Print, Photographic

Black and white photographic print depicting George McCallister standing at a hopper being filled with dust at the Champion Spark Plug Co.
Caption on verso reads, "Dept. 2 - 2nd floor. Method of removing the dust from the large vacuum mixing tanks. Instead of showing the dust going into one of the 3M# tanks, it is shown going into one of the rectangular hoppers now used in Dept 4 for feeding the presses in Dept 3 and also showing the dust going into one of the round hoppers which are used to feed the mill ball presses. George McCallister, Foreman, in this photograph."
Dated 5-7-1949