To this treaty we are indeed indebted for one piece of information. It gives us--what is not to be found elsewhere--a definition of the terms single and double as applied to letters. It is strange that the Acts of 1660 and 1711, while imposing distinctive rates on single and double letters, nowhere define what single and double letters are. This omission the treaty of 1713 supplies. "That piece," the treaty provides, "is to be esteemed a single letter which hath no sealed letter inclosed, and that to be esteemed a double letter which hath inclosures and is under the weight of an ounce." It will be interesting to note how far the Post Office adhered to its own definition. On the accession of George the First, when almost every place of honour and profit under the Crown changed hands, the Post Office did not escape; and Frankland and Evelyn were succeeded by Cornwallis and Craggs. The natural tendency of the provision which had made members of the House of Commons ineligible for the office of postmasters-general was to throw the office into the hands of peers; and although this tendency did not fully develop itself until later in the century, the appointment of Lord Cornwallis was a first move in that direction. Peers have in our own time been among the ablest of the many able administrators who have presided over the Post Office; but at the beginning of the eighteenth century the conditions attaching to the appointment were in some respects different from what they are to-day. The postmasters-general had to write their own letters; their attendance was both early and late and during fixed hours; and they were expected to reside at the Post Office. Whether from a disinclination to satisfy these conditions, or on the score of health, which he was constantly pleading, Cornwallis had not been long in Lombard Street before he retired into the country, and left the conduct of affairs pretty much to his colleague. Craggs--or Craggs senior as he was commonly called, to distinguish him from his son, the Secretary of State--was an industrious, plain-spoken man; and deeply as he afterwards became implicated in the South Sea Scheme, there is no reason to suppose that his proceedings as postmaster-general would not bear inspection.