Print, Photographic

Black and white photographic print mounted on fabric depicting a pile of rocks outside the Champion Spark Plug Co.
Caption reads: Photograph 2-A
Sillimanite (Andalusite) storage pile at the Detroit plant. The pile is built systematically by placing the carloads in very narrow parallel layers, of equal thickness. As the pile is used, cuts are taken across the end of the pile at right angles to the parallel rows, and so each withdrawal contains an equal amount of every carload in the pile. Hence the storage pile represents a uniform supply of raw material which lasts about a year.