A device for use in the control of mechanical forces. The device comprises first and second terminals for connection, in use, to components in a system for controlling mechanical forces and independently moveable. Hydraulic means are connected between the terminals and contain a liquid, the hydraulic means configured, in 4 use, to produce upon relative movement of the terminals, a liquid flow along at least two flow paths. The liquid flow along a first flow path generates a damping force proportional to the velocity of the liquid flow along the first flow path, and the liquid flow along a second flow path generates an inertial force due to the mass of the liquid, the force being substantially proportional to the acceleration of the liquid flow along the second flow path, such that the damping force is equal to the inertial force and controls the mechanical forces at the terminals.