Assuming that the general direction of profitable developments would be north-east and south-west, Mr. Prentice surveyed a line from Venango county through West Virginia, Kentucky and Tennessee. This idea, really the foundation of “the belt theory,” he spent thousands of dollars to establish. Personal investigation and careful surveys confirmed his opinion, which was based upon observations in the Pennsylvania fields. The line run thirty years ago touched numerous “springs” and “surface shows” and recent tests prove its remarkable accuracy. On this theory he drilled at Mount Hope and Foster, opening a section that has produced several-million barrels of oil. C. D. Angell applied the principle in Clarion and Butler counties, mapping out the probable course of the “belt” and leasing much prolific territory. His success led others to adopt the same plan, developing a number of pools in four states, although nature’s lines are seldom straight and the oil-bearing strata are deposited in curves and beds at irregular intervals. [Illustration: FREDERIC PRENTICE.] In company with W. W. Clark of New York, to whom he had traded a portion of his West-Virginia lands, Mr. Prentice secured a quarter-interest in the Tarr farm, on Oil Creek, shortly before the sinking of the Phillips well, and began shipping oil to New York. They paid three dollars apiece for barrels, four dollars a barrel for hauling to the railroad and enormous freights to the east. The price dropping below the cost of freights and barrels, the firm dug acres of pits to put tanks under ground, covering them with planks and earth to prevent evaporation. Traces of these storage-vats remain on the east bank of Oil Creek. Crude fell to twenty-five cents a barrel at the wells and the outlook was discouraging. Clark & Prentice stopped drilling and turned their attention to finding a market. They constructed neat wooden packages that would hold two cans of refined-oil, two oil-lamps and a dozen chimneys and sent one to each United-States Consul in Europe. Orders soon rushed in from foreign countries, especially Germany, France and England, stimulating the erection of refineries and creating a large export-trade. Clark & Summer, who also owned an interest in the Tarr farm, built the Standard Refinery at Pittsburg and agreed to take from Clark & Prentice one-hundred-thousand barrels of crude at a dollar a barrel, to be delivered as required during the year. Before the delivery of the first twenty-five-thousand barrels the price climbed to one-fifty and to six dollars before the completion of the contract, which was carried out to the letter. The advance continued to fourteen dollars a barrel, lasting only one day at this figure. These were vivifying days in oleaginous circles, never to be repeated while Chronos wields his trusty blade.