The main features of the C.E.R.N. Intersecting Storage Rings (I.S.R.) are reviewed, together with results obtained in 1971 and 1972 on elastic scattering and total cross-sections. The main result is a 10% increase of the total proton-proton cross-section in the I.S.R. energy range. The simplest picture of high energy proton-proton scattering which emerges from this and the other data, is briefly discussed.