Gov. Mifflin, of Pennsylvania, lived and owned a fine estate in Mifflin county, and in which county was discovered from time to time, any quantity of black rock, as the farmers commonly called the then unknown anthracite. Of course, the old governor knew something about stone coal, and had a slight inkling of its character. At hours of leisure, the governor was in the habit of experimenting upon the black rocks by subjecting them to wood fire upon his hearths; but the hard, almost flint-like anthracite of that region resisted, with most obdurate pertinacity, the oft-repeated attempts of the governor to set it on fire. It finally became a joke among the neighboring Pennsylvania Dutch farmers, and others of the vicinity, that Gov. Mifflin was studying out a theory to set his hills and fields on fire, and burn out the obnoxious black rock and boulders. But, despite the jibes and jokes of his dogmatical friends, the old governor stuck to his experiments, and the result produced, as most generally it does through perseverance and practice, a new and useful fact, or principle. One cold and wintry day, Gov. Mifflin was cosily perched up in his easy-chair, before the great roaring, blazing hickory fire, overhauling ponderous state documents, and deeply engrossed in the affairs of the people, when his eye caught the outline of a big black rock boulder upon the mantle-piece before him--it was a beautiful specimen of variegated anthracite, with all the hues of the rainbow beaming from its lacquered angles. The governor thought "a heap" of this specimen of the black rock, but dropping all the documents and State papers pell-mell upon the floor, he seized the piece of anthracite, and placing it carefully upon the blazing cross-sticks of the fire, in the most absorbed manner watched the operation. To his great delight the black rock was soon red hot--he called for his servant man, a sable son of Africa, or some down South Congo-- "Isaac." "Yes, sah, I'se heah, sah." "Isaac, run out to the carriage-house, and get a piece of that black rock." "Yes, sah, I'se gone." In a twinkling the negro had obtained a huge lump of the anthracite, and handing it over to the governor, it was placed in a favorable position alongside of the first lump, and the governor's eyes fairly danced polkas as he witnessed the fact of the two pieces of black rock assuming a red hot complexion. "Isaac!" again exclaimed the governor. "Yes, sah." "Run out--get another lump." "Yes, sah." A third lump was added to the fire; the company in the governor's private parlor was augmented by the appearance of the governor's lady and other portions of the family, who, seeing Isaac lugging in the rocks, came to the conclusion that the governor was going "clean crazy" over his experiments. It was in vain Mrs. Mifflin and the daughters tried to suspend the functions of the "chief magistrate," over the roaring fire.