A black and white photo of a man using a machine called the solvent dewaxing filter. On the back of the photo there’s an inscription that reads, "43. Solvent Dewaxing Filter, Dewaxing is an essential operation in the preparation of many types of lubricating oils. Wax-bearing oils turn solid at relatively high temperatures, but when the wax is removed the oils are fluid even under frigid conditions. All Mobiloils are de-below zero. Thus, even during the severest winter weather, the Mobiloils provide free-flowing lubrication to all moving parts the instant the engine or machine is started. The laboratory filter illustrated is one of the many used in a recent five-year laboratory study of modern solvent dewaxing methods. In operation, a wax-bearing oil is mixed with about four times its volume of a special chemical solvent which causes the wax present in the oil to precipitate. This mixture is chilled to temperatures as low as 40 degrees F. below zero, which causes complete crystallization of the wax. The chilled mixture is then pressed through a filter at the same temperature. The wax is then passed through a filter at the same temperature. The wax is recovered as a solid, while the valuable wax-free oil is recovered by by distilling the filtered mixture to remove the solvent. The operation shown is being conducted in a cold room at 30 degrees F. below zero, and was photographed through a window. Early in 1937, all of our lubricating oil refineries were equipped with solvent dowsing process chosen on the basis of a five-year laboratory study. These plants cost several million dollars and their operation results in a maximum recovery of the desirable lubricant fractions with virtually complete ominiation of the undesirable wax. (Research and Development Division)" There’s a stamp that reads, "Socony-Vacuum Oil Company, Inc., Advertising Department, 26 Broadway, New York, N.Y."