The Los Alamos National Laboratory is developing a program in large-volume testing of rocks. One part of this program is the measurement of size effects on the constitutive properties of rock. The other part is the development of models to explain and predict these effects. We use a unique 44-MN hydraulic press to load large specimens to failure, while measuring stress-strain behavior, failure strength, and acoustic emission. In this paper, results of stress-strain measurements taken on a single sample of ''Texas Pink'' granite are reported. We took two sets of data with gauge lengths of 0.3 and 10.0 cm. We also discuss existing models of size effect on strength and conclude that a stochastic model is needed to replace existing empirical deterministic ones. Estimates of initial crack abundance together with our simple model of failure explain the variation of strength with size reported by some investigators.