Law stated by Jacques Charles in 1787, and
independently by Joseph Gay-Lussac
(1778-1850) in 1802, which states that the
volume of a given mass of gas at constant
pressure is directly proportional to the
absolute temperature: it increases by 1/273
of its volume at 0 degrees C for each degrees
C rise of temperature. This means that the
coefficient of expansion of all gases is the
same. The law is only approximately true and
the coefficient of expansion is generally
taken as 0.003663 per degrees C.