This document describes a project designed to explore the possibilities of children's learning in mechanics. The principle of the lever, one example of a simple machine, was used in the form of a balance toy. The apparatus was set up as a game in a specially devised learning center. The children made non-verbal predictions as to which way the bar would tilt when various weights were placed at either end. After completion of a pilot study, 22 kindergarten children were chosen as subjects. Half of the groups received orientation to provide a clear replicable procedure for introducing the materials. A criterion test was developed. The apparatus was then placed in the classroom with no restrictions as to who could use it or for how long. Observers noted the children's behavior, recording anecdotal information and use of the balance. On the fourth day, all children were posttested. Results indicated that both groups (with or without orientation) performed similarly on the posttest. Discussion centered on the use of learning centers in open classrooms for facilitating learning, and the possibilities of teaching scientific principles to young children. (DP)