In these days of additive-containing lubricating oils, it is becoming usual to think that the additives are more important than the base oil, in fact it is possible that we shall eventually lubricate with additives whilst the ‘Lubricating Oil’ may only be a carrier to take the additives to the bearings. Temperatures which may be reached by bearings operating in the immediate vicinity of atomic power reactors and subjected to temperatures almost beyond imagination today, as well as to atomic radiation, may well need to be ‘tailor-made’ for the job and may not resemble present oils and greases in any way.