In 1856 an effort was made to terminate the difficulties arising out of the different constructions put upon the Clayton-Bulwer treaty by the negotiation of a supplementary convention. On October 17 of that year a treaty was signed in London by the American minister and Lord Clarendon, known as the Dallas-Clarendon treaty. It provided (1) for the withdrawal of the British protectorate over the Mosquito Indians; (2) it regulated the boundaries of the Belize settlements on the basis of a compromise; and (3) it provided for a cession of the Bay Islands to Honduras, upon condition of the ratification of a treaty already negotiated between Great Britain and Honduras, which virtually erected an independent state of the islands, exempt in many particulars from the sovereignty of Honduras, and under the protectorate of Great Britain. The first two clauses were acceptable to the United States Senate, but it was deemed proper to amend the third by striking out all that part of it which contemplated the concurrence of the United States in the British treaty with Honduras, and simply to provide for a recognition by the two governments of the sovereignty of Honduras over the islands in question.[158] Great Britain rejected this amendment and the Dallas-Clarendon treaty fell through. Great Britain and the United States were thus thrown back upon the Clayton-Bulwer treaty with its conflicting interpretations. In October, 1857, the President was notified informally that the British government had decided to dispatch Sir Wm. Ouseley, a diplomatist of well-recognized authority and experience, to Central America to make a definite settlement of all matters in dispute between the United States and England; that the efforts of the new plenipotentiary would be directed to those objects which had been dealt with in the Dallas-Clarendon treaty of 1856, viz., the cession of the Bay Islands to Honduras, the substitution of the sovereignty of Nicaragua for the protectorate of England over the Mosquitos and the regulation of the frontiers of Belize; that it was the intention of Her Majesty's government to carry the Clayton-Bulwer treaty into execution according to the general tenor of the interpretation put upon it by the United States, but to do so by separate negotiation with the Central American republics, in lieu of a direct engagement with the federal government.[159] President Buchanan replied that he would be satisfied with this course and that upon receiving an official assurance to that effect, he would change the character of the message he had already prepared for Congress. On the 30th of November, 1857, the British government submitted to the United States the alternative of referring the Clayton-Bulwer treaty to the arbitration of any European power which the United States might prefer to select or of adjusting matters by negotiations with the Central American republics, as already outlined in Sir William Ouseley's prospective mission.[160]