ABSTRACT
The barometric formula, relating the pressure p(z) of an isothermal, ideal gas of molecular mass m at some height z to its pressure at sea level, p 0, is discussed. Three mathematical derivations of the formula are given together with three generalizations, like nonisothermal atmosphere, nonconstant gravitational field, and Earth rotation. A generalization of the barometric formula for negative heights is discussed. Some related historical aspects are also given.
