[67] How Carteret managed to retain his appointment for more than eighteen years is not the least perplexing of Post Office problems. Meanwhile the joint postmaster-generalship had undergone the following changes:-- Lord Le Despencer } From Jan. 16, 1771, Right Hon. Henry F. Thynne (afterwards Carteret)} to Dec. 11, 1781. Right Hon. Henry F. Carteret (sometime Thynne) { From Dec. 11, 1781, { to Jan. 24, 1782. Right Hon. Henry F. Carteret } From Jan. 24, 1782, Viscount Barrington } to April 25, 1782. Right Hon. Henry F. Carteret } From April 25, 1782, Earl of Tankerville } to May 1, 1783. Right Hon. Henry F. Carteret } From May 1, 1783, Lord Foley } to Jan. 7, 1784. Right Hon. Henry F. Carteret, created Lord } Carteret Jan. 29, 1784 } From Jan. 7, 1784, Earl of Tankerville (a second time) } to Sept. 19, 1786. Lord Carteret } From Sept. 19, 1786, Earl of Clarendon } to Dec. 10, 1786. Lord Carteret { From Dec. 10, 1786, { to July 6, 1787. Lord Carteret } From July 6, 1787, Lord Walsingham } to Sept. 19, 1789.