Abstract: A device for damping a perpendicularly oscillating primary mass comprising a perpendicularly oscillatory reference mass supported by a piston in a pressure fluid chamber of an adjusting member. The pressure in the fluid chamber compensates for the weight of the reference mass and varies as a result of reference mass oscillation. Upon reduction of the prevailing pressure the fluid chamber receives fluid from a first pressure line through an automatic inlet valve, and upon increase of the prevailing pressure the fluid chamber emits fluid into a first return line through an automatic outlet valve, so as to impose on the adjusting member an oscillatory movement tending to reduce the vertical movement of the primary mass. The adjusting member forms a second piston in a follow-up cylinder to which the primary oscillating mass is connected.