In the compact anti-vibration mounting described, inertia is provided by a 10 kg lead block carrying the instrument (a mirror galvanometer in the example described), whilst the elastic mounting and associated damping is provided by the simple expedient of `floating' the slab on a `cradle' consisting of a lightly inflated balloon-type cycle inner tube wrapped round the slab in a particular manner. The inner tube can also be made to provide `built-in' anchorage for the mounting in any equipment in which the instrument is to be incorporated.