| +------------+ +-----------+ +--------------+ | Gas & Fuel | | Neutral | | | | Oil Stock | | Oil Stock | | Asphalt +------------+ +-----------+ +--------------+ | | Paraffin Wax | Clay +--------------+ Percolation | +----------+---+ | | Asphalt | +-------------+ | Neutral Oil | +-------------+ DIAGRAM SHOWING THE PRODUCTS OF PETROLEUM BY FRACTIONAL DISTILLATION I will first deal with the method of refining known as the “straight” process, or the process which does not involve “cracking.” At one time, the refiner had to consider the saleability of his refined products before he commenced to refine them, but to-day, with the perfect system which prevails for the handling of huge quantities of refined products, and the transporting of them to the most distant markets, the one desire of the refiner is, naturally, to secure from his treatment of the crude oil, as many refined products as possible, always keeping an eye on the production of the largest quantities of the higher priced products than upon those which are of low value. The process of refining to be applied to any particular oil naturally depends upon its composition as shown by analysis. It may be that the crude oil to be treated, apart from containing a small percentage of distillates with a low boiling point (motor spirit), is principally made up of residues of little value except as fuel, or, on the other hand, it may be that the crude oil is of high quality and contains all possible products. In the former case, the process of distillation is brief, and the plant inexpensive, as compared with the lengthy process of full refining necessitated in the latter case.