Strong Box Prediction Chest. Portland: Gem Magic Mfg., ca. 1980s. The performer invites a spectator to open the box revealing the performer?s prediction of a headline, number, or virtually any other piece of information. Famously used by David Copperfield for his televised Superbowl 35 prediction. Crafted by John Pomeroy in wood and brass with matching brass screws. From a limited production run of approximately 12. 6 ? x 6 ? x 9?. Age-related patination to brass including scuffing and light oxidation, otherwise good overall.