A black and white photo of two men, Dr. Prater and Dr. Wei, working on a mathematical model of a petroleum molecule. There’s a chalkboard in the back with some equations. On the back of the photo, there’s an inscription that reads, "Dr. Dwight Prater (seated) and Dr. James Wei with their 3-dimensional, mathematicalmodel which shows exactly what happens to petroleum molecules during refining. Photo used in June 1961 Mobil advt: "What Does a Chemical Reaction Look Like?"" In pencil, it reads, "Hist File: New Jersey - Research in Paulsboro."