The primary composition around the knee from EAS e.m., GeV and TeV muon data

We present the results of the studies of the cosmic ray primary composition around the knee of the spectrum performed by EAS-TOP (2005 m a.s.l, 105 m2 collecting area) and MACRO (963 m a.s.l., 3100 m w.e. of minimum rock overburden, 920 m2 effective area) at the National Gran Sasso Laboratories. The used observables are the shower size (Ne) measured by EAS-TOP and the muon number (Nµ) recorded by MACRO. The results support a primary composition becoming heavier at the knee of the primary spectrum. The observables used in the analysis are the results of secondary particles produced in the early stages of the shower development and in kinematic region quite different from the one relevant for the usual Nµ - Ne studies.