to the arbiter was that of the highlands, to which the President's proposition directly applies, and which are designated in the treaty of peace as the northwest angle of Nova Scotia, formed by a line drawn due north from the source of the St. Croix River to the highlands dividing the rivers, etc.; that the arbiter found it impossible to decide this point, and therefore recommended a new line, different from that called for by the treaty of 1783, and which could only be established by a conventional arrangement between the two Governments; that the Government of the United States could not adopt this recommendation nor agree upon a new and conventional line without the consent of the State of Maine; that the present negotiation proposed to ascertain the boundary according to the treaty of 1783, and for this purpose, however attained, the authority of the Government of the United States was complete; that the proposition offered by the Government of the United States promised, in the opinion of the President, the means of ascertaining the true line by discovering the highlands of the treaty, but the British Government asked the United States as a preliminary concession to acquiesce in the opinion of the arbiter upon certain subordinate facts--a concession which would in effect defeat the sole object, not only of the proposition, but of the negotiation, viz, the determination of the boundary according to the treaty of 1783 by confining the negotiation to a conventional line, to which this Government had not the authority to agree. Mr. McLane also said that if by a resort to the plain rule now recommended it should be found impracticable to trace the boundary according to the definitive treaty, it would then be time enough to enter upon a negotiation for a conventional substitute for it. He stated in answer to the suggestion of Sir Charles R. Vaughan that the objection urged against the line of the arbiter would equally lie against that suggested by Mr. Livingston; that the authority of the Government to ascertain the true line of the treaty was unquestionable, and that the American proposition, by confining the course to the natural object, would be a legitimate ascertainment of that line.