Among the observed variety of the natural phenomena reflected in experimental results, there are just a few physical features offering a view of a given fragment of the mosaic of physical laws in its entirety. One such remarkable fundamental feature is R, the ratio of the inclusive cross section of electron–positron annihilation into hadrons to the cross section of muon pair production in the Born approximation. We discuss experiments on measuring the R(s) ratio in the energy range 1.84–3.72 GeV.