Résumé
This paper deals with the mechanical properties of naturally aged wood and thermally treated wood wood. Naturally aged wood samples delivered from Japanese historical buildings are precise dating with using both radioactive carbon dating 14C and dendrochronology methods. And Hinoki (Chamaecyparis obtusa Endl.) specimens cut out from recently felled down and naturally dried were heated at 90-180 °C as accelerated aging treatment. The general trends in rigidity, Young's modulus and rupture energy might be similer, quantitative differences are likely to be observed between the various kinds of modifications induced by age.