Determines the tensile strength of fresh and archaeological bovine bone perpendicular to its long axis indirectly by the diametrical compression of disc-shaped specimens. Measured values of strength and bulk density ranged from ~ 60 MPa and ~ 2.0 g cm^-3 for the modern samples to only ~ 4 MPa and 0.8 g cm^-3 for archaeological bone in the poorest states of preservation, respectively. Two mechanisms may be involved in the diagenetic degradation of bone. The initial loss of strength derives from the hydrolysis of collagen although the precise detail of the attack is unknown. This is followed by predation of tunneling microorganisms leading to an increase in pore volume and further loss of mechanical strength.