MASON AND DIXON'S LINE (ante) originated in the difficulties which occurred in tracing the boundary line of a tract of land granted to William Penn in 1681. This land lay w. of the Delaware and n. of Marylaud, and a part of its southern boundary was defined to be " a circle drawn at 12 m. distant from Newcastle northwards and westwards into the beginning of the 40° of northern latitude." Later, Penn received another grant, and, his agent being unable to agree with the authorities in America as to the just boundary, he came to this country himself in 168'2 to establish his claim and tate possession of his land. He was opposed by lord Baltimore, the matter was referred to the committee of trade and plantations, a change in the reigning, monarch of England took place, and it was not until 1760 that the final deed was issued to the heirs of Penn, closing the controversy. But even then the question of surveying the disputed territory with a view of defining the boundary-line opened new disagreement; and it was to arrange this that Charles Mason and James Dixon, " mathematicians and surveyors," were mutually agreed upon by the contestants, Thomas and Richard Penn, on the one part, and lord Baltirnore, the great-grandson of Cecilius, the first patentee, on the other, "to mark, run out, settle, fix, and determine all such parts of the circle, marks, lines, and boundaries as were mentioned in the several articles or commissions, and were not
.completed." The tvvo surveyors commenced their work in 1764, and did not finish it until 1767; the delay being partly owing to Indian troubles, involving negotiations with the Six Nations in their settlement. 'The line, as finally drawn, has been popularly supposed to have been the dividing line between the free and the slave states; but this is au error, as slavery existed throughout Delaware, which is both e. and n. of the line, -until abolished by the 14th amendment to the constitution. To this line is owing the peculiar tract of land known as the pan-handle," where a part of Virginia runs up between Pennsylvania and the Ohio riven—Very little is known of the two " surveyors of London," as they were styled. Mason was an assistant of Dr. Bradley at the royal observatory at Greenwich; both were members of the American philosophical society; both were sent by the royal society to the cape of Good Hope to observe the transit of Venus in 1769. Dixon died in Durham, England, in 1777; and Mason died in Pumsyl rvania in 1787.