Portable object provided with a device for measuring atmospheric pressure

Portable object equipped with a mechanism (1) for measuring atmospheric pressure, the atmospheric pressure measuring mechanism (1) comprising an atmospheric pressure sensor (2) whose geometric dimensions vary as a function of atmospheric pressure fluctuations, the variations in geometric dimensions of the atmospheric pressure sensor (2) being applied to a device (32; 32') for displaying a barometric trend connected to the atmospheric pressure sensor (2) via a clutch mechanism (34; 34') actuated by a user, the clutch mechanism (34; 34') being able to be switched between a first position in which the kinematic linkage between the atmospheric pressure sensor (2) and the device (32; 32') for displaying the barometric trend is interrupted, and a second position in which the device (32; 32') for displaying the barometric trend is kinematically coupled with the atmospheric pressure sensor (2).