AMONTONS, (GUILLAUME). - THE INVENTION OF THE AIR PRESSURE THERMOMETER.

Discours sur quelques proprietez de l'air, & le moyen d'en connoître la temperature dans tous les climats de la terre.

(Paris, Jean Boudot, 1704). 4to. Without wrappers. Extracted from "Mémoires de l'Academie des Sciences. Année 1702". Pp. 155-174 a. textillustrations.

First appearance of this paper in which Amontons describes his invention, construction and function of his air thermomer. He thus improves on Gallileo's design by using air pressure instead of volume. The paper is the earliest study in this field, and Amontions concludes "that unequal masses of air under equal weights invcrease equally the force of their spring for equal degrees of heat" Fifteen years later Gay-lussac performed the same experiments with better technique and results - the Gay-Lussac laws.The paper "contains Amontons' account of the first thermometer with which temperature was measured by the pressure of air."(Magie "A Source book in Physics", pp. 128 ff.).

"His first scientific production was a Hygrometer in 1687....The other was an air thermometer independent of the atmospheric pressure. Air occupied the top of one of the branches of a U-shaped tube, and by its dilation it pushed down one of the mercury columns so that the other end ofthe branch formed a barometric chamber."(DSB I, p. 138 a).

Parkinson "Breakthroughs", 1702 M).

Order-nr.: 44385