Therefore, it became doubly important to arrange for an adequate and continuous supply of benzol. Edison made a study of the methods and processes of producing benzol and then made proposals to various steel companies to the effect that he would, with their permission, erect a benzol plant at their coke ovens, operate the same at his own expense, and pay them a royalty for every gallon of benzol, toluol, xylol, or solvent naphtha taken from their gases. Such arrangement would not only meet his requirements, but at the same time would give the steel companies an income from something which they had been allowing to pass away into the air. He succeeded in making arrangements with two of the companies--namely, the Cambria Steel Company at Johnstown, Pennsylvania, and the Woodward Iron Company, Woodward, Alabama. Ordinarily, it requires from nine to ten months to erect a benzol plant, but before making his proposal to the steel companies Edison had worked out a plan for erecting a practical plant within sixty days, and had laid it out on paper. He was sure of his grounds, because from his vast experience he knew where to pick up the different pieces of apparatus in various parts of the country. The contract for his first benzol plant at Johnstown, Pennsylvania, was signed on January 18, 1915, and the actual work was begun an hour after the contract was signed, with the final result that in forty-five days afterward the benzol plant was completed and commenced working successfully. The second plant, at Woodward, Alabama, was completed within sixty days after breaking ground, the two weeks difference in time being accounted for by the fact that Woodward was farther away from the base of supplies and there were delays in railroad transportation of materials. Being sure, through these contracts, of a continuous supply of benzol, Edison designed a plant for making aniline oil. By working gangs of men day and night, the erection of this plant was completed in forty-five days. The capacity of the plant, four thousand pounds per day, was fully contracted for by anxious manufacturers long before the machinery was in place.