Abstract: A machine which allows the moments of inertia of an appliance to be measured relative to two axes without the configuration of the machine to be modified in any way. This machine comprises a fixed horizontal plate and an oscillating table mounted with a vertical shaft so as to be capable of oscillation about the longitudinal axis of said rotary shaft. The oscillating table is supported on the fixed plate by means of a plurality of pneumatic support devices spaced from and arranged symmetrically around the rotary shaft, the latter extending through the fixed plate and being centered in the central opening in the fixed plate by radial bearing elements, e.g. gas bearing elements.