Amontons.2 Like da Vinci he measured the force Ff required to slide a body over a solid surface at a given load Fp (Fig. 11.1). The load is usually the weight of the body but it can also contain an additional external force pushing the body down. Amonton found that the frictional force is proportional to the load and does not depend on the contact area. For example, in Fig. 11.1 the loads F[ = Fp are equal, then the frictional forces are also equal Fp = Fp. In other words the coefficient of friction p defined by... 

Friction is the tangential resistance offered to the sliding of one solid over another, due to dry friction. Friction is an apparently simple phenomenon with very complex mechanisms that take place on a variety of length scales, from atomic to nano and up. The study of friction is part of the engineering-scientific discipline of tribology,3 which is the scientific study of friction, wear, and lubrication (6). It was Leonardo da Vinci (1452-1519) who discovered the first two laws of friction, namely, that the area of contact has no effect on friction and that friction is proportional to the load. These two laws were rediscovered later by Guillaume Amontons (1663-1705), and later Charles-Augustin Coulomb (1736-1806), added the third law ... 

He turned his interests from steel to temperature, and in 1730 he presented to the Paris Academy his study A Guide for the Production of Thermometers with Comparable Scales. He wanted to improve the reliability of thermometers based on the work of Guillaume Amontons, though he appears not to be familiar with Daniel Gabriel Fahrenheit s earlier work. 

Vo is the initial volume of a certain amount of gas at, for example, a temperature of 0 °C (ice point), and is its temperature on the Celsius scale. A graphic or analytic extrapolation of the isobars F(5) (Fig. 10.2) leads to an important conclusion AU the linear functions F(5) belonging to different constant pressures, will intersect with the temperature axis at about 3= —267 °C (actually at 273.15 °C, as later measurements have shown), independent of the type of gas and amount of substance. The experiments carried out by Charles and Gay-Lussac were therefore a further indication of the existence of an absolute zero point of temperature. This had already been postulated in 1706 by Guillaume Amonton. It seemed, therefore, reasonable to introduce a new temperamre scale and to measure temperature from this point because volume is never negative. This is how we arrive at the so-called absolute temperature scale. We were already introduced to this scale in Sect. 3.8 (but there we did not use the ice point but the more convenient triple point of water to fix the scale). Further, it also becomes clear that Eq. (10.2) is an example of a... 

Prove the following statement the pressure of a given amount of gas at a fixed volume is proportional to the absolute temperature. This is sometimes called Amontons s law. In 1702 Guillaume Amontons constructed a thermometer based... 

The friction law. The first works on fiiction are those of Leonardo da Vinci (/) at the beginning of the XVI century and Guillaume Amontons (2) in 1669, but the taldng into account of the influence of the sur ce prop es of soUds in contact is due to Charles Augustin de Coulomb (3). In 178S he writes the famous rdationship, which is known today as Coulomb s fiiction law, connecting the fiiction reastant force Tto the normal load applied N ... 

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